This document provides instructions for a Drosophila genetics lab that teaches students about homeobox genes and homeotic mutations. The lab takes approximately 30 days for students to complete their crosses and 50 days for the instructor to prepare stocks. Students will apply principles of genetics to analyze fly crosses and communicate their findings. They will also discuss how model organisms like Drosophila are used in biomedical research. The instructor must prepare stock populations of flies with homeotic mutations in advance and establish a dedicated work space for students.
Introduction
About Drosophila
Genome of Drosophila
Life cycle
Differentiation
Development of Drosophila
* Embryonic development
* Dorsal -ventral and
* Anterior posterior development
* Body segmentation
* Homeotic gene
Conclusion
Reference
The document describes a genetics experiment using Drosophila melanogaster (fruit flies) to study Mendelian inheritance. Students crossed flies with different eye colors (wild type vs scarlet eyes) to study monohybrid crosses. They found a 3:1 ratio of wild type to scarlet eyes in the F2 generation, supporting Mendel's law of segregation. Statistical analysis using a chi-squared test verified the results matched expected Mendelian ratios.
The engrailed gene is a segment polarity gene in Drosophila melanogaster that plays several important roles during development. It defines the posterior region of each embryonic parasegment, establishing anterior-posterior polarity. The engrailed gene also helps pattern the brain by defining borders between regions and guiding neuronal axon growth. Comparisons of engrailed DNA and protein sequences across species show it is conserved and related genes can be found in vertebrates as well.
The document summarizes a genetics experiment involving Drosophila crosses to study the inheritance of three traits: body type, eye color, and bright eyes. Two parental fly stocks were bred and their offspring observed. The results found that:
1. Sex determination followed a normal 1:1 ratio, indicating XX/XY system.
2. Eye color also followed a 1:1 ratio, with white eyes being recessive.
3. Body type and eye brightness each followed independent assortment in a 3:1 ratio.
4. However, when analyzing both traits together, the results did not match the expected 9:3:3:1 ratio, suggesting the genes are linked rather than independently assort
1. The document describes experiments conducted using fruit flies to study genetics. It examines different genetic traits such as dominant, recessive, sex-linked dominant and recessive, and lethal dominant traits.
2. For each genetic trait, it discusses the offspring results of mating fruit flies with different phenotypes, such as lobe-eyed and wild-eyed.
3. The results show that dominant traits are expressed more in offspring, recessive traits are hidden in the first generation but expressed in later generations, and sex-linked and lethal dominant traits affect males and females differently.
Genetic experiment on the offspring of drosophila melanogasterJoniqua Christopher
1) The experiment aimed to determine if mating Drosophila melanogaster in a dihybrid cross would yield results similar to Mendel's 9:3:3:1 ratio by observing inheritance of eye color (red vs white) and body color (ebony vs brown).
2) The F1 generation showed more dominant traits than recessive, but not all were dominant as in Mendel's experiments. The F2 results using a chi-square test did not match the expected 9:3:3:1 ratio.
3) Errors were made in transferring flies between generations that may have impacted the results, which were ultimately deemed inconclusive. Proper fly handling and food preparation are needed to obtain clear results.
Sexual reproduction involves the combination of genetic material from two parent cells to form a new cell. It occurs through meiosis which produces haploid sex cells with half the number of chromosomes and through fertilization where an egg and sperm join. This maintains the diploid number of chromosomes and generates genetic variation in offspring, providing advantages for adaptation and selective breeding.
The document discusses heredity and variation in organisms. It defines heredity as the transmission of traits from parents to offspring. Variation refers to the differences in traits among individuals of a species. The document lists several examples of variations in humans such as eye color, hair color, height etc. It also discusses Gregor Mendel's experiments with pea plants which laid the foundations for modern genetics through his principles of inheritance, including dominant and recessive genes.
Introduction
About Drosophila
Genome of Drosophila
Life cycle
Differentiation
Development of Drosophila
* Embryonic development
* Dorsal -ventral and
* Anterior posterior development
* Body segmentation
* Homeotic gene
Conclusion
Reference
The document describes a genetics experiment using Drosophila melanogaster (fruit flies) to study Mendelian inheritance. Students crossed flies with different eye colors (wild type vs scarlet eyes) to study monohybrid crosses. They found a 3:1 ratio of wild type to scarlet eyes in the F2 generation, supporting Mendel's law of segregation. Statistical analysis using a chi-squared test verified the results matched expected Mendelian ratios.
The engrailed gene is a segment polarity gene in Drosophila melanogaster that plays several important roles during development. It defines the posterior region of each embryonic parasegment, establishing anterior-posterior polarity. The engrailed gene also helps pattern the brain by defining borders between regions and guiding neuronal axon growth. Comparisons of engrailed DNA and protein sequences across species show it is conserved and related genes can be found in vertebrates as well.
The document summarizes a genetics experiment involving Drosophila crosses to study the inheritance of three traits: body type, eye color, and bright eyes. Two parental fly stocks were bred and their offspring observed. The results found that:
1. Sex determination followed a normal 1:1 ratio, indicating XX/XY system.
2. Eye color also followed a 1:1 ratio, with white eyes being recessive.
3. Body type and eye brightness each followed independent assortment in a 3:1 ratio.
4. However, when analyzing both traits together, the results did not match the expected 9:3:3:1 ratio, suggesting the genes are linked rather than independently assort
1. The document describes experiments conducted using fruit flies to study genetics. It examines different genetic traits such as dominant, recessive, sex-linked dominant and recessive, and lethal dominant traits.
2. For each genetic trait, it discusses the offspring results of mating fruit flies with different phenotypes, such as lobe-eyed and wild-eyed.
3. The results show that dominant traits are expressed more in offspring, recessive traits are hidden in the first generation but expressed in later generations, and sex-linked and lethal dominant traits affect males and females differently.
Genetic experiment on the offspring of drosophila melanogasterJoniqua Christopher
1) The experiment aimed to determine if mating Drosophila melanogaster in a dihybrid cross would yield results similar to Mendel's 9:3:3:1 ratio by observing inheritance of eye color (red vs white) and body color (ebony vs brown).
2) The F1 generation showed more dominant traits than recessive, but not all were dominant as in Mendel's experiments. The F2 results using a chi-square test did not match the expected 9:3:3:1 ratio.
3) Errors were made in transferring flies between generations that may have impacted the results, which were ultimately deemed inconclusive. Proper fly handling and food preparation are needed to obtain clear results.
Sexual reproduction involves the combination of genetic material from two parent cells to form a new cell. It occurs through meiosis which produces haploid sex cells with half the number of chromosomes and through fertilization where an egg and sperm join. This maintains the diploid number of chromosomes and generates genetic variation in offspring, providing advantages for adaptation and selective breeding.
The document discusses heredity and variation in organisms. It defines heredity as the transmission of traits from parents to offspring. Variation refers to the differences in traits among individuals of a species. The document lists several examples of variations in humans such as eye color, hair color, height etc. It also discusses Gregor Mendel's experiments with pea plants which laid the foundations for modern genetics through his principles of inheritance, including dominant and recessive genes.
Introduction
History
Geographical distribution
Genome Structure
Anatomy and Life Cycle
Significance of Arabidopsis in Plant Genetics
Conclusion
References.
Homeobox genes are a large family of genes that regulate embryonic development. They were first discovered in fruit flies and contain a DNA sequence called the homeodomain that encodes a protein regulating transcription of other genes. In humans, homeobox genes are organized into four clusters (A-D) on different chromosomes and regulate body patterning along the head-to-tail axis. Mutations in homeobox genes can lead to developmental disorders like aniridia, synpolydactyly, and Axenfeld-Rieger syndrome. There is potential to use homeobox genes like PDX-1 in gene therapy to generate new tissues like pancreatic beta cells in the liver to treat diseases like diabetes.
hox genes and its role in development both in human and drosophila . homeotic genes. homeobox genes. developmental biology. different types of homeotic genes in drosophila and human. deficiencydiseases due to lack of hox genes in human
Genomic conflict-It arises when genes inside a genome are not transmitted by the same rules
Genes that cause such genomic conflict are called selfish genetic elements (also selfish DNA, ultra-selfish genes, genetic parasites) and can be harmful to the individual.
So selfish gene can be defined as stretches of DNA (genes, fragments of genes, noncoding DNA, portions of chromosomes, whole chromosomes, or sets of chromosomes) that act narrowly to advance their own interests—in other words, replication at the expense of the larger organism.
Here it also presented about what is genomic conflict, types of it, cytoplasmic inheritance, its relation with genomic conflict, ABC model, Molecular mechanism of CMS, Pollen hypothesis, ATP hypothesis, etc.
The document discusses the esophageal glands of plant parasitic nematodes. It notes that these glands contain secretory cells that produce proteins (the secretome) involved in parasitism. These secretions are injected through the nematode's stylet into host plant cells and alter the cells' gene expression and morphology, transforming them into feeding sites for the nematode. The dorsal gland helps develop and maintain these feeding sites, while the subventral glands are most active during parasitism in the infective juvenile stage.
Zebra Fish- Genome, Morphology,Embryonic Development, A model organism Subhradeep sarkar
The zebrafish is a popular model organism used in scientific research due to its many advantages. It has a fully sequenced genome that is similar to humans and contains around 22,000 genes. The zebrafish develops rapidly, with major organ systems evident within days of fertilization. This, along with external fertilization and transparent embryos, makes early development easy to observe. The zebrafish genome also contains regions that are syntenic with human chromosomes, making it useful for studying human health and disease.
