All human beings, no matter how different we look, have a certain basic body plan established in us (for instance, all of us have our heads are placed right above our shoulders with arms stretching out from either side). Drosophila is no exception. This presentation talks about establishment of the body plan in Drosophila, how and when the different Segmentation Genes are expressed in Drosophila to give rise to its segmented body pattern.
INTRODUCTION
DEFINATION
GAMETES
STRUCTURE OF GAMETES
SPERM
OVUM
RECOGNITION OF EGG AND SPERM
CAPACITATION
ACROSOME REACTION
SPECIES-SPECIFIC RECOGNITION
GAMETE BINDING AND RECOGNITION
GAMETE FUSION
PREVENTION OF POLYSPERMY
ACTIVATION OF GAMETE METABOLISM
FUSION OF THE GENETIC MATERIAL
SIGNIFICANCE OF FERTILIZATION
CONCLUSIONS
REFERENCES
Gene regulation in eukaryotes in a nutshell covering all the important stages of gene regulation in eukaryotes at transcriptional level, translation level and post-translational level.
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
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.
P elements are transposable elements that were discovered in Drosophila as the causative agents of genetic traits called hybrid dysgenesis. The transposon is responsible for the P trait of the P element and it is found only in wild flies. They are also found in many other eukaryotes.
This PPT consists of 15 slides only explaining Pleiotropy. This is a phenomenon when one gene controls more than one trait , the traits may be related .Generally one gene's product acts for many reactions and so can affect more than one trait. Examples can be seen in pea Coloured flower and pigmentation in leaf axil, frizzle trait in chicken, fur colour and deafness in cats,Human pleiotropic traits are PKU,Sickle cell Anaemia. HOsyndrome , p53 gene etc
INTRODUCTION
DEFINATION
GAMETES
STRUCTURE OF GAMETES
SPERM
OVUM
RECOGNITION OF EGG AND SPERM
CAPACITATION
ACROSOME REACTION
SPECIES-SPECIFIC RECOGNITION
GAMETE BINDING AND RECOGNITION
GAMETE FUSION
PREVENTION OF POLYSPERMY
ACTIVATION OF GAMETE METABOLISM
FUSION OF THE GENETIC MATERIAL
SIGNIFICANCE OF FERTILIZATION
CONCLUSIONS
REFERENCES
Gene regulation in eukaryotes in a nutshell covering all the important stages of gene regulation in eukaryotes at transcriptional level, translation level and post-translational level.
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
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.
P elements are transposable elements that were discovered in Drosophila as the causative agents of genetic traits called hybrid dysgenesis. The transposon is responsible for the P trait of the P element and it is found only in wild flies. They are also found in many other eukaryotes.
This PPT consists of 15 slides only explaining Pleiotropy. This is a phenomenon when one gene controls more than one trait , the traits may be related .Generally one gene's product acts for many reactions and so can affect more than one trait. Examples can be seen in pea Coloured flower and pigmentation in leaf axil, frizzle trait in chicken, fur colour and deafness in cats,Human pleiotropic traits are PKU,Sickle cell Anaemia. HOsyndrome , p53 gene etc
XCI is a dosage-compensation mechanism that evolved to equalize expression levels of x-linked genes in female (2x) and male (1x) by transcriptional silencing of one x-chromosome in female mammalian cells.
XIC
It is responsible for initiating X inactivation in cis: an X-chromosome fragment that carries a Xic can become
inactivated, whereas one in which the Xic is missing cannot.
The Xic is also involved in ‘counting’, whereby only a single X is kept active per two sets of autosomes in a cell, and all other Xic-carrying chromosomes are inactivated.
Homeobox genes /certified fixed orthodontic courses by Indian dental academy Indian dental academy
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Homeobox genes (2) /certified fixed orthodontic courses by Indian dental acad...Indian dental academy
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Dental implants courses.for details pls visit www.indiandentalacademy.com ,or call
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In this PPT I completed that interesting topic , molecular embryology discussing this time molecular regulation of some other systems in the developing embryo, wishing that I could make this as simple as possible.
In this PPT I completed that interesting topic In this PPT I completed that interesting topic , molecular embryology discussing this time molecular regulation of some other systems in the developing embryo, wishing that I could make this as simple as possible.
The term 'segmentation gene' is a classification given to a broad class of genes that are further subdivided into three smaller classes of genes. Within the segmentation gene group, there are gap genes, pair-rule genes and segment polarity genes. They control development in this order.
Why phelogyny has to be this way not other way aroundExaplain bas.pdffazalenterprises
Why phelogyny has to be this way not other way around?
