rna processing in devlopmental biology
TRANSCRIPT
![Page 1: RNA Processing in Devlopmental biology](https://reader031.vdocuments.site/reader031/viewer/2022032223/55c7bb6bbb61eb7f698b4680/html5/thumbnails/1.jpg)
![Page 2: RNA Processing in Devlopmental biology](https://reader031.vdocuments.site/reader031/viewer/2022032223/55c7bb6bbb61eb7f698b4680/html5/thumbnails/2.jpg)
Welcome
![Page 3: RNA Processing in Devlopmental biology](https://reader031.vdocuments.site/reader031/viewer/2022032223/55c7bb6bbb61eb7f698b4680/html5/thumbnails/3.jpg)
Presented by:
Sanya Yaseen4010
Presented to:
Sir Danish Riaz
![Page 4: RNA Processing in Devlopmental biology](https://reader031.vdocuments.site/reader031/viewer/2022032223/55c7bb6bbb61eb7f698b4680/html5/thumbnails/4.jpg)
RNA Processing(in cellular Differenciation)
Topic
![Page 5: RNA Processing in Devlopmental biology](https://reader031.vdocuments.site/reader031/viewer/2022032223/55c7bb6bbb61eb7f698b4680/html5/thumbnails/5.jpg)
IntroductionOverview of Gene ExpressionRNA processing in EukaryotesRNA SelectionRNA splicingFamilies of Proteins Sex determination in Drosophilla
Contents
![Page 6: RNA Processing in Devlopmental biology](https://reader031.vdocuments.site/reader031/viewer/2022032223/55c7bb6bbb61eb7f698b4680/html5/thumbnails/6.jpg)
What is Cellular Differenciation?
“Embryonic differentiation is the process of development during which embryonic cells specialize and diverse tissue structures arise.”
![Page 7: RNA Processing in Devlopmental biology](https://reader031.vdocuments.site/reader031/viewer/2022032223/55c7bb6bbb61eb7f698b4680/html5/thumbnails/7.jpg)
What is RNA Processing?
“ The process of gene expression to form a specific protein at a specific place by the process of Translation”.
![Page 8: RNA Processing in Devlopmental biology](https://reader031.vdocuments.site/reader031/viewer/2022032223/55c7bb6bbb61eb7f698b4680/html5/thumbnails/8.jpg)
AN OVERVIEW OF GENE EXPRESSION
The Different Cell Types of a Multicellular Organism Contain the Same DNA.
Different Cell Types Produce Different Sets of Proteins.
A Cell Can Change the Expression of Its Genes in Response to External Signals.
Gene Expression Can Be Regulated at Many of the Steps in the Pathway from DNA to RNA to Protein.
![Page 9: RNA Processing in Devlopmental biology](https://reader031.vdocuments.site/reader031/viewer/2022032223/55c7bb6bbb61eb7f698b4680/html5/thumbnails/9.jpg)
AN OVERVIEW OF GENE EXPRESSION
The Different Cell Types of a Multicellular Organism Contain the Same DNA.
Different Cell Types Produce Different Sets of Proteins.
A Cell Can Change the Expression of Its Genes in Response to External Signals.
Gene Expression Can Be Regulated at Many of the Steps in the Pathway from DNA to RNA to Protein.
![Page 10: RNA Processing in Devlopmental biology](https://reader031.vdocuments.site/reader031/viewer/2022032223/55c7bb6bbb61eb7f698b4680/html5/thumbnails/10.jpg)
cells have ability to change genes expression without altering the nucleotide sequence of their DNA.
If DNA were altered irreversibly during development, differentiated cell would be incapable of guiding the development of the whole organism.
To test this idea, a nucleus from a skin cell of an adult frog was injected into a frog egg whose own nucleus had been removed.
the egg developed normally into a tadpole, showing the normal expression of genes.
![Page 11: RNA Processing in Devlopmental biology](https://reader031.vdocuments.site/reader031/viewer/2022032223/55c7bb6bbb61eb7f698b4680/html5/thumbnails/11.jpg)
![Page 12: RNA Processing in Devlopmental biology](https://reader031.vdocuments.site/reader031/viewer/2022032223/55c7bb6bbb61eb7f698b4680/html5/thumbnails/12.jpg)
![Page 13: RNA Processing in Devlopmental biology](https://reader031.vdocuments.site/reader031/viewer/2022032223/55c7bb6bbb61eb7f698b4680/html5/thumbnails/13.jpg)
AN OVERVIEW OF GENE EXPRESSION
The Different Cell Types of a Multicellular Organism Contain the Same DNA.