Evidences of evolution from patterns of developmentHimanshi Chauhan
The document provides evidence for evolution from patterns of development in organisms. It discusses several lines of evidence, including:
1) Homologous structures that have a common origin but different functions, such as the thorn of a plant and tendril, providing evidence of descent from a common ancestor.
2) Analogous structures that have a similar function but different origins, such as wings of insects and birds, indicating similar adaptations.
3) Vestigial structures that were functional in ancestors but no longer serve a purpose, found in both plants and animals including humans.
4) Embryological evidence from plant and animal embryos that show similarities in early stages, indicating common ancestry.
This document outlines the key topics and learning objectives for a course on reproduction. It covers:
1) Asexual and sexual reproduction - defining each type and discussing their advantages/disadvantages.
2) Sexual reproduction in plants - examining flower structures, pollination, seed and fruit dispersal.
3) Sexual reproduction in humans - anatomy and functions of male/female reproductive systems, fertilization, early development, placenta/umbilical cord function, breastfeeding vs. bottlefeeding, HIV transmission and prevention.
Welcome to the world of Homeotic genes. In this presentation I talk about the interesting history behind homeotic genes as to how it was discovered. Also, the various deformities in Drosophila related to mutations in homeotic genes and the characteristics of homeotic genes. I also talk about hox genes in humans and their function.
In the simplest of words, heredity refers to the passing of traits or characteristics through genes from one generation (parent) to the other generation (offspring). Heredity is very evidently seen in sexual reproduction. ... Variation is important because it contributes to the evolution and forms the basis of heredity.
Reproduction allows organisms to produce new individuals of their own kind and maintain their existence across generations. It occurs through either asexual or sexual reproduction. Asexual reproduction involves a single parent and produces offspring that are genetically identical, while sexual reproduction involves two parents and produces offspring with genetic variation. DNA replication and cell division are basic steps in reproduction, and variations introduced during DNA copying are the basis of evolution and allow species to adapt over time.
- The document describes an experiment involving Drosophila melanogaster flies to study genetic inheritance patterns.
- Wild type and sepia mutant flies were crossed, producing F1 offspring. The F1 offspring were then observed to determine phenotypic ratios.
- A total of 24 male and 16 female parental flies were obtained initially. After crosses and observations, 19 female and 20 male F1 offspring were observed, showing a 1:1 phenotypic ratio as expected based on Mendelian genetics.
Cloning is the process of creating a genetically identical copy of an organism. The document outlines the history of cloning experiments from sea urchins in 1894 to Dolly the sheep in 1996. It describes the main types as DNA cloning, reproductive cloning, and therapeutic cloning. Reproductive cloning aims to create copies of existing organisms while therapeutic cloning produces stem cells for medical research. The document discusses advantages like maintaining good genetics in animals, risks like low success rates and health issues in clones, and applications in biomedical research and livestock breeding.
This document summarizes the molecular mechanisms of sex determination in Drosophila and humans. In Drosophila, sex is determined by the ratio of X chromosomes to autosomes (X:A ratio). A ratio greater than 1 leads to female development, while a ratio of less than 1 leads to male development. In humans, the presence of the SRY gene on the Y chromosome leads to testis development and a male phenotype, while its absence leads to ovarian development and a female phenotype. Key genes involved include Sxl, tra, and dsx in Drosophila, and SRY, Sox9, and FGF9 in humans. The document provides details on how these genes regulate downstream targets to control sexual differentiation in both organisms.
This document discusses genetics and evolution. It provides background on heredity, variation, Mendel's experiments with pea plants, and his laws of inheritance. It describes how traits are passed from parents to offspring through genes, alleles, dominance, and segregation. It discusses evidence for evolution, including homologous and vestigial structures, as well as theories like natural selection and genetic drift. The document also covers modern concepts like DNA, chromosomes, mutation, and molecular evidence supporting common descent.
This document provides information about reproduction in various organisms. It discusses how reproduction allows for the transfer of DNA from parents to offspring, ensuring survival of species. It notes that while DNA copying is important for maintaining body designs, variations in offspring through small changes in DNA allow for adaptation to changing environments and evolution of new species. The document then describes different types of reproduction like asexual reproduction, which produces offspring from a single parent through processes like budding and spore formation, and sexual reproduction, which involves two parents fusing male and female gametes. It provides details on human sexual reproduction and pregnancy.
The document discusses development in Drosophila melanogaster (fruit flies). It describes how maternal molecules establish body axes in the early embryo before cell differentiation. Segmentation genes are then expressed in gradients controlled by these maternal factors and establish the basic body plan. These include gap, pair-rule and segment polarity genes. Finally, homeotic genes specify the identity of each body segment and control structure formation. This cascade of gene regulation results in the distinct segments that make up the adult fly body.
Effects of Metformin, Pioglitazone and Aqueous Extract of Delonix Regia on Bl...iosrjce
The effects of Delonix regia extract (d200mg, d300mg, and d400mg), metformin (m8.3mg, m12.5mg
and m16.5mg), pioglitazone (p0.5mg, p0.7mg and p0.9mg) and combined formulation of metformin and extract
(m6.25d150mg) on glycated hemoglobin status in streptozotocin-induced diabetic Albino wistar rats. Diabetic
status of these rats was assessed by estimating fasting blood glucose levels. A total of 150 albino rats were used
for the investigation and were grouped into twelve groups of twelve rats each as follows; Group I: normal
control rats (NCR). Group II: Diabetic control rats (DCR). Group III: Diabetic rats treated with d200mg.
Group IV: Diabetic rats treated with d300mg. Group V: Diabetic rats treated with d400mg. Group VI: Diabetic
rats treated with m8.3mg. Group VII: Diabetic rats treated with m12.5mg. Group VIII: Diabetic rats treated
with m16.5mg. Group IX: Diabetic rats treated with p0.5mg. Group X: Diabetic rats treated with p0.75mg.
Group XI: Diabetic rats treated with p1.0mg. Group XII: Diabetic rats treated with m125d300mg each for male
and female respectively, for a total of 56 days. After every two weeks interval of treatment for eight weeks three
rats from each group were sacrificed and blood sample were collected and analyzed for various parameters.
The result obtained showed an elevated level of glycated hemoglobin in diabetic-induced wistar albino rats
compared with normal control rats. However, there was reversal of the effects when treated with the
drug/extract. Also there was reduction in the blood glucose level of the diabetic rats treated with metformin
(from 6.37±0.69 to 5.20±0.62mmol/l), pioglitazone (from 7.30±0.21mmol/l to 4.70±0.46), aqueous extract of
Delonixregia (from 8.20±0.81mmol/l to 6.10±0.60) and combined formulation of metformin and extract (from
7.81±0.34 to 4.80±0.17), at p<0.05 confidence level when compared with diabetic control rats in the various
weeks of treatment respectively
Introduction
History
Geographical distribution
Genome Structure
Anatomy and Life Cycle
Significance of Arabidopsis in Plant Genetics
Conclusion
References.
Homeobox genes are a large family of genes that regulate embryonic development. They were first discovered in fruit flies and contain a DNA sequence called the homeodomain that encodes a protein regulating transcription of other genes. In humans, homeobox genes are organized into four clusters (A-D) on different chromosomes and regulate body patterning along the head-to-tail axis. Mutations in homeobox genes can lead to developmental disorders like aniridia, synpolydactyly, and Axenfeld-Rieger syndrome. There is potential to use homeobox genes like PDX-1 in gene therapy to generate new tissues like pancreatic beta cells in the liver to treat diseases like diabetes.
hox genes and its role in development both in human and drosophila . homeotic genes. homeobox genes. developmental biology. different types of homeotic genes in drosophila and human. deficiencydiseases due to lack of hox genes in human
Genomic conflict-It arises when genes inside a genome are not transmitted by the same rules
Genes that cause such genomic conflict are called selfish genetic elements (also selfish DNA, ultra-selfish genes, genetic parasites) and can be harmful to the individual.
So selfish gene can be defined as stretches of DNA (genes, fragments of genes, noncoding DNA, portions of chromosomes, whole chromosomes, or sets of chromosomes) that act narrowly to advance their own interests—in other words, replication at the expense of the larger organism.
Here it also presented about what is genomic conflict, types of it, cytoplasmic inheritance, its relation with genomic conflict, ABC model, Molecular mechanism of CMS, Pollen hypothesis, ATP hypothesis, etc.
The document discusses the esophageal glands of plant parasitic nematodes. It notes that these glands contain secretory cells that produce proteins (the secretome) involved in parasitism. These secretions are injected through the nematode's stylet into host plant cells and alter the cells' gene expression and morphology, transforming them into feeding sites for the nematode. The dorsal gland helps develop and maintain these feeding sites, while the subventral glands are most active during parasitism in the infective juvenile stage.
Zebra Fish- Genome, Morphology,Embryonic Development, A model organism Subhradeep sarkar
The zebrafish is a popular model organism used in scientific research due to its many advantages. It has a fully sequenced genome that is similar to humans and contains around 22,000 genes. The zebrafish develops rapidly, with major organ systems evident within days of fertilization. This, along with external fertilization and transparent embryos, makes early development easy to observe. The zebrafish genome also contains regions that are syntenic with human chromosomes, making it useful for studying human health and disease.
Evidences of evolution from patterns of developmentHimanshi Chauhan
The document provides evidence for evolution from patterns of development in organisms. It discusses several lines of evidence, including:
1) Homologous structures that have a common origin but different functions, such as the thorn of a plant and tendril, providing evidence of descent from a common ancestor.
2) Analogous structures that have a similar function but different origins, such as wings of insects and birds, indicating similar adaptations.
3) Vestigial structures that were functional in ancestors but no longer serve a purpose, found in both plants and animals including humans.