Exaplain based on evidence of
-fossil record
-genetic evdence
-Blast search engine
-nervous system
-body structure or itera itera ori platy helminthes Nematoda Chid a an, ermata Chrdota Chino
Solution
Fossil record & Genetic evidence:
It has clearly observed the predicted order of trait appearance has been increasing as the actual
order of appearance of trait increases among a group of species. Therefore, according to “a
descent with modification of a trait i.e. derived from a common ancestor (a fossil species arose
from a common ancestor)” specifically changing over time. This change was observed in
phylogenetic tree of multicellular organisms (from porifera with no symmetry to bilateral
symmetric species) as “a linear hypothetical relationship between the predicted order of trait
appearance based on trait nesting and the actual order of appearance in the fossil record for a
number of traits among a group of species”.
Fossil species are different and they are transitional fossils as they often resemble and exhibit
both the groups of organisms. They often different in the DNA sequences when perform DNA
sequencing even though they look similar morphologically thereby paleontologists often classify
them as per their interspecific and intraspecific genetic variations (pan genes, core genes)
variations. Fossils are formed due to catastrophism and gradualism, their classification is based
on their body size, and body weight for example dinosaurs is the common ancestors of both birds
and reptiles. Thereby different paleontologists show different family trees for the same fossils.
Blast search engine
The above multicellular eukaryotic classification as per PSI-BLAST considerably along with
matrix -based alignments is used to reveal the amino acid substitution in every species for gene
expression similarity so that protein synthesis can be compared with every species in relation to
higher eukaryotes (chordates). PPSM (position specific scoring matrix) is widely used to get
either positive or negative results in relation to the substitution of the amino acids for protein
multiple sequences.
Delta Blast is more useful in detecting and is identifying “species proteins from lower
multicellular porifera species to annelids, arthropods, non-chordates & chordates” in which
amino acid or nucleotide sequences of the species, which are not closely related compared to the
PSI- BLAST. Some time PSI-Blast also enables to get possible information in identifying the
evolutionary nucleotide substituent’s in the species, which are not closely related.
Nervous system:
The three animal phyla that best represent stages in the evolution of the nervous system of
animals are animals belongs to primitive bilateria, Cnidaria and Ctenophora since these are often
referred as Epitheliozoa. These animals often diversified from primitive sponges where primitive
neuronal system has developed already. The nervous system present.
Observation of Io’s Resurfacing via Plume Deposition Using Ground-based Adapt...Sérgio Sacani
Since volcanic activity was first discovered on Io from Voyager images in 1979, changes
on Io’s surface have been monitored from both spacecraft and ground-based telescopes.
Here, we present the highest spatial resolution images of Io ever obtained from a groundbased telescope. These images, acquired by the SHARK-VIS instrument on the Large
Binocular Telescope, show evidence of a major resurfacing event on Io’s trailing hemisphere. When compared to the most recent spacecraft images, the SHARK-VIS images
show that a plume deposit from a powerful eruption at Pillan Patera has covered part
of the long-lived Pele plume deposit. Although this type of resurfacing event may be common on Io, few have been detected due to the rarity of spacecraft visits and the previously low spatial resolution available from Earth-based telescopes. The SHARK-VIS instrument ushers in a new era of high resolution imaging of Io’s surface using adaptive
optics at visible wavelengths.
Comparing Evolved Extractive Text Summary Scores of Bidirectional Encoder Rep...University of Maribor
Slides from:
11th International Conference on Electrical, Electronics and Computer Engineering (IcETRAN), Niš, 3-6 June 2024
Track: Artificial Intelligence
https://www.etran.rs/2024/en/home-english/
Seminar of U.V. Spectroscopy by SAMIR PANDASAMIR PANDA
Spectroscopy is a branch of science dealing the study of interaction of electromagnetic radiation with matter.
Ultraviolet-visible spectroscopy refers to absorption spectroscopy or reflect spectroscopy in the UV-VIS spectral region.
Ultraviolet-visible spectroscopy is an analytical method that can measure the amount of light received by the analyte.
