This document provides an overview of sex determination systems in animals. It discusses the main types of sex determination including environmental/non-genetic (influenced by temperature or location), chromosomal (XX-XO, XX-XY, etc.), and genic systems. For chromosomal sex determination, it describes the different mechanisms like XX-XO system found in grasshoppers and XY system common in humans and mice. It also discusses rare systems like haplodiploidy in bees and wasps.
The determination of the sex in an animal is the complex system for deciding the sex of organism. it is depends on the chromosomes present in the animals. some animals determine the sex of an animal by external environmental factors.
Reference
Moeller, Karla T., "Temperature-Dependent Sex Determination in Reptiles". Embryo Project Encyclopedia (2013-02-01). ISSN: 1940-5030
Morjan, Carrie L. 2003. “How Rapidly Can Maternal Behavior Affecting Primary Sex Ratio Evolve in a Reptile with Environmental Sex Determination ?”
Shine, Richard. 1999. “Why Is Sex Determined by Nest Temperature in Many Reptiles?” 14(5): 186–89.
Wapstra, Erik et al. 2006. “Maternal Basking Behavior Determines Offspring Sex in a Viviparous Reptile.” : 230–32.
The determination of the sex in an animal is the complex system for deciding the sex of organism. it is depends on the chromosomes present in the animals. some animals determine the sex of an animal by external environmental factors.
Reference
Moeller, Karla T., "Temperature-Dependent Sex Determination in Reptiles". Embryo Project Encyclopedia (2013-02-01). ISSN: 1940-5030
Morjan, Carrie L. 2003. “How Rapidly Can Maternal Behavior Affecting Primary Sex Ratio Evolve in a Reptile with Environmental Sex Determination ?”
Shine, Richard. 1999. “Why Is Sex Determined by Nest Temperature in Many Reptiles?” 14(5): 186–89.
Wapstra, Erik et al. 2006. “Maternal Basking Behavior Determines Offspring Sex in a Viviparous Reptile.” : 230–32.
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
How 3 germ layers are formed in Chick that are endoderm, mesoderm and ectoderm.As Chick are polylecithal so cell movements are somewhat restricted and gastrulation is modified as compared to frog.
Sex Determination definition.
Chromosomal Sex Determination.
Primary sex determination.
Secondary Sex determination.
Genetic mechanism.
Environmental Sex Determination.
Conclusion.
Introduction :
Mendel and subsequent workers assumed that a character was governed by a single gene.
But it was later discovered that many characters in almost all the organisms are governed by two or more genes. Such gene affect the development of concerned characters in various ways.
The phenomenon of two or more gene affecting the expression of each other in various ways in the development of a single character of on organism is known as gene interaction.
Variation-Genetic variation is the difference in DNA sequences between individuals within a population. Variation occurs in germ cells i.e. sperm and egg, and also in somatic (all other) cells. Only variation that arises in germ cells can be inherited from one individual to another and so affect population dynamics, and ultimately evolution.
Basics of Undergraduate/university fellows
Nucleosome model of chromosome is proposed by ROGER KORNBERG (son of Arthur
Kornberg) in 1974.
It was confirmed and crystalised by P. Oudet et al., (1975).
Nucleosome is the lowest level of Chromosome organization in eukaryotic cells.
Nucleosome model is a scientific model which explains the organization of DNA and
associated proteins in the chromosomes.
Nucleosome model also explains the exact mechanism of the folding of DNA in
thenucleus.
It is the most accepted model of chromatin organization.
A cytological technique to detect the nature of adjacent chromosomal regions by using different staining technique assisted with some pre treatment of metaphase chromosomes prepared on the slides
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
How 3 germ layers are formed in Chick that are endoderm, mesoderm and ectoderm.As Chick are polylecithal so cell movements are somewhat restricted and gastrulation is modified as compared to frog.
Sex Determination definition.
Chromosomal Sex Determination.
Primary sex determination.
Secondary Sex determination.
Genetic mechanism.
Environmental Sex Determination.
Conclusion.
Introduction :
Mendel and subsequent workers assumed that a character was governed by a single gene.
But it was later discovered that many characters in almost all the organisms are governed by two or more genes. Such gene affect the development of concerned characters in various ways.
The phenomenon of two or more gene affecting the expression of each other in various ways in the development of a single character of on organism is known as gene interaction.