Different Cell Types Produce Different Sets of Proteins.
A Cell Can Change the Expression of Its Genes in Response to External Signals.
Gene Expression Can Be Regulated at Many of the Steps in the Pathway from DNA to RNA to Protein.
![Page 14: RNA Processing in Devlopmental biology](https://reader031.vdocuments.site/reader031/viewer/2022032223/55c7bb6bbb61eb7f698b4680/html5/thumbnails/14.jpg)
o many proteins are common to all the cells e.g. structural proteins of chromosomes, RNA polymerases,
DNA repair enzymes, ribosomal proteins, enzymes involved in glycolysis, cytoskelton proteins.
![Page 15: RNA Processing in Devlopmental biology](https://reader031.vdocuments.site/reader031/viewer/2022032223/55c7bb6bbb61eb7f698b4680/html5/thumbnails/15.jpg)
Diferent cell types produce specialized proteins:
e.g. Heamoglobin only produced by reticulocytes a typical differentiated human cell
expresses perhaps 5000–15,000 genes.
large variations seen in the size, shape, behavior, and function of differentiated cells.
![Page 16: RNA Processing in Devlopmental biology](https://reader031.vdocuments.site/reader031/viewer/2022032223/55c7bb6bbb61eb7f698b4680/html5/thumbnails/16.jpg)
AN OVERVIEW OF GENE EXPRESSION
The Different Cell Types of a Multicellular Organism Contain the Same DNA.
Different Cell Types Produce Different Sets of Proteins.
A Cell Can Change the Expression of Its Genes in Response to External Signals.
Gene Expression Can Be Regulated at Many of the Steps in the Pathway from DNA to RNA to Protein.
![Page 17: RNA Processing in Devlopmental biology](https://reader031.vdocuments.site/reader031/viewer/2022032223/55c7bb6bbb61eb7f698b4680/html5/thumbnails/17.jpg)
Cabability to change the Gene Expression due to External Cues.
e.g. Effect of Glucocortocoid Hormone on Liver cells.While some other cells of body do not
effected by that hormone e.g. fat cells illustrate a general feature of cell
specialization
![Page 18: RNA Processing in Devlopmental biology](https://reader031.vdocuments.site/reader031/viewer/2022032223/55c7bb6bbb61eb7f698b4680/html5/thumbnails/18.jpg)
AN OVERVIEW OF GENE EXPRESSION
The Different Cell Types of a Multicellular Organism Contain the Same DNA.
Different Cell Types Produce Different Sets of Proteins.
A Cell Can Change the Expression of Its Genes in Response to External Signals.
Gene Expression Can Be Regulated at Many of the Steps in the Pathway from DNA to RNA to Protein.
![Page 19: RNA Processing in Devlopmental biology](https://reader031.vdocuments.site/reader031/viewer/2022032223/55c7bb6bbb61eb7f698b4680/html5/thumbnails/19.jpg)
To become an active protein, the RNA must be:(1)processed into a messenger RNA by
the removal of introns,(2) translocated from the nucleus to the
cytoplasm,(3) translated by the protein-synthesizing
apparatus(4)must be posttranslationally modified to
become active.• Regulation can occur at any of these
steps during development
![Page 20: RNA Processing in Devlopmental biology](https://reader031.vdocuments.site/reader031/viewer/2022032223/55c7bb6bbb61eb7f698b4680/html5/thumbnails/20.jpg)
![Page 21: RNA Processing in Devlopmental biology](https://reader031.vdocuments.site/reader031/viewer/2022032223/55c7bb6bbb61eb7f698b4680/html5/thumbnails/21.jpg)
Processing in Eukaryotes
O Two Major Ways include:- censoring (RNA Selection) RNA Splicing Censoring:- Nuclear transcripts into mRNARNA Splicing:- splicing of the mRNA into different proteins by using different combinations of potential exons.