4) Embryological evidence from plant and animal embryos that show similarities in early stages, indicating common ancestry.
This document outlines the key topics and learning objectives for a course on reproduction. It covers:
1) Asexual and sexual reproduction - defining each type and discussing their advantages/disadvantages.
2) Sexual reproduction in plants - examining flower structures, pollination, seed and fruit dispersal.
3) Sexual reproduction in humans - anatomy and functions of male/female reproductive systems, fertilization, early development, placenta/umbilical cord function, breastfeeding vs. bottlefeeding, HIV transmission and prevention.
Welcome to the world of Homeotic genes. In this presentation I talk about the interesting history behind homeotic genes as to how it was discovered. Also, the various deformities in Drosophila related to mutations in homeotic genes and the characteristics of homeotic genes. I also talk about hox genes in humans and their function.
In the simplest of words, heredity refers to the passing of traits or characteristics through genes from one generation (parent) to the other generation (offspring). Heredity is very evidently seen in sexual reproduction. ... Variation is important because it contributes to the evolution and forms the basis of heredity.
Reproduction allows organisms to produce new individuals of their own kind and maintain their existence across generations. It occurs through either asexual or sexual reproduction. Asexual reproduction involves a single parent and produces offspring that are genetically identical, while sexual reproduction involves two parents and produces offspring with genetic variation. DNA replication and cell division are basic steps in reproduction, and variations introduced during DNA copying are the basis of evolution and allow species to adapt over time.
- The document describes an experiment involving Drosophila melanogaster flies to study genetic inheritance patterns.
- Wild type and sepia mutant flies were crossed, producing F1 offspring. The F1 offspring were then observed to determine phenotypic ratios.
- A total of 24 male and 16 female parental flies were obtained initially. After crosses and observations, 19 female and 20 male F1 offspring were observed, showing a 1:1 phenotypic ratio as expected based on Mendelian genetics.
Cloning is the process of creating a genetically identical copy of an organism. The document outlines the history of cloning experiments from sea urchins in 1894 to Dolly the sheep in 1996. It describes the main types as DNA cloning, reproductive cloning, and therapeutic cloning. Reproductive cloning aims to create copies of existing organisms while therapeutic cloning produces stem cells for medical research. The document discusses advantages like maintaining good genetics in animals, risks like low success rates and health issues in clones, and applications in biomedical research and livestock breeding.
This document summarizes the molecular mechanisms of sex determination in Drosophila and humans. In Drosophila, sex is determined by the ratio of X chromosomes to autosomes (X:A ratio). A ratio greater than 1 leads to female development, while a ratio of less than 1 leads to male development. In humans, the presence of the SRY gene on the Y chromosome leads to testis development and a male phenotype, while its absence leads to ovarian development and a female phenotype. Key genes involved include Sxl, tra, and dsx in Drosophila, and SRY, Sox9, and FGF9 in humans. The document provides details on how these genes regulate downstream targets to control sexual differentiation in both organisms.
This document discusses genetics and evolution. It provides background on heredity, variation, Mendel's experiments with pea plants, and his laws of inheritance. It describes how traits are passed from parents to offspring through genes, alleles, dominance, and segregation. It discusses evidence for evolution, including homologous and vestigial structures, as well as theories like natural selection and genetic drift. The document also covers modern concepts like DNA, chromosomes, mutation, and molecular evidence supporting common descent.
This document provides information about reproduction in various organisms. It discusses how reproduction allows for the transfer of DNA from parents to offspring, ensuring survival of species. It notes that while DNA copying is important for maintaining body designs, variations in offspring through small changes in DNA allow for adaptation to changing environments and evolution of new species. The document then describes different types of reproduction like asexual reproduction, which produces offspring from a single parent through processes like budding and spore formation, and sexual reproduction, which involves two parents fusing male and female gametes. It provides details on human sexual reproduction and pregnancy.
The document discusses development in Drosophila melanogaster (fruit flies). It describes how maternal molecules establish body axes in the early embryo before cell differentiation. Segmentation genes are then expressed in gradients controlled by these maternal factors and establish the basic body plan. These include gap, pair-rule and segment polarity genes. Finally, homeotic genes specify the identity of each body segment and control structure formation. This cascade of gene regulation results in the distinct segments that make up the adult fly body.
Effects of Metformin, Pioglitazone and Aqueous Extract of Delonix Regia on Bl...iosrjce
The effects of Delonix regia extract (d200mg, d300mg, and d400mg), metformin (m8.3mg, m12.5mg
and m16.5mg), pioglitazone (p0.5mg, p0.7mg and p0.9mg) and combined formulation of metformin and extract
(m6.25d150mg) on glycated hemoglobin status in streptozotocin-induced diabetic Albino wistar rats. Diabetic
status of these rats was assessed by estimating fasting blood glucose levels. A total of 150 albino rats were used
for the investigation and were grouped into twelve groups of twelve rats each as follows; Group I: normal
control rats (NCR). Group II: Diabetic control rats (DCR). Group III: Diabetic rats treated with d200mg.
Group IV: Diabetic rats treated with d300mg. Group V: Diabetic rats treated with d400mg. Group VI: Diabetic
rats treated with m8.3mg. Group VII: Diabetic rats treated with m12.5mg. Group VIII: Diabetic rats treated
with m16.5mg. Group IX: Diabetic rats treated with p0.5mg. Group X: Diabetic rats treated with p0.75mg.
Group XI: Diabetic rats treated with p1.0mg. Group XII: Diabetic rats treated with m125d300mg each for male
and female respectively, for a total of 56 days. After every two weeks interval of treatment for eight weeks three
rats from each group were sacrificed and blood sample were collected and analyzed for various parameters.
The result obtained showed an elevated level of glycated hemoglobin in diabetic-induced wistar albino rats
compared with normal control rats. However, there was reversal of the effects when treated with the
drug/extract. Also there was reduction in the blood glucose level of the diabetic rats treated with metformin
(from 6.37±0.69 to 5.20±0.62mmol/l), pioglitazone (from 7.30±0.21mmol/l to 4.70±0.46), aqueous extract of
Delonixregia (from 8.20±0.81mmol/l to 6.10±0.60) and combined formulation of metformin and extract (from
7.81±0.34 to 4.80±0.17), at p<0.05 confidence level when compared with diabetic control rats in the various
weeks of treatment respectively
This document describes using fruit flies (Drosophila melanogaster) as a model for studying genetic relationships. Fruit flies breed quickly and have observable traits, allowing researchers to deduce genotypes from phenotypes by observing traits when selecting parents and analyzing data using the Chi-squared test. The tutorial guides the user through monohybrid crosses to determine the genotypes of parent flies by recording phenotypes, pedigree charts, data collection, and statistical analysis.
1) The document presents a mathematical model of tumor growth and the immune response mediated by natural killer (NK) cells and CD8+ T cells.
2) The model uses a system of differential equations to describe the interactions between tumor cells and immune cells over time.
3) The model can predict which patients may positively respond to cancer immunotherapy based on the dynamics of the immune response to tumor growth modeled by the differential equations.
Drosophila (fruit flies) are commonly used as a model for neural development research due to several advantages: they are inexpensive to culture, have a small and well-known genome, a short lifecycle, and many genetic tools available. Thomas Hunt Morgan established Drosophila as a genetic model in the early 1900s and won the 1933 Nobel Prize for this work. The Drosophila genome was fully sequenced in 2000, aiding further research. Drosophila have a 10-day lifecycle and well-studied embryonic neural development and neuroblast mapping. Genetic tools like P-element insertions and the UAS-GAL4 system allow for gene overexpression and knockdown experiments. Drosophila research has provided insights into neural pathways, phot
- The student conducted a fruit fly experiment to observe inheritance patterns of mutants in the F1 and F2 generations.
- In the F1 generation, 4 males exhibited the white eye mutation. The F2 generation showed wild type, white eye, vestigial wing, and combined mutants.
- Chi-square analysis found differences between observed and expected phenotypic ratios, suggesting the results did not match expectations likely due to not reaching the target number of flies.
- The experiment demonstrated Mendelian genetics and inheritance patterns but did not precisely match ratios likely due to insufficient sample size.
Gametogenesis is the process of forming gametes (eggs and sperm) from gonads through meiosis. In males, spermatogenesis occurs in the testes through spermatocytogenesis, meiosis I and II, and spermiogenesis. In females, oogenesis occurs in the ovaries through follicular development, ovulation, and the luteal phase. Infertility can result from problems with gametogenesis like inflammation of the testes or failure of the ovaries to ovulate, as well as issues with the fallopian tubes, cervix, or uterus.
This document discusses various animal models used for research including invertebrate models like Drosophila and C. elegans, rodent models, rabbit models, and large animal models. These models are used to study processes like genetics, development, and disease due to their similarities to humans. Drosophila and C. elegans have been important for discoveries in development and genetics. Rodent models are widely used due to their similarities to humans and short lifespans. Larger animal models are needed for pre-clinical research due to closer mimicry of human physiology. A variety of animal models at different sizes are essential for advancing biomedical research.
The Chi-squared test is a statistical test used to compare observed data with data you would expect to obtain according to a specific hypothesis. It allows you to determine if any difference between the observed and expected results is statistically significant or likely due to chance. The test works by calculating a chi-squared statistic and using it to determine the probability that the observed differences could have occurred by chance.
Exploring ‘’Type 2 diabetes’’ using Drosophila as a study model By MOHD SAIFU...SYED ASSIM HAQ
This document discusses diabetes and the use of Drosophila melanogaster (fruit flies) as a model organism to study type 2 diabetes. It provides background on diabetes, describing it as resulting from insufficient insulin production or insulin resistance. It then outlines advantages of using fruit flies as a model, such as their short lifespan, sequenced genome, and ability to produce large numbers of offspring. Several genetic pathways involved in glucose intolerance in fruit flies are also discussed. The document concludes by suggesting future areas of research using the fruit fly model to study human diabetes genes and their functions.