Variation-Genetic variation is the difference in DNA sequences between individuals within a population. Variation occurs in germ cells i.e. sperm and egg, and also in somatic (all other) cells. Only variation that arises in germ cells can be inherited from one individual to another and so affect population dynamics, and ultimately evolution.
Basics of Undergraduate/university fellows
Nucleosome model of chromosome is proposed by ROGER KORNBERG (son of Arthur
Kornberg) in 1974.
It was confirmed and crystalised by P. Oudet et al., (1975).
Nucleosome is the lowest level of Chromosome organization in eukaryotic cells.
Nucleosome model is a scientific model which explains the organization of DNA and
associated proteins in the chromosomes.
Nucleosome model also explains the exact mechanism of the folding of DNA in
thenucleus.
It is the most accepted model of chromatin organization.
A cytological technique to detect the nature of adjacent chromosomal regions by using different staining technique assisted with some pre treatment of metaphase chromosomes prepared on the slides
Sex determination is important to distinguish an organism as male, female and hermaphrodite. XX-XO sex determination is one type of determination which is found in plants and insects
The increased availability of biomedical data, particularly in the public domain, offers the opportunity to better understand human health and to develop effective therapeutics for a wide range of unmet medical needs. However, data scientists remain stymied by the fact that data remain hard to find and to productively reuse because data and their metadata i) are wholly inaccessible, ii) are in non-standard or incompatible representations, iii) do not conform to community standards, and iv) have unclear or highly restricted terms and conditions that preclude legitimate reuse. These limitations require a rethink on data can be made machine and AI-ready - the key motivation behind the FAIR Guiding Principles. Concurrently, while recent efforts have explored the use of deep learning to fuse disparate data into predictive models for a wide range of biomedical applications, these models often fail even when the correct answer is already known, and fail to explain individual predictions in terms that data scientists can appreciate. These limitations suggest that new methods to produce practical artificial intelligence are still needed.
In this talk, I will discuss our work in (1) building an integrative knowledge infrastructure to prepare FAIR and "AI-ready" data and services along with (2) neurosymbolic AI methods to improve the quality of predictions and to generate plausible explanations. Attention is given to standards, platforms, and methods to wrangle knowledge into simple, but effective semantic and latent representations, and to make these available into standards-compliant and discoverable interfaces that can be used in model building, validation, and explanation. Our work, and those of others in the field, creates a baseline for building trustworthy and easy to deploy AI models in biomedicine.
Bio
Dr. Michel Dumontier is the Distinguished Professor of Data Science at Maastricht University, founder and executive director of the Institute of Data Science, and co-founder of the FAIR (Findable, Accessible, Interoperable and Reusable) data principles. His research explores socio-technological approaches for responsible discovery science, which includes collaborative multi-modal knowledge graphs, privacy-preserving distributed data mining, and AI methods for drug discovery and personalized medicine. His work is supported through the Dutch National Research Agenda, the Netherlands Organisation for Scientific Research, Horizon Europe, the European Open Science Cloud, the US National Institutes of Health, and a Marie-Curie Innovative Training Network. He is the editor-in-chief for the journal Data Science and is internationally recognized for his contributions in bioinformatics, biomedical informatics, and semantic technologies including ontologies and linked data.
Cancer cell metabolism: special Reference to Lactate PathwayAADYARAJPANDEY1
Normal Cell Metabolism:
Cellular respiration describes the series of steps that cells use to break down sugar and other chemicals to get the energy we need to function.
Energy is stored in the bonds of glucose and when glucose is broken down, much of that energy is released.
Cell utilize energy in the form of ATP.
The first step of respiration is called glycolysis. In a series of steps, glycolysis breaks glucose into two smaller molecules - a chemical called pyruvate. A small amount of ATP is formed during this process.
Most healthy cells continue the breakdown in a second process, called the Kreb's cycle. The Kreb's cycle allows cells to “burn” the pyruvates made in glycolysis to get more ATP.
The last step in the breakdown of glucose is called oxidative phosphorylation (Ox-Phos).
It takes place in specialized cell structures called mitochondria. This process produces a large amount of ATP. Importantly, cells need oxygen to complete oxidative phosphorylation.
If a cell completes only glycolysis, only 2 molecules of ATP are made per glucose. However, if the cell completes the entire respiration process (glycolysis - Kreb's - oxidative phosphorylation), about 36 molecules of ATP are created, giving it much more energy to use.