Earliest Galaxies in the JADES Origins Field: Luminosity Function and Cosmic ...Sérgio Sacani
We characterize the earliest galaxy population in the JADES Origins Field (JOF), the deepest
imaging field observed with JWST. We make use of the ancillary Hubble optical images (5 filters
spanning 0.4−0.9µm) and novel JWST images with 14 filters spanning 0.8−5µm, including 7 mediumband filters, and reaching total exposure times of up to 46 hours per filter. We combine all our data
at > 2.3µm to construct an ultradeep image, reaching as deep as ≈ 31.4 AB mag in the stack and
30.3-31.0 AB mag (5σ, r = 0.1” circular aperture) in individual filters. We measure photometric
redshifts and use robust selection criteria to identify a sample of eight galaxy candidates at redshifts
z = 11.5 − 15. These objects show compact half-light radii of R1/2 ∼ 50 − 200pc, stellar masses of
M⋆ ∼ 107−108M⊙, and star-formation rates of SFR ∼ 0.1−1 M⊙ yr−1
. Our search finds no candidates
at 15 < z < 20, placing upper limits at these redshifts. We develop a forward modeling approach to
infer the properties of the evolving luminosity function without binning in redshift or luminosity that
marginalizes over the photometric redshift uncertainty of our candidate galaxies and incorporates the
impact of non-detections. We find a z = 12 luminosity function in good agreement with prior results,
and that the luminosity function normalization and UV luminosity density decline by a factor of ∼ 2.5
from z = 12 to z = 14. We discuss the possible implications of our results in the context of theoretical
models for evolution of the dark matter halo mass function.
Deep Behavioral Phenotyping in Systems Neuroscience for Functional Atlasing a...Ana Luísa Pinho
Functional Magnetic Resonance Imaging (fMRI) provides means to characterize brain activations in response to behavior. However, cognitive neuroscience has been limited to group-level effects referring to the performance of specific tasks. To obtain the functional profile of elementary cognitive mechanisms, the combination of brain responses to many tasks is required. Yet, to date, both structural atlases and parcellation-based activations do not fully account for cognitive function and still present several limitations. Further, they do not adapt overall to individual characteristics. In this talk, I will give an account of deep-behavioral phenotyping strategies, namely data-driven methods in large task-fMRI datasets, to optimize functional brain-data collection and improve inference of effects-of-interest related to mental processes. Key to this approach is the employment of fast multi-functional paradigms rich on features that can be well parametrized and, consequently, facilitate the creation of psycho-physiological constructs to be modelled with imaging data. Particular emphasis will be given to music stimuli when studying high-order cognitive mechanisms, due to their ecological nature and quality to enable complex behavior compounded by discrete entities. I will also discuss how deep-behavioral phenotyping and individualized models applied to neuroimaging data can better account for the subject-specific organization of domain-general cognitive systems in the human brain. Finally, the accumulation of functional brain signatures brings the possibility to clarify relationships among tasks and create a univocal link between brain systems and mental functions through: (1) the development of ontologies proposing an organization of cognitive processes; and (2) brain-network taxonomies describing functional specialization. To this end, tools to improve commensurability in cognitive science are necessary, such as public repositories, ontology-based platforms and automated meta-analysis tools. I will thus discuss some brain-atlasing resources currently under development, and their applicability in cognitive as well as clinical neuroscience.
What is greenhouse gasses and how many gasses are there to affect the Earth.moosaasad1975
What are greenhouse gasses how they affect the earth and its environment what is the future of the environment and earth how the weather and the climate effects.
This presentation explores a brief idea about the structural and functional attributes of nucleotides, the structure and function of genetic materials along with the impact of UV rays and pH upon them.
A brief information about the SCOP protein database used in bioinformatics.
The Structural Classification of Proteins (SCOP) database is a comprehensive and authoritative resource for the structural and evolutionary relationships of proteins. It provides a detailed and curated classification of protein structures, grouping them into families, superfamilies, and folds based on their structural and sequence similarities.
4. • Genes that control development in Drosophila are very similar to those that control development in
vertebrates
• Early patterning occurs in the syncytial blastoderm and it becomes multicellular at the beginning of
segmentation
• Concentration gradients of proteins (transcription factors) can diffuse, enter nuclei & provide positional
information
• The process of cell fate commitment in Drosophila has two steps: Specification and Determination
Drosophila Development
6. All arthropods are segmented. The body of Drosophila melanogaster is built from 14 segments.
3 segments make up the head with its antennae and mouth parts.
3 segments make up the thorax. Each thoracic segment has a pair of legs. In Drosophila (and other flies), the
middle thoracic segment carries a single pair of wings; the hind segment a pair of halteres.
8 abdominal segments.
SEGMENTS OF A DROSOPHILA
7. SEGMENTATION GENES – Formation of
‘Molecular Blueprint’
Gap
Genes
Pair Rule
Genes
Segment
Polarity
Genes
Segmentation is a stepwise exercise that divides the embryo up into ever smaller units. Its like for cutting a cake into a large
number of equal slices, you would first cut it into large chunks then progressively cut each chunk into smaller slices.