Apoptosis, or programmed cell death, is an important physiological process that eliminates unwanted or damaged cells. There are two main pathways that trigger apoptosis - the extrinsic or death receptor pathway, and the intrinsic or mitochondrial pathway. The extrinsic pathway involves death receptors and ligands that activate caspase enzymes. The intrinsic pathway occurs in response to cellular stress and involves mitochondrial outer membrane permeabilization and the release of proteins like cytochrome c. This forms the apoptosome complex and activates caspase-9 and caspase-3, leading to apoptosis. Apoptosis is a highly regulated process involving Bcl-2 family proteins, caspase enzymes, and characteristic morphological changes including cell shrinkage, nuclear fragmentation, and membrane blebbing. Assays to detect
Giving overview of human embryonic development including spermatogenesis, oogenesis, fertilization, gastrulation, cleavage, extraembryonic layers and pregnancy
Gametogenesis is the process by which haploid gametes are formed from diploid germ cells through meiosis. It occurs in the gonads (ovaries in females and testes in males) and results in the production of eggs in females through oogenesis and sperm in males through spermatogenesis. Both processes involve germ cells undergoing cell division and differentiation through meiosis to form mature haploid gametes - eggs in females and sperm in males - that can fuse during fertilization to form a new diploid organism.
Vermicomposting is a process of composting organic wastes using earthworms. Certain species of earthworms are used to enhance the waste conversion process and produce a better quality compost. Red earthworms are commonly used as they efficiently convert organic matter into vermicompost within 45-50 days through their burrowing, castings and intestinal secretions. Vermicompost contains more nutrients in readily available forms compared to traditional compost and improves soil health, structure, fertility and plant growth.
Apoptosis, also known as programmed cell death, is a natural process by which cells self-destruct in response to internal or external signals. It is distinct from necrosis in that it involves chromatin condensation, cell shrinkage, and preservation of organelles, allowing for rapid engulfment by neighboring cells without inflammation. Apoptosis is initiated through either the intrinsic mitochondrial pathway or the extrinsic death receptor pathway and is executed by caspases, a family of cysteine proteases. It plays an essential role in development and homeostasis by removing damaged or unneeded cells.
The document describes an algorithm for detecting R-peaks in an electrocardiogram (ECG) signal using MATLAB. It involves several steps: (1) removing low frequency components from the ECG signal using FFT, (2) finding local maxima using a windowed filter, (3) removing small values and storing significant peaks, (4) adjusting the filter size and repeating steps 2-3. The algorithm is demonstrated on two ECG data samples, showing the processed signal and detected peaks at each step. Finally, the document explains how to implement the algorithm in a neural network using the MATLAB Neural Network Toolbox.
This document reports on the isolation and analysis of a Hox gene, DoxC, from the dicyemid mesozoan Dicyema orientale. Analysis of the DoxC gene sequence indicates that it is most similar to the 'middle' group of Hox genes found in triploblasts. Additionally, the presence of a diagnostic peptide motif encoded near the homeodomain implies that Dicyema orientale is a member of the Lophotrochozoa and is related to phyla such as platyhelminths, molluscs, nemerteans, brachiopods and annelids. This leads the authors to conclude that dicyemids are secondarily simplified higher protost
The document describes an experiment on inheritance patterns in dragon wings. The hypothesis is that normal wings are dominant to butterfly wings. The F1 generation from a cross of normal-winged and butterfly-winged parents is predicted to have 100% normal wings. The F2 generation is predicted to show a 3:1 Mendelian ratio of normal to butterfly wings. The results of crosses between the generations are presented.
Drosophila melanogaster is a popular model organism for teaching biology. It has a short lifespan of 2 weeks, allowing many generations to be studied quickly. It is easy and inexpensive to culture in large numbers. Students can observe Drosophila's morphology, life cycle, sexual dimorphism, and mutants. Activities include extracting and staining polytene chromosomes from salivary glands to observe banding patterns. Drosophila is a useful tool for teaching genetics and demonstrates principles like dominance, inheritance of sex-linked traits, and similarities to human diseases.
Drosophila melanogaster, or the fruit fly, is a widely used model organism in scientific research due to its short lifespan, low maintenance requirements, and genetic tractability. Thomas Hunt Morgan established Drosophila as a genetic model in 1909 and made important discoveries in sex linkage, gene location on chromosomes, and genetic mapping. Drosophila has a simple genome of four chromosome pairs and around 13,000 genes, and its development and behaviors can be easily manipulated and studied using genetic tools like mutagenesis, transgenesis, and RNA interference.
An experiment was conducted using Drosophila melanogaster to determine how dominant and recessive genes influence offspring traits. Offspring from crosses between different fly phenotypes were observed. It was hypothesized that the offspring would exhibit either recessive or dominant traits based on the parents' genotypes. Punnett squares were constructed for sample crosses and showed that offspring would always be heterozygous for the dominant wildtype trait when one parent was wildtype. The results supported the hypothesis by demonstrating Mendelian inheritance patterns in the fruit flies.
The word "Metrosideros" is derived from two Greek words:
- "Metra" meaning "core" or "heart", referring to the durability and hardness of the wood.
- "Sideron" meaning "iron", also referring to the durability and hardness of the wood.
So combined, "Metrosideros" means "iron-hearted trees", describing the durable, hard wood of trees in this genus.
bacterial systematics in the diversity of bacteriatanvirastogi16
This document provides an overview of bacterial systematics and taxonomy. It discusses the key concepts of classification, identification, nomenclature, and evolutionary relationships. The three main types of systematics are described as evolutionary, numerical, and phylogenetic. The importance of taxonomy is explained for effective communication, cataloging species, and aiding research. Key methods for bacterial classification discussed include phenotypic characterization, analysis of rRNA sequences, multilocus sequence analysis, restriction fragment length polymorphism, and fatty acid methyl ester profiling.
This document examines various life history traits of dicyemids to understand their reproductive strategies and adaptations to living as endoparasites in cephalopod renal organs. It finds that dicyemids have a hermaphroditic gonad that produces roughly equal numbers of eggs and sperm. Fecundity increases with adult body size. Embryo size correlates with host size, suggesting host factors influence dispersal and infection of new hosts. While individual fecundity is low, total reproductive capacity per community is high due to asexual multiplication within the host. Adult size appears constrained by the volume and features of the renal habitat within different host species.
Menders experiments were conducted using garden peas. Why would human.pdfisenbergwarne4100
Menders experiments were conducted using garden peas. Why would humans be an awful
choice for an experimental organism (give at least 3 reasons)? Give an example of an animal that
would be better sorted for genetics experiments. In Mendel\'s experiments, a plant with purple
flowers was crossed with a plant having white flowers. Explain why white flowers disappeared
in the F_1 generation and reappeared in the F_2. Your pet rabbit has curly fur. After seeking
advice from a rabbit breeder, you learn that curly fur is a dominant trait, but you want to know
the precise genotype of your pet. Describe how you could find out. Describe the inheritance of
ABO blood types in humans and explain why individuals with type O are universal donors while
individuals with type AB are universal acceptors. Describe the nature vs. nurture debate. In your
explanation, give an example of a trait that is controlled entirely by nature and one that is heavily
influenced by both nature and nurture.
Solution
Answer:
1. Studying human genetics is unlike studying the genetics of any other organism. In many ways,
humans are very poor model organisms for genetics. Long generation times make for slow
progress when doing genetic crosses, which brings us to another problem with human genetics:
The inability to make controlled crosses.
So, any human geneticist that tried to make controlled human crosses would most likely be
considered a very disturbed criminal and not a brilliant scientist. Besides, humans usually only
have one child at a time, which makes it really difficult to generate numbers of offspring that can
achieve statistical significance. On top of all this, there\'s the issue of genetic manipulation. Key
genetic techniques, like mutation screening and transgenics, are completely off-limits to human
geneticists.
Drosophila melanogaster (Fruit fly) would be better suited as a model organism for genetics
experiments.
1. The relationship between fruit fly and human genes is so close that often the sequences of
newly discovered human genes, including disease genes, can be matched with equivalent genes
in the fly.
2. 75 per cent of the genes that cause disease in humans are also found in the fruit fly.
3. Drosophila have a short, simple reproduction cycle. It is normally about 8-14 days, depending
on the environmental temperature. This means that several generations can be observed in a
matter of months.
4. Fruit fly are small (3 mm long) but not so small that they can’t be seen without a microscope.
This allows scientists to keep millions of them in the laboratory at a time.
5. They are inexpensive to maintain in the laboratory.
6. They require a simple diet consisting of simple sources of carbohydrates (cornmeal) and
proteins (yeast extract).
7. The only care they need is having their food changed regularly (every 10-14 days at 25C or 5-
6 weeks at 18C).
8. Drosophila have ‘polytene’ chromosomes, which means that they are oversized and have
barcode-like banding patterns.
This document describes the classification, morphology, behaviors, and medical importance of flies, sandflies, fleas, and cockroaches. It notes that flies belong to the order Diptera and includes disease-transmitting species like houseflies. Sandflies are in the order Psychodidae and can transmit leishmaniasis. Fleas are ectoparasites that belong to the order Siphonaptera and transmit plague and epidemic typhus. All four undergo complete metamorphosis from egg to larva to pupa to adult. As vectors, they can transmit pathogens mechanically or biologically and cause diseases and infections in humans. Prevention focuses on environmental modification and use of insecticides, screens, and personal protection measures
Unit 8: Rare and Uncultured Microbes
LECTURE LEARNING GOALS
1. Describe the phyla containing rare bacteria: Deinococcus/Thermus, Chlamydia & Planctomycetes.
2. Describe the sequencing methods used to understand uncultured microbes. Explain the Eocyte hypothesis and how this model differs from the three domain tree of life.