IN CANCER CELL:
Unlike healthy cells that "burn" the entire molecule of sugar to capture a large amount of energy as ATP, cancer cells are wasteful.
Cancer cells only partially break down sugar molecules. They overuse the first step of respiration, glycolysis. They frequently do not complete the second step, oxidative phosphorylation.
This results in only 2 molecules of ATP per each glucose molecule instead of the 36 or so ATPs healthy cells gain. As a result, cancer cells need to use a lot more sugar molecules to get enough energy to survive.
Unlike healthy cells that "burn" the entire molecule of sugar to capture a large amount of energy as ATP, cancer cells are wasteful.
Cancer cells only partially break down sugar molecules. They overuse the first step of respiration, glycolysis. They frequently do not complete the second step, oxidative phosphorylation.
This results in only 2 molecules of ATP per each glucose molecule instead of the 36 or so ATPs healthy cells gain. As a result, cancer cells need to use a lot more sugar molecules to get enough energy to survive.
introduction to WARBERG PHENOMENA:
WARBURG EFFECT Usually, cancer cells are highly glycolytic (glucose addiction) and take up more glucose than do normal cells from outside.
Otto Heinrich Warburg (; 8 October 1883 – 1 August 1970) In 1931 was awarded the Nobel Prize in Physiology for his "discovery of the nature and mode of action of the respiratory enzyme.
WARNBURG EFFECT : cancer cells under aerobic (well-oxygenated) conditions to metabolize glucose to lactate (aerobic glycolysis) is known as the Warburg effect. Warburg made the observation that tumor slices consume glucose and secrete lactate at a higher rate than normal tissues.
Professional air quality monitoring systems provide immediate, on-site data for analysis, compliance, and decision-making.
Monitor common gases, weather parameters, particulates.
Slide 1: Title Slide
Extrachromosomal Inheritance
Slide 2: Introduction to Extrachromosomal Inheritance
Definition: Extrachromosomal inheritance refers to the transmission of genetic material that is not found within the nucleus.
Key Components: Involves genes located in mitochondria, chloroplasts, and plasmids.
Slide 3: Mitochondrial Inheritance
Mitochondria: Organelles responsible for energy production.
Mitochondrial DNA (mtDNA): Circular DNA molecule found in mitochondria.
Inheritance Pattern: Maternally inherited, meaning it is passed from mothers to all their offspring.
Diseases: Examples include Leber’s hereditary optic neuropathy (LHON) and mitochondrial myopathy.
Slide 4: Chloroplast Inheritance
Chloroplasts: Organelles responsible for photosynthesis in plants.
Chloroplast DNA (cpDNA): Circular DNA molecule found in chloroplasts.
Inheritance Pattern: Often maternally inherited in most plants, but can vary in some species.
Examples: Variegation in plants, where leaf color patterns are determined by chloroplast DNA.
Slide 5: Plasmid Inheritance
Plasmids: Small, circular DNA molecules found in bacteria and some eukaryotes.
Features: Can carry antibiotic resistance genes and can be transferred between cells through processes like conjugation.
Significance: Important in biotechnology for gene cloning and genetic engineering.
Slide 6: Mechanisms of Extrachromosomal Inheritance
Non-Mendelian Patterns: Do not follow Mendel’s laws of inheritance.
Cytoplasmic Segregation: During cell division, organelles like mitochondria and chloroplasts are randomly distributed to daughter cells.
Heteroplasmy: Presence of more than one type of organellar genome within a cell, leading to variation in expression.
Slide 7: Examples of Extrachromosomal Inheritance
Four O’clock Plant (Mirabilis jalapa): Shows variegated leaves due to different cpDNA in leaf cells.
Petite Mutants in Yeast: Result from mutations in mitochondrial DNA affecting respiration.
Slide 8: Importance of Extrachromosomal Inheritance
Evolution: Provides insight into the evolution of eukaryotic cells.
Medicine: Understanding mitochondrial inheritance helps in diagnosing and treating mitochondrial diseases.
Agriculture: Chloroplast inheritance can be used in plant breeding and genetic modification.
Slide 9: Recent Research and Advances
Gene Editing: Techniques like CRISPR-Cas9 are being used to edit mitochondrial and chloroplast DNA.
Therapies: Development of mitochondrial replacement therapy (MRT) for preventing mitochondrial diseases.