11. PAIR RULE GENES
First Indication of Segmentation
The transcription patterns of these genes are striking in that they divide the embryo into the areas that are
the precursors of the segmental body plan
One vertical band of nuclei (the cells are just beginning to form) expresses a pair-rule gene, then another
band of nuclei does not express it, and then another band of nuclei expresses it again. The result is a “zebra
stripe” pattern
How are some nuclei of the Drosophila embryo told to transcribe a particular gene while their neighbors
are told not to transcribe it? The answer appears to come from the distribution of the protein products of
the gap genes
Three genes are known to be the primary pair-rule genes — hairy, even-skipped, and runt—are essential
for the formation of the periodic pattern, and they are directly controlled by the gap gene proteins. The
enhancers of the primary pair-rule genes are recognized by gap gene proteins, and it is thought that the
different concentrations of gap gene proteins determine whether a pair-rule gene is transcribed or not
13. EXPRESSION OF SEGMENT POLARITY GENES
Once cells form, interactions take place between the cells which are
mediated by the segment polarity genes
Through this cell-to-cell signaling, cell fates are established within
each parasegment.
Encoded proteins are constituents of the Wingless and Hedgehog
signal transduction pathways
One row of cells in each parasegment is permitted to express the
Hedgehog protein, while the other expresses the Wingless protein
Activation of Engrailed gene - cells express Hedgehog protein
In turn, engrailed gene is activated when cells have high levels of
the Even-skipped or Fushi tarazu transcription factors
Engrailed transcription marks the anterior boundary of each
parasegment
The wingless gene is activated – presence of Sloppy-paired protein.
Marks posterior boundary
Right genes being expressed at the right time for pattern formation to occur.
Early in development, the fate of a cell depends on environmental cues, such as those provided by the protein gradients mentioned above. This specification of cell fate is flexible and can still be altered in response to signals from other cells. Eventually, the cells undergo a transition from this loose type of commitment to an irreversible determination. At this point, the fate of a cell becomes cell-intrinsic
The gap genes include hunchback, kruppel and knirps, which define relatively broad regions of the embryo - two to four future segments.
The pair-rule genes are activated in a series of seven separate stripes around the embryo.
The segment-polarity genes are activated in every segment (14 in all) and define the anterior and posterior of each individual parasegment.
Gap genes, whose products mark out coarse subdivisions of the embryo. Mutations in a gap gene eliminate one or more groups of adjacent segments, and mutations in different gap genes cause different but partially overlapping defects. In the mutant Krüppel, for example, the larva lacks eight segments, from T1 to A5 inclusive.
The next segmentation genes to act are a set of eight pair-rule genes. Mutations in these cause a series of deletions affecting alternate segments, leaving the embryo with only half as many segments as usual. While all the pair-rule mutants display this two-segment periodicity, they differ in the precise positioning of the deletions relative to the segmental or parasegmental borders.
Finally, there are at least 10 segment-polarity genes. Mutations in these genes produce larvae with a normal number of segments but with a part of each segment deleted and replaced by a mirror-image duplicate of all or part of the rest of the segment. In gooseberry mutants, for example, the posterior half of each segment (that is, the anterior half of each parasegment) is replaced by an approximate mirror image of the adjacent anterior half-segment
Kruppel is activated by a combination of bicoid and low levels of hunchback but is repressed by high levels of hunchback. This locates Kruppel expression to the centre of the embryo. Knirps is repressed by high levels of hunchback . In this way the initial gradients of morphogens can lead to the establishment of regions within the syncytial blastoderm which themselves lead to the beginning of segmentation
The 2nd stripe of even-skipped (eve) requires bicoid & hunchback. giant represses eve to form a sharp anterior border. Kruppel represses eve to form a sharp posterior border. Since each stripe is independently controlled by combinations of transcription factors (gap genes). Each pair-rule gene has complex control regions with multiple binding sites for each of the different factors. Some factors activate and other inactivate. Some require the activity of the primary pair-rule genes (such as eve and hairy).
Parasegments arise first & each segment is made from the posterior part of one PS and the anterior of the next. Parasegments are delimited by periodic expression pair-rule (PR) genes. Transient grooves on embryo surface (after gastrulation) define the 14 PS. Parasegments act as developmental units
The Engrailed protein activates the transcription of the hedgehog gene in the engrailed-expressing cells. The Hedgehog protein can bind to the Hedgehog receptor (the Patched protein) on neighboring cells. When it binds to the adjacent posterior cells, it stimulates the expression of the wingless gene. The result is a reciprocal loop wherein the Engrailed-synthesizing cells secrete the Hedgehog protein, which maintains the expression of the wingless gene in the neighboring cells, while the Wingless-secreting cells maintain the expression of the engrailed and hedgehog genes in their neighbors in turn. In this way, the transcription pattern of these two types of cells is stabilized. This interaction creates a stable boundary, as well as a signaling center from which Hedgehog and Wingless proteins diffuse across the parasegment.