3. For the cultured microbes, describe major characteristics for the 13 bacterial phyla, and explain why some microbe remain uncultivated.
6
Developmental mechanisms of evolutionary changeMerlyn Denesia
This document summarizes key concepts in developmental biology and evolution. It discusses how changes in developmental pathways and gene regulation allow for morphological evolution while maintaining homologous structures. Modularity allows changes in certain body parts without disrupting others. Development is constrained by physical laws, developmental mechanisms, and phylogenetic history. Changes accumulate over generations through mutations affecting timing, scaling, duplication, and co-option of genetic and developmental mechanisms.
Caenorhabditis elegans is a tiny, free-living nematode found worldwide. Newly hatched larvae are 0.25 millimeters long and adults are 1 millimeter long. Their small size means that the animals are usually observed with either dissecting microscopes, which generally allow up to 100X magnification, or compound microscopes, which allow up to 1000X magnification. Because C. elegans is transparent, individual cells and subcellular details are easily visualized using Nomarski (differential interference contrast, DIC) optics.
C. elegans has a rapid life cycle and exists primarily as a self-fertilizing hermaphrodite, although males arise at a frequency of <0.2%. These features have helped to make C. elegans a powerful model of choice for eukaryotic genetic studies. In addition, because the animal has an invariant numbers of somatic cells, researchers have been able to track the fate of every cell between fertilization and adulthood in live animals and to generate a complete cell lineage. Researchers have also reconstructed the shape of all C. elegans cells from electron micrographs, including each of the 302 neurons of the adult hermaphrodite. Moreover, because of the invariant wild-type cell lineage and neuroanatomy of C. elegans, mutations that give rise to developmental and behavioral defects are readily identified in genetic screens. Finally, because C. elegans was the first multicellular organism with a complete genome sequence, forward and reverse genetics have led to the molecular identification of many key genes in developmental and cell biological processes.
The experimental strengths and the similarities between the cellular and molecular processes present in C. elegans and other animals across evolutionary time (metabolism, organelle structure and function, gene regulation, protein biology, etc.) have made C. elegans an excellent organism with which to study general metazoan biology. At least 38% of the C. elegans protein-coding genes have predicted orthologs in the human genome, 60-80% of human genes have an ortholog in the C. elegans genome, and 40% of genes known to be associated with human diseases have clear orthologs in the C. elegans genome. Thus, many discoveries in C. elegans have relevance to the study of human health and disease.
Homeotic genes, such as Hox genes, direct embryonic development by regulating the formation of body structures. In fruit flies, mutations in homeotic genes can result in abnormal growth like legs on the head. Researchers like Lewis, Wieschaus, and Nüsslein-Volhard discovered the role of homeotic genes in fly development and were awarded the Nobel Prize. Homeotic genes are conserved across species and in humans are organized into four clusters that guide development along the head-to-tail axis.
This document provides an overview of genetics, including its historical development, key concepts, related disciplines, importance, and tools used to study it. It discusses how genetics has evolved from early theories of heredity and variation proposed by Aristotle and Lamarck to modern concepts established by Mendel's experiments and discoveries like DNA structure by Watson, Crick, and others. The three main divisions of genetics are transmission, molecular, and population genetics. Genetics is important for fields like agriculture and forensics, and tools include DNA fingerprinting, gene therapy, and genetically engineered products.
Model organisms are non-human species that are widely studied in laboratories to help scientists understand biological processes. They are usually easy to maintain and breed in a lab setting. The document discusses several important model organisms including mice, fruit flies, yeast, and bacteria. It provides details on their genomes, uses for research, and similarities to humans that make them valuable models. Key model organisms like mice and fruit flies have been widely used to study genetics, development, and disease due to their small genomes and short lifecycles.
1. The document discusses how zoology provides an essential foundation for understanding modern biological research, like genomics and parasitic diseases. It gives examples of how studying the taxonomy and biology of schistosomes and body lice has helped answer interesting evolutionary questions.
2. It then focuses on schistosomes, parasitic flatworms that cause schistosomiasis. Genomic studies have helped reveal genes involved in the parasite's complex lifecycle and ability to infect different hosts. However, drug resistance requires identifying new drug targets.
3. It also discusses how genomic analysis of the body louse determined that humans began regularly wearing clothing, by tracing the evolutionary divergence of head and body lice.
1. The document discusses various aspects of fungal genetics including the life cycles, modes of reproduction, and nuclear states of fungi.
2. It notes that fungi typically have haploid vegetative states and undergo plasmogamy and karyogamy during sexual reproduction, followed immediately by meiosis.
3. The document also discusses asexual reproduction in fungi through spores, as well as parasexual reproduction which involves nuclear fusion without meiosis.
Note There are more questions than usual, so you will n.docxhenrymartin15260
Note: There are more questions than usual, so you will need to figure out how to write less in answer to some of the questions and more for others. To be complete and specific enough to do well, you will need to plan and edit these carefully to fit into the two-page format.
Good luck.
1. Discuss the Nanchan Temple as a typical example of ancient Chinese architecture. What are the key characteristics of form, material and structure, how do they relate directly to the natural environment of ancient China, and how do these traits relate to the key cultural concerns and ways of thinking in ancient Chinese society? In other words, how is it typical of ancient Chinese architecture in general, and how can you use it as an example of some of the “big ideas” (for China) discussed in class?
2. Now consider the Ise Shrine in the same way? What is Japanese about it, and how does it exemplify several of the main ideas we discussed? How would you distinguish it from the Nanchan Temple? What’s different, but also what is similar, and why? Remember to consider the site (designed landscape) immediately around the central shrine buildings, as it has important implications for answering the question.
3. a) How did Confucian philosophy influence or parallel any aspect of ancient Chinese design? (Explain two examples of links between Confucianism and design we talked about.)
b) How did Daoism influence ancient Chinese design? Be specific – remember that Daoism has several, specific key ideas associated with it which you need to know in order to answer this question (give three examples).
4. a) How did specific Shinto beliefs and attitudes impact or relate to characteristics of Japanese design? Give several examples, citing specific works, or at least types, of design.
b) How did the story of the bamboo cutter most directly seem to parallel or relate to Shinto ideas or attitudes?
5. Look at the Chinese Silk Banner in the textbook, and consider the silk robes we examined in class. How does the banner express typically ancient Chinese ideas or attitudes? What main ideas does silk as used in ancient Chinese design seem to most directly relate to, and how? (Clues can be found in what we got from the Emperor-goes-to-the- Moon story.)
6. a) Consider the Japanese Album Leaf calligraphy shown in the textbook and in class; how is it typically Japanese in character, and how does Japanese calligraphy relate to Chinese calligraphy?
b) Comment on how the Enso – like the one you made in your discussion section – could express or embody any of our main ideas about Japanese design.
Note:
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questions
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usual,
so
you
will
need
to
figure
out
how
to
write
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answer
to
some
of
the
questions
and
more
for
others.
To
be
complete
and
specific
enough
to
do
well,
you
will
need
to
plan
and
edit
these
carefully
to
fit
into
the
two-page
format.
Good
luck.
1.
Discuss
the
Nanchan
Temple
as
a
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example
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Protocol for Breeding Drosophila to Teach Homeobox Genetics and the History and Importance of Model Organisms in Research
1. A Drosophila Protocol for Teaching Homeobox Genetics and Homeotic
Mutations
by Robin Dirksen
1
2. Lesson Overview
This protocol is designed to introduce homeotic mutations and homeoboxes genetics in
addition to traditional Mendelian dominant/recessive inheritance. Students will apply
principles of population genetics and statistical analysis to the data they collect on their
own crosses. The lab will hopefully provide them with concepts that will push them to ask
deeper questions about how model organisms, and Drosophila in particular, are used to
study questions about human diseases. The discussion portion will hopefully give
students an understanding of the relevance of model organisms to their own lives.
Fly life cycle and reproduction p. 3
Homeobox and homeotic genetics p. 4
History of homeobox research p. 5
Teacher Preparation p. 11
Student protocol p. 13
Extensions and Glossary p. 24
References p. 26
Timeline
The student portion of the lab takes approximately 30 days and the instructor portion
takes approximately 50 days. The actual classroom time required performing the
experiments, data collection, and analysis can be done in four 90 minute blocks, and
additional time independent of class for students to come in according to their schedules
to attend to the flies. The increased time required by the instructor is to establish a stock
population large enough for the students to have adequate flies for their crosses.
Objectives
Students will-
-apply knowledge to form hypotheses, correctly use equipement and apply lab
techniques.
-evaluate findings based on experimentation and communicate those findings in writing,
both qualitatively and quantitatively.
-discuss the value and motivation of using model organisms in research
-develop a basic understanding of homeobox genetics and developmental regulation in
organisms, and an appreciation for the universality of many genes across organisms
2
3. Background for the Instructor
Classification of the virtuous and splendid Fruit Fly
Domain: Eukarya
Kingdom: Animalia
Phylum: Arthropoda
Class: Insecta
Order: Diptera
Family: Drosophilidae
Genus: Drosophila (dew lover)
species: melanogaster (dark gut)
Drosophila Life Cycle and Reproduction
The average life span of a Lab fly is 26 days for a female, and 33 days for a male. (Under
crowded conditions this may be reduced to 12 days. Also mutant flies generally have a
shorter life span.) There are four phases to the life cycle: egg, 3 larval (instar) stages,
pupa, and adult. The timing of development is highly influenced by temperature: 10 days
from egg to adult at room temperature (25°C); 13 days at 20°C; 90 days at 15°C.