Slide 10: Conclusion
Summary: Extrachromosomal inheritance involves the transmission of genetic material outside the nucleus and plays a crucial role in genetics, medicine, and biotechnology.
Future Directions: Continued research and technological advancements hold promise for new treatments and applications.
Slide 11: Questions and Discussion
Invite Audience: Open the floor for any questions or further discussion on the topic.
2. INTRODUCTION
• Sex determination system is a biological system
that determines the development of sexual
characteristics in an organism.
• Most organisms that create offspring using
sexual reproduction have two sexes.
• There are hermaphrodites in place of one or
both sexes.
• There are also some species that have only one
sex due to parthenogenesis (female
reproducing without fertilization.)
3. HISTORY
• 1891 – H.Henking
While studying spermatogenesis
of wasp noted a particular
nuclear structure. Half of the
sperm receives this structure &
half didnot. He didnot speculate
on the significance of this body
but called it “X-body”. First
experimental evidence that led
to discovery of sex
chromosomes.
4. • 1902 – C. E. McClung
Made extensive observations
of spermatogenesis in
Grasshopper & suggested that
“X-body was involved in
determination of sex”. He
reported that somatic cells of
female grasshopper contains
24 chromosomes & male have
23 chromosomes.
5. • 1905 – E. B. Wilson & N. Stevens
Noted that females of Protenor
have 7 pairs of chromosome & male
have 6 & an unpaired chromosome.
They called it X – chromosome.
• 1908 – Discovered Y chromosome
and so named by Stevens.
6. SEX DETERMINATION
• Establishment of male and female individuals or
male and female organs of an individual is called
sex determination.
• Mechanism of sex determination-3 types
Environmental
Chromosomal
Genic
7. • Zygotes do not differ genetically.
• Sex differentiation determined by environmental
factors.
• 2 types
Temperature dependent
Location dependent
1. ENVIRONMENTAL / NON-
GENETIC SEX DETERMINATION
8. 1. Temperature-dependent sex
determination
In some animals (turtles, alligators, crocodiles,
some lizards etc.) the temperature at which eggs
are incubated has a decisive effect on sex of
animals that hatch from them. These effects are
of 3 types:
• Only females at high (30-35°C) and only males
at low (23-28°C). Incubation of eggs at
intermediate temperatures(28-30°C) produce
both males and females.
Eg: most species of turtles
9. • Only males at high(>33°C) and only females at
low(<30°C) temperatures. Intermediate
temperatures(30-33°C) produces both males and
females
Eg: many species of crocodiles and alligators and
in some species of lizards
• Only females at high(30-35°C) and low(<25°C)
temperatures. At intermediate temperatures,
both males and females are produced, but at
some intermediate temperatures, only males are
produced.
Eg: Australian crocodile, snapping turtles
10. 2. Location-dependent sex
determination
Eg: Bonellia viridis – marine
(green spoon worm)
• ♂ and ♀ have same chromosomes.
• If a young worm is raised from an
isolated larva it becomes a female.
• If larva comes in contact with female
then larva turns into male and
eventually migrates to female
reproductive tract.
• Possibly a hormone is secreted from
the proboscis of female to initiate
male sexual differentiation.
11. 2. CHROMOSOMAL SEX
DETERMINATION
• Male and female individuals differ from each
other in respect to either the number or
morphology of the homologues of one
chromosome pair, referred to as sex
chromosome or allosome – X & Y
• X chromosome found in both males(only one)
and females(has two X chr.)
• Y chromosome occurs only in one of two sexes
of a species.
• Chromosomes whose number and morphology
do not differ between males and females of a
species are called autosomes.
12. Mechanisms of chromosomal sex determination:
1. XX-XO system [XX female, XO male
XO female, XX male]
2. XX-XY system [XX female, XY male
XY female, XX male]
3. ZZ-ZW system
4. Haplodiploidy system [Diploid (2n) female,
Haploid (n) male]
13. XX FEMALE, XO MALE
• Females possess two X- chromosomes (XX) -
homogametic females.
• Males possess only one X-chromosome -
heterogametic males.
• O or zero in XO chromosome →absence of
another X- chromosome.
• Found in grasshoppers, Protenor and many other
insects, esp. those belonging to Orthoptera.
14. • If X carrying ovum fertilized
by X carrying sperm -zygote
develop into a female.
• If sperm containing no
chromosome unites with
ovum -zygote formed is XO-
develop into male.