3
4. Flies may mate more than one once, and fertilized eggs are laid generally after the third
day of the female’s adult life, the eggs are .5 mm long. Larvae hatch out in 22 hours, and
grow and feed for four days, (longer at lower temperatures). The larvae are transparent,
and during the third instar stage of larval development, larvae can be seen crawling up the
sides of the culture container in preparation for pupation. At 25°C the pupa stage lasts
about 4 days. At this time one can see dark projections called pupal horns, off the
anterior end. These are the spiracles (outside opening of the respiratory tubes) turned
inside out. (It is important to notice this when doing salivary gland extraction activities,
because this procedure is best done during the third instar, but before the appearance of
pupal horns.)
The pupal case forms, darkens, and hardens and lasts for 4-6 days, during which time
metamorphosis occurs. Larval tissues are broken down (except for the brain and a few
other tissues), and imaginal discs (pockets of cells stored in the larvae) develop into adult
organs. There is a disc for each leg, wing, eye, antennae etc. The understanding of how
genes act to control the development of imaginal discs, has gotten clearer with continuing
research and has illuminated much about human embryology.
Finally the pupa is ready to eclose (emerge) into the adult stage. At first, before the cuticle
has darkened and hardened, the newly emerged female adult looks pale and puffy. (When
crossing flies of different genotypes, it is important to use virgin females, and this is one
way to visually separate out virgins in a lab population.) Adult Drosophila males and
females can be easily distinguished. Males are smaller, with a rounded, blackened tip to
their abdomen. Females have a pointed abdomen, with a pattern of even dark bands, (see
images).
Homeoboxes and Homeotic Genes
Breeding flies is a great way to teach homeotic and homeobox genetics, the topic may be
better saved as a conclusion to their breeding activities. Let’s start with the definitions-
Homeobox: genes that encode proteins that bind and regulate the expression of DNA in
multicellular organisms. Genes containing homeoboxes are present in the genomes of
many organisms from fruit flies to humans i.e., all eukaryotic genomes, and are associated
with cell differentiation and bodily segmentation. Homeoboxes are DNA sequences
containing about 180 nucleotides that encode for corresponding sequences of usually 60
amino acids, called homeodomains, found in proteins that bind DNA and regulate gene
transcription, determining when those particular groups of genes are expressed.
Homeotic: any of a family of genes that results in a significant change in the embryonic
development of a body part that is homologous to one usually found elsewhere.
Mutations (defining genes) with a phenotype in which a given cell develops along a
4
5. pathway normally followed by a different cell type that can change the fate of an imaginal
disk in insect development.
Homeoboxes are about regulation, or timing of patterns of development in animals, fungi
and plants (genes that are mostly transcription regulators). Homeotic means that
something has been changed into the likeness of something else and homeotic genes can
be thought of as genetic switches that turn different programs of cellular differentiation
on or off.
In summary, homeotic genes encode transcription factors that control the expression of
genes responsible for particular anatomical structures, such as wings, legs, and antennae.
The homeotic genes include a 180 nucleotide sequence called the homeobox, which is
translated into a 60 amino acid domain, called the homeodomain. The homeodomain is
involved in DNA binding, as shown in the images below.
History
A group of mutations called homeotic genes were first discovered In the 1920’s.
However, it was not until 10-20 years later in the 1940’s at Cold Spring Harbor with the
beginnings of molecular biology, that scientists began to understand the structure of
homeotic genes. In the late 40’s and 50’ Edward B. Lewis revealed that regulatory genes
control the body plan of the fly, segment by segment. Lewis found colinearity in time and
space between the order of the genes in the bithorax complex and their affected regions
in the segments.
Christiane Nüsslein-Volhard and Eric F. Wieschaus identified and classified 15 genes of key
importance that controlled the development of the embryo. Their approach was to create
mutations at random then screen large numbers of flies for recessive lethals affecting
5
6. various stages of early embryogenesis. They established 27,000 lines containing mutated
chromosomes and characterized 139 mutations affecting embryogenesis. The original 15
genes were: cubitus interruptus, wingless, gooseberry, hedgehog, fused, patch, paired,
even-skipped, odd-skipped, barrel, runt, engrailed, Kruppel, knirps, and hunchback.
Christiane Nüsslein-Volhard, Eric F. Wieschaus and Edward B. Lewis were awarded the
Nobel Prize in Physiology or Medicine in 1995. This earlier work led to the eventual
sequencing and cloning of these genes in the 1970’s.
Edward B. Lewis at Caltech
Through the years it has been found that homeotic mutations were not caused by one
gene, but by a complex of several genes that are very close to each other on the
chromosome (so much so that crossing over doesn’t happen). They encode transcription
factors which switch on cascades of other genes. Humans have many Hox genes located
on chromosomes 7, 17, 12 and 2.
For example, HoxA and HoxD genes specify segment identitiy along the limb axis. They
are typically found in an organized cluster and the order of the genes in the cluster
correlates to the order of the regions they affect and the timing in which they are
affected. As a consequence, mutations in the cluster result in changes in the affected
regions. When one gene is lost, the segment becomes more anterior, and a gain becomes
more posterior. Mutations to homeobox genes can produce easily visible phenotypes.
The apterous mutation is controlled by another family of homeoboxes called LIM.
6
7. The homeodomain protein motif is highly conserved across vast evolutionary distances.
The functional equivalence of homeotic proteins can be demonstrated by the fact that a
fly can function perfectly well with a chicken homeotic protein in place of its own. This
means that, despite having a last common ancestor that lived over 670 million years ago,
a given homeotic protein in chickens and that in flies are so similar, that they can actually
take each other's place.
Drosophila’s Contribution in Researching Human Disease is Undeniable
The sequencing of the Drosophila genome provides an unparalleled opportunity to
compare human disease gene counterparts in the fly genome. Approximately, 178 out of
287 human disease genes (62%) appear to be conserved in the fly. Drosophila maintains
human paralogs for neurological, hematological, endocrine, renal and immune diseases,
as well as genes for cancer and malformation and metabolic syndromes.
7
8. This next image is a ClustalW alignment of the human and Drosophila Menin proteins.
The fly protein is 34% identical and 47% similar to the human protein over its entire
length. Mutations in menin are found in a familial endocrine cancer characterized by
varying combinations of tumors in the parathyroid glands, the pancreatic islets, the
anterior pituitary, as well as a variety of other tissues. This is just one example of the
orthologs shared between humans and Drosophila.
8
10. Antennepedia is a famous example of homeotic genetics and is one of the mutations the
students will be working with. Antennapedia activates Ubx (Ultrabithorax), Hox protein
genes that specify the structures of the 2nd thoracic segment, which contains a leg and a
wing, and represses genes involved in eye and antenna formation. Thus, legs and wings,
but not eyes and antennae, will form wherever the Antennapedia protein is located. This
mutation is located on chromosome 3, position 47.5. Ubx influences midgut, central
nervous system, peripheral nervous system, leg, and haltere development.
The other mutation the students will work with is apterous, a homeobox gene that with a
recessive mutation, results in flies with either no wings (apt), or vestigial wings (vv). It is
interesting because the organization of the dorsal and ventral compartments of the wing
involves complex signaling pathways and cells in the dorsal compartment express the
homeobox gene apterous (apt), while the ventral compartment cells do not; hence
marking the dorsal/ventral boundary. It is a gene that encodes a protein of the LIM
homeodomain family.
Many transcription factors of this class have been conserved during evolution; however,
the functional significance of their structural conservation is generally not known. ap is
best known for its fundamental role as a dorsal selector gene required for patterning and
growth of the wing, but it also has other important functions required for neuronal
fasciculation, fertility, and normal viability. Mouse (mLhx2) and human (hLhx2) ap
orthologs have been isolated, and used in transgenic animals to investigate the
conservation of the ap protein during evolution. It was found that the human protein
LHX2 is able to regulate correctly ap target genes in the fly, causes the same phenotypes
as ap when ectopically produced, and most importantly rescues ap mutant phenotypes as
efficiently as the fly protein. There are also striking similarities in the expression patterns
of the Drosophila and murine genes. Both mLhx2 and ap are expressed in the respective
nerve cords, eyes, olfactory organs, brain, and limbs. These results demonstrate the
conservation of ap protein function across phyla and argue that aspects of its expression
pattern have also been conserved from a common ancestor of insects and vertebrates.
10
11. Instructor Lab Preparation
Subculturing the shipped flies
When flies arrive subculture the flies using the techniques in the student lab so that there
are about 5-10 males and 5-10 females in each new tube. If the shipped tubes have
ample flies an alternative method from the student anesthesia procedure is to prepare
large culture bottles. They can be subcultured without sexing them, it is likely that you will
have pregnant, or reproductively viable females and males in the tubes. The technique is
to gently tap the shipped tube so the flies move, but do not stick, to the bottom of the
tube, quickly remove the foam top, and let them crawl into the larger subculture tube you
have prepared. For stock cultures, larger bottles can be used to house larger populations,
whatever the size, media should be 1/5th to 2/5th the volume of the bottle (see photo on
the following page). Hydrate with an equal volume of water, what I have discovered since
these photos were taken is to hydrate the media at an angle to prevent water from
pooling, and to keep the media from falling down when the bottles are later put in the
incubator on their sides. It also helps to incubate the bottles on their sides with one end
elevated. Media should sit for a few minutes, adding water if necessary. The surface
should be moist with a shiny appearance and there should be no spaces in the media. If
the media is not completely hydrated, robust culture is compromised. Add a few grains of
yeast, but no more to the media. Label them with the date and phenotypes, and
incubate. Also, place the original flies in the incubator and as additional flies eclose they
may also be subcultured. When the stock culture population is large enough for the class,
virgin females must be obtained for the student vials so that when calculating ratios of F1
and F2 offspring recessive traits will accurately be reflected. Females do not mate for
about 8-10 hours after hatching and can be obtained and placed into separate vials.
Enough flies for groups of 2 or 3 to have 10-20 virgin mutants and 10-20 wild males must
be reared. To maintain an ongoing stock, subculture your flies every 10-14 days.
11
13. Virgin Collecting Methods
Removal: remove all flies from the vial, after 8-10 hours collect all females present in the
original vial and place in a fresh vial and wait 2-3 days to ensure no larvae are present.
(Females tend to eclose early in the morning.)
Visual: virgin females are much larger than older females and are lightly pigmented, a
dark green spot may be visible un the underside of the abdomen (their most recent meal).
Temperature cycling (not tried by this author): cultures at 18°C slow development and the
female will not mate until 16 hours after eclosure. Removing flies in the
afternoon/evening and placing the vials in an 18°C incubator produces about 98%
females.
Make equipment available for students in a dedicated location: students will need a
place where they can get supplies and do their work at their convenience when they need
to as their schedules allow. You will need to provide a morgue for spent flies which can
be a bottle with mineral oil or alcohol. You can use water if you dispose of them daily.
except for anaesthesia: put anaesthesia into a dropper bottle/s and provide it only when
it is to be used by the students. It can potentially be “huffed” and therefore needs to be
controlled by the instructor.
What to do with spent tubes: if plastic tubes are used it is best to dispose of them after
they are used because of the contagious nature of mites and fungi. Plastic can be
autoclaved (20 minutes and 121°C and 15 psi) or washed in a 10% bleach solution,
however both methods make the tubes opaque, which makes it difficult to see into the
tube. Tubes can be placed in the freezer to kill flies and thrown away. If they are glass
dispose of the flies and media, rinse and autoclave or bleach.
Culture Notes:
Although flies can tolerate 25°C (77°F), that is sort of a high end for them, and 20°C (68°F)
is the lower end. I set my incubator at 22°C to be safe, sometimes the inside of the tube
may be slighter warmer than the incubator from the fermentation of the medium. Lower
temperatures prolong the life cycle, higher temperatures increase sterility and reduce
viability. When getting your incubator to temp. keep in mind that if it’s digital it can take
several hours to stabilize. Flies should not be kept in direct sunlight.
This author also learned that using rubber bungs is most definitely not a good idea. While
it ensures that no flies will escape, it does ensure suffocation, which luckily did not
happen, but the epiphany did wake me up in the middle of the night.
13
14. Fly Wrangling 101 How to Subculture and Breed Your Flies
Objectives
• Develop fly handling skills and culture techniques
• Apply computational methods for analyzing data
• Reinforce student understanding of Mendelian genetics
Materials
• Drosophila food medium
• Lg. glass cuvettes
• Clipboard and task/date/name sheet
• Lab Notebook for each group
• Sterile cotton
• Horsehair brushes
• Filter paper (should be the appropriate size to fit inside a Petri dish, as well as
strips for anaesthesia) or white index cards
• Dissecting scope
• Petri dishes (also preferably glass)
• Funnel
• Anesthesia (there are several brands readily available in catalogs)
• Nets for tubes (or filter paper)
• Incubator for holding constant temperature if possible
Procedure
1. Prepare two culture tubes for your crosses. Make sure that your label includes:
• the generation, e.g. P for parents (this will be your first generation that you’ve
placed into your new tubes), F1, F2, etc. for subsequent offspring.
• the date
• the type of mating in the cross
2. The amount of media used depends on the culture tube. In a standard tube use about
10 mls of dry media and equal parts water. If you’re using a glass cuvette use 5 mls of
media and equal parts water. You will want the media to remain at the bottom of the
vial, avoid chunks of media on the sides of the tube. Simply pour the water into the tube,
give it a few minutes to soak into the media. If the media is still dry you may add a bit
more water, (the larvae prefer the media on the wet side, rather than too dry).
3. Put a piece of filter paper in your Petri dish, and tape a strip of filter paper to the inside
of the lid. (In case your flies wake-up before you’re done with them you can put a drop of
anaesthesia on the paper taped to the lid.)
14
15. 4. Obtain vials of parental flies from your teacher.
5. Record the vial number and parental cross marked on the vial in your notebook and
start your datasheets. When working with your flies have your notebook and your
datasheets with you.
6. Put a couple of drops of Fly Nap on the cotton at the bottom of the sleep box. (A
cotton swab can also be inserted in the tube with the flies instead of using a sleep box).
Open the sleep box and put your fly tubes in the box, put the lid on the box, open the lid
on with as little an opening as possible and using forceps, take the cotton swabs out of
your parent tubes. It is important to keep your tubes on their sides as much as possible
when handling flies that are asleep. If not the flies will fall into the wet medium, adhere
to the medium and drown.
When the flies STOP MOVING (usually ~ 2 min.) they are sufficiently anaesthetized, they
will die if left in the anaesthesia too long, (when the wings stand out at an angle, the flies
are dead). Gently dump the flies into the viewing dish and observe and record the
phenotypes and sexes of the flies (it is difficult to look for banding in newly hatched flies
as the pigments are not well developed). IF YOUR FLIES START WAKING UP PUT A COUPLE
OF DROPS OF ANAESTHESIA ON THE FILTER PAPER TAPED TO THE LID OF A PETRI DISH
AND COVER YOUR FLIES. In your journal describe eye color, number and size of wings, or
any unusual placement of body structures.
7. Place a five or six wild males and a five or six mutant females into each of your culture
tubes, keeping your tubes on their sides using your paintbrush, and put your tubes into
the incubator.
8. After seven days remove the parent flies from the mating bottle by tapping them into
the sleep box and anesthetizing them until dead. Put them into a Petri and look at them
under the dissecting scope, in your notebook draw (feel free to use colored pencils) a
male, a female and a mutant, label the drawing (wild or mutant, male and female). Also,
label the parts of the body (insects have a head, a thorax and an abdomen). When you
are finished with your drawing discard flies into the morgue and place tubes back in the
incubator. Record what you did and the date in your notebook.
9. When the flies begin to emerge, examine them and record the characteristics. This is
the F1 generation. If the mutation is recessive, none of the F1 should exhibit the mutation.
If any do, one of the P females was not a virgin and the culture should not be used in the
rest of the experiment. Go back to step 1.
10. Prepare two or three new culture bottles, (properly labeled). Place 5-6 F1 males and
females into two or three culture bottles and place in the incubator.
15
16. After 7 days euthanize the F1 flies and discard them.
When the F2 generation eclose euthanize them and record phenotypes
Before turning in your journal make sure it contains: a drawing and description of wild
male, female, and mutant flies, and a drawing of the life cycle of Drosophila. At the end of
your journal, pose at least three questions you would like to investigate.
16
17. Identifying Flies
Female on the left has an elongated posterior with thinner pigment bands, male on the
right, the abdomen of the male has a black tip and a more round posterior
Male on the left, (note the sex combs on the forelegs) female on the right
17
18. Our mutations
1. Antennepedia (that means legs on yer noggin, or legheadedness) it’s a _ mutation,
Here’s the homeodomain antennepedia protein
18
19. 2. and the last one on the right, Apterous (missing wings, oops), with some other
mutated-winged friends.
19
20. Collecting Data
1. About 7 days after starting cross, remove parents to prevent breeding between
generations and to insure data collection from one generation only.
2. Data collection from an experimental cross is begun the day after the progeny first
emerge. Usually flies are phenotyped and counted every other day for about 8 days to
insure inclusion of mutants and the sex with slower developmental rates (females often
appear sooner than males).
Genetic Notation Used in Describing Crosses
A fly with red eyes and other normal traits is called wild type and is designated by a +.
The + refers here to all the traits (the entire phenotype). However, a + can also refer to an
allele (locus).
A fly with a heritable trait different from wild type is considered a mutant. Mutations at
particular loci are designated by letters derived from the descriptive name of the
mutation. Abbreviations for recessive mutations are written entirely in lower case letters,
whereas abbreviations for dominant mutations begin with capital letters. For our flies, we
will use the symbols +,+ for the wild fly to indicate that wild alleles are dominant and a,a
for the apterous fly indicating that the apterous allele genotype is recessive.
(During the initial stages of an inheritance study when the dominance relationships of
alleles are unknown, the problem of deciding how to abbreviate the name for the
mutation can be avoided by using a combination of letters and superscripts to designate a
particular allele. For example, a mutant autosomal trait can be denoted as Am, while its
wildtype counterpart can be denoted as A+. Similarly, an X-linked trait can be denoted as
Xm for the mutant allele, and X+ for the wild type allele.)
20
21. Datasheet
Make a prediction about the genotypes and phenotypes of your P, F1 and F2 generations
assuming the mutation is recessive.
Make a prediction about the genotypes and phenotypes of your P, F1 and F2 generations
assuming the mutation is dominant.
P
Date Number of Males and Number of Females and
Phenotypes Phenotypes
Name/s of team member/s doing the cross today:______________________
Comments:
F1
Date Number of Phenotype 1 Number of Phenotype 2
Name/s team member/s doing the cross today:______________________
Comments:
F2
Date Number of Phenotype 1 Number of Phenotype 2
Name/s team member/s doing the cross today:______________________
Comments:
21
22. Analysis
Hardy-Weinberg
The Hardy-Weinberg equation will allow you to estimate the approximate percentages
and gene frequencies of homozygous dominant, heterozygous and recessive genotypes
of your flies.