• Maternal gametes always
contain an X chromosome -
sex of offspring depends on
whether a sex chromosome
is present in male gamete.
15. XO FEMALE, XX MALE
• Known in a few insect species, e.g., Fumea
• Females are heterogametic (producing two kinds
of eggs, half with a X chromosome and half
without any X chromosome) and males are
homogametic (producing single type of sperms,
each carrying a single X chromosome).
• Union of a sperm with X chromosome containing
egg -XX zygote -males.
• Fertilization of an egg devoid of X chromosome
with a sperm -XO zygote -females.
16. XX FEMALE, XY MALE
• Most common among animals
• Found in humans, mice,
Diptera(Drosophila, house fly,
etc.), some fishes, some
amphibia, etc.
• Females are homogametic (XX)
produce one kind of eggs, each
with one X chromosome.
• Males are heterogametic (XY)
produce two kinds of sperms :
half with X chromosome and half
with Y chromosome.
17. • Fertilization of egg by a
sperm having X
chromosome -XX zygote-
female.
• Union of egg with sperm
having Y chromosome -XY
zygote -males.
18. XY FEMALE, XX MALE
• Found in birds, reptiles, some
insects, e.g., silk worm, etc.
• Females have XY chromosome
constitution - heterogametic sex -
half the eggs have X, rest have Y
chromosome.
• Males have two X chromosomes
(XX) homogametic sex -all sperms
have one X chromosome.
19. • Fertilization of X containing egg with sperm -XX
zygote-male.
• XY zygote -when Y containing egg is fertilized by
a sperm-female.
20. ZW FEMALE, ZZ MALE
• Occur in certain insects & vertebrates like
amphibians, reptiles, birds & plants
• Female have one Z and one W chromosome-
produce two types eggs.
• Male - two homomorphic Z chromosomes.
21. • Sex of offsprings depends upon the
kind of egg
• Z bearing egg produce male & W
bearing egg produce female.
22. • Found in Hymenoptera(honeybees, ants, termites,
etc)
• An individual’s sex determined by number of sets
of chromosomes.
• First demonstrated by Dzierzon in 1850
• Somatic chromosome no. of females is diploid,
males is only haploid
• When an egg is fertilized by a sperm, the
developed organism will be diploid (2n)- female
• If egg is not fertilized, organism is haploid(n) -
male.
DIPLOID FEMALE, HAPLOID MALE
23. • During spermatogenesis, males
produce haploid sperms
• Normal meiosis during oogenesis
produces all haploid eggs
• Fertilization of eggs produces
diploid zygotes - develop into
diploid larvae - give rise to
workers which are sterile
females
• Diploid larvae fed on royal jelly
develop into fertile females
called queen
• Unfertilized eggs develop
parthenogenically - produce
haploid larvae - fully fertile
haploid males called drones
24. • Some specific genes located in X and Y
chromosomes are involved in sex determination.
• Explained by Genic balance theory of sex
determination in Drosophila proposed by Bridges
in 1921.
• Theory states that sex of an individual is
determined by a balance between the genes for
maleness and those for femaleness present in
the individual
• In Drosophila, genes for maleness are present in
autosomes and those of femaleness are located
in X chromosome
3. GENIC SEX DETERMINATION
25. • ie, sex of an individual is determined by the ratio
of no. of its X chromosome and that of its
autosomal sets, termed as sex index
Sex index = Number of X chromosomes(=X) = X/A
Number of autosomal sets (=A)
• Sex index = 1 normal females
= 0.5 normal males
= 1.0 – 0.5 intersex
= > 1.0 super females/meta females
= < 0.5 super males
26. GYNANDROMORPHS
• Individuals showing male characteristics
in a part of their body and remaining
parts show female phenotype
• In Drosophila gynandromorphs are
always mosaics for X chromosome;
parts with male phenotype are
always XO and female phenotype
are XX
• They arise from XX zygotes.
Editor's Notes
Intersex – flies with sex expression (both primary and secondary sex characters) intermediate b/w males and females & completely sterile
Super females- more pronounced female characteristics than normal females-weak, sterile and often inviable
Supermales- more pronounced secondary sex characters then normal males-weak, sterile and inviable
During embryonic developement in one or more cells one of the two X chromosomes does not pass away at anaphase and as a result is lost. Consequently one or more daughter cells having a single X chromosome are produced, these cells divide and give rise to male parts of gynandromorphs.