The equation is p2 + 2pq + q2, where p2 will represent the homozygous dominant
genotype, q2 will represent the recessive genotype and 2pq will represent the
heterozygous individuals.
Here’s an example of how your will use the equation:
Total fly population- 278
Number of wilds- 190 (these show the dominant phenotype)
Number of mutants- 88 (the recessive phenotype)
The percent of each :
Dominant – (p2 + 2pq ) 190/278 x 100% = 68.35%, as a frequency .6835
Recessive- (q2 ) 88/278 x 100% = 31.66%, as a frequency .3166, q = .563
In order to find the frequency of heterozygotes we have to find p.
p = 1-q, p = 1 - .563 = .437
p2 = .191
2pq = 2(.437)(.563)
To estimate the number of homozygous flies, multiply the frequency of p2 by the total
population.
278(.191) = 53.09, or 53
the estimated number of heterozygous individuals, multiply the frequency of 2pq by the
total population
278(.492) = 136.8, or 137
find the expected number of recessives by multiplying the total population by .25
278 x .25 = 69.5
Now that you know the observed and expected we can use something called a Chi-square,
which will let us evaluate the dataset.
The chi-square test is used in two similar but distinct circumstances:
22
23. a. for estimating how closely an observed distribution matches an expected
distribution - we'll refer to this as the goodness-of-fit test
b. for estimating whether two random variables are independent.
Chi Square
Χ2 = ∑ (observed x frequency – expected x frequency)2
expected x frequency
The funny x looking thing is just the Greek letter “chi.” The expected is other Greek letter,
sigma, which in statistics means “sum.”
Lastly, to determine the significance level we need to know the quot;degrees of freedom.quot; In
the case of the chi-square goodness-of-fit test, the number of degrees of freedom is equal
to the number of terms used in calculating chi-square minus one. There were two terms in
the chi-square for this problem - therefore, the number of degrees of freedom is one.
df P = 0.05 P = 0.01 P = 0.001
1 3.84 6.64 10.83
2 5.99 9.21 13.82
3 7.82 11.35 16.27
4 9.49 13.28 18.47
5 11.07 15.09 20.52
Report your statistical results in the Results section of your lab report.
23
24. Extensions
• Research function and expression of human Hox genes.
Research of homeobox families and classes
http://homeodb.cbi.pku.edu.cn/families.php?og=Drosophila
• Evolution of homeobox genes
• Evo-devo
• Up-regulation and down-regulation of genes
• Virtual Apterous Lab
Glossary of Terms
imaginal disc: epithelial infoldings in the larvae of holometabolous insects (e.g.
Lepidoptera, Diptera) that rapidly develop into adult appendages (legs, antennae, wings
etc.) during metamorphosis from larval to adult form. During larval development, imaginal
discs grow inside the larva. Development of the adult from the imaginal disc entails
complex signaling interactions that divide the disc into distinct anterior, posterior, dorsal,
and ventral compartments. At metamorphosis, the larva forms a pupa, inside which the
larval tissues are reabsorbed and the imaginal tissues undergo extensive morphogenetic
movements to form adult structures.
homeotic genes: in general homeotics are thought of as genetic switches that control the
choice between different developmental pathways, also known as Hox genes, specifying
the anterior-posterior axis and segment identity during early development of metazoan
organisms. They are critical for the proper placement and number of embryonic segment
structures (such as legs, antennae and eyes). The first genes found to encode
homeodomain proteins were Drosophila developmental control genes, in particular
homeotic genes, from which the name quot;homeoquot;box was derived. However, many
homeobox genes are not homeotic genes; the homeobox is a sequence motif (a
nucleotide or amino-acid sequence pattern that is widespread and has, or is conjectured
to have, a biological significance), while quot;homeoticquot; is a functional description for genes
that cause homeotic transformations.quot;
homeobox: a fragment of DNA of about 180 basepairs (not counting introns), found in
homeobox genes. A homeobox is a DNA sequence found within genes that are involved in
the regulation of patterns of development (morphogenesis) in animals, fungi and plants.
Genes that have a homeobox are called homeobox genes and form the homeobox gene
family. Homeobox genes encode transcription factors which typically switch on cascades
of other genes.
LIM-homeobox genes: The primary structure of LIM-homeobox genes has been
remarkably conserved through evolution. A host of new data has been derived from
24
25. mutational analysis in diverse organisms, such as nematodes, flies and vertebrates. These
studies have revealed a prominent involvement of LIM-homeodomain proteins in tissue
patterning and differentiation, and their function in neural patterning is evident in all
organisms studied to date. LIM genes act in a variety of developmental contexts, and
display functional similarities across all organisms studied All LIM genes have expression
and function in the nervous system (but some act elsewhere too). LIM genes determine
correct axonal arrangements: sensory, motor or inter neurons. LIM genes may share
overlapping functions in distinct cell types, might regulate common sets of downstream
target genes But some LIM genes have quite specific roles: mec-3 regulates touch-
neuron-specific genes (C. elegans),
apterous: wingless, a LIM-homeodomain protein that is expressed in dorsal cells and acts
as a selector gene to divide the disc into dorsal and ventral compartments
homeodomain: in eukaryotes, homeodomains induce cellular differentiation by initiating
the cascades of coregulated genes required to produce individual tissues and organs. The
DNA-binding domain, binds DNA in a specific manner, is usually about 60 amino acids in
length, and is encoded by the homeobox. The homeodomain fold is a protein structural
domain that binds DNA or RNA and is thus commonly found in transcription factors. Most
of the time, homeodomain proteins act in the promoter region of their target genes as
complexes with other transcription factors, often also homeodomain proteins. The fold
consists of a 60-amino acid helix-turn-helix structure in which three alpha helices are
connected by short loop regions [1]. The N-terminal two helices are antiparallel and the
longer C-terminal helix is roughly perpendicular to the axes established by the first two. It
is this third helix that interacts directly with DNA. Homeodomain folds are found
exclusively in eukaryotes but have high homology to lambda phage proteins that alter the
expression of genes in prokaryotes.
Hox genes: Hox genes are a subgroup of homeobox genes. In vertebrates these genes are
found in gene clusters on the chromosomes. In mammals four such clusters exist, called
Hox clusters. The gene name quot;Hoxquot; has been restricted to name Hox cluster genes in
vertebrates. Only genes in the HOX cluster should be named Hox genes. So note:
homeobox genes are NOT Hox genes, Hox genes are a subset of homeobox genes.
Hox cluster: The term Hox cluster refers to a group of clustered homeobox genes, named
Hox genes in vertebrates, that play important roles in pattern formation along the
anterior-posterior body axis. In fact, the first homeobox genes discovered where those of
the Drosophila homeotic gene clusters, i.e. the quot;Antennapedia complexquot; and the
quot;Bithorax complexquot;, which summarily are referred to as HOM-C (homeotic complex). This
HOM-C complex in Drosophila is the evolutionary homolog of the vertebrate Hox clusters
and the evolutionarily related homeobox gene clusters in other animals (i.e. chordates,
insects, nematodes, etc.) are now also called HOX clusters.
25
26. References
Photos of flies http://biol.org/DrosPics.htm
Culturing and life cycle, Pete Geiger, The Biology Project
http://biology.arizona.edu/sciconn/lessons2/geiger/intro2.htm
http://biology.arizona.edu/sciconn/lessons2/geiger/intro.htm
Antennapedia Interactive Fly http://www.sdbonline.org/fly/segment/antenap3.htm
http://www.sdbonline.org/fly/segment/antenap1.htm#Bio
Apterous Virtual Fly Lab http://bioweb.wku.edu/courses/Biol114/Vfly1.asp
Apterous Homeodomain, Marco Milán, et al, European Molecular Biology Laboratory,
http://www.sciencedirect.com/science?
_ob=ArticleURL&_udi=B6T9H-4C2F8SJ-1&_user=10&_rdoc=1&_fmt=&_orig=search&_sort
=d&view=c&_acct=C000050221&_version=1&_urlVersion=0&_userid=10&md5=1f829451
d5bddf51e8e0f6a2508ee546
Homeobox Database Homepage maintained by Thomas R. Bürglin
http://homeodb.cbi.pku.edu.cn/
Homeobox Database Drosophila main page, homeobox by family
http://homeodb.cbi.pku.edu.cn/
Other homeobox information from http://faculty.pnc.edu/pwilkin/homeobox.html
http://www.cbt.ki.se/groups/tbu/homeo.html
Antennapedia Homeobox http://homeodb.cbi.pku.edu.cn/family_info.php?
spf=t&spfm=ANTP&sbfm=&og=All
Hox Genes Department of Biochemistry & Cell Biology Rice University
Journal of Biological Chemistry http://www.jbc.org/cgi/reprint/M312842200v1.pdf
Developmental Regulatory Networks http://www.wwnorton.com/college/biology/devbio/
chaptersummary/ch15.htm
Human-Fly genes that are shared A Survey of Human Disease Gene Counterparts in the
Drosophila Genome, Mark E. Fortini, et al PMCID: PMC2180233 Fig 1. disease genes
shared Fig 2 Blast table, included in protocol
http://www.pubmedcentral.nih.gov/articlerender.fcgi?artid=2180233
26
27. Autism and Hox http://instruct1.cit.cornell.edu/courses/bioap475/Autism
%203_11_02.pdf
Edward Lewis http://www.genetics.org/cgi/reprint/168/4/1773
27