![Page 22: RNA Processing in Devlopmental biology](https://reader031.vdocuments.site/reader031/viewer/2022032223/55c7bb6bbb61eb7f698b4680/html5/thumbnails/22.jpg)
![Page 23: RNA Processing in Devlopmental biology](https://reader031.vdocuments.site/reader031/viewer/2022032223/55c7bb6bbb61eb7f698b4680/html5/thumbnails/23.jpg)
RNA Selection
۞ mRNA transcript from pre-mRNA (nuclear RNA (nRNA)
۞ Pre-mRNA is transcribed from DNA ۞ Pre-mRNA contains introns which are
spliced during its movement from nucleus to cytoplsm.
۞ Un-necessary segments are deleted ۞ More genes are transcribed in the
nucleus than are allowed to become mRNAs in the cytoplasm.
![Page 24: RNA Processing in Devlopmental biology](https://reader031.vdocuments.site/reader031/viewer/2022032223/55c7bb6bbb61eb7f698b4680/html5/thumbnails/24.jpg)
Analysis on the transcripts from the CyIIIa genes of the sea urchin
๏ Encode calcium-binding and actin proteins, expressed only in a particular part of the ectoderm of the sea urchin larva.
๏ Trancribed not in ectoderm but also meso & endoderm but only effective in ectoderm of Sea Urchin Larva.
๏ Unprocessed genes are degraded in meso & endoderm.
![Page 25: RNA Processing in Devlopmental biology](https://reader031.vdocuments.site/reader031/viewer/2022032223/55c7bb6bbb61eb7f698b4680/html5/thumbnails/25.jpg)
RNA Splicing
nRNA contains short exons (averaging about 140 bases) & large introns.
By splicing together, different axons form different proteins.
What is an intron in one cell's nucleus may be an exon in another cell's nucleus.
Splicing of RNA is followed by these steps:
1. 5’ capping 2. polyadenyl tail3. removal of introns 4. editing
![Page 26: RNA Processing in Devlopmental biology](https://reader031.vdocuments.site/reader031/viewer/2022032223/55c7bb6bbb61eb7f698b4680/html5/thumbnails/26.jpg)
5’ Capping
![Page 27: RNA Processing in Devlopmental biology](https://reader031.vdocuments.site/reader031/viewer/2022032223/55c7bb6bbb61eb7f698b4680/html5/thumbnails/27.jpg)
Polyadenyl Tail
![Page 28: RNA Processing in Devlopmental biology](https://reader031.vdocuments.site/reader031/viewer/2022032223/55c7bb6bbb61eb7f698b4680/html5/thumbnails/28.jpg)
Removal of Introns
![Page 29: RNA Processing in Devlopmental biology](https://reader031.vdocuments.site/reader031/viewer/2022032223/55c7bb6bbb61eb7f698b4680/html5/thumbnails/29.jpg)
Editing of mRNA
![Page 30: RNA Processing in Devlopmental biology](https://reader031.vdocuments.site/reader031/viewer/2022032223/55c7bb6bbb61eb7f698b4680/html5/thumbnails/30.jpg)
Process of Translation
![Page 31: RNA Processing in Devlopmental biology](https://reader031.vdocuments.site/reader031/viewer/2022032223/55c7bb6bbb61eb7f698b4680/html5/thumbnails/31.jpg)
Families of Proteins
• Deletion of different exons in different cells forms different families of proteins.
• Instead of one gene-one polypeptide, one can have one gene-one family of proteins.
• for example:- α-tropomyosin gene to encode brain, liver, skeletal muscle, smooth muscle, and fibroblast forms of this protein.• These are called Splicing
isoforms.
![Page 32: RNA Processing in Devlopmental biology](https://reader031.vdocuments.site/reader031/viewer/2022032223/55c7bb6bbb61eb7f698b4680/html5/thumbnails/32.jpg)
![Page 33: RNA Processing in Devlopmental biology](https://reader031.vdocuments.site/reader031/viewer/2022032223/55c7bb6bbb61eb7f698b4680/html5/thumbnails/33.jpg)
Sex determination in Drosophilla
![Page 34: RNA Processing in Devlopmental biology](https://reader031.vdocuments.site/reader031/viewer/2022032223/55c7bb6bbb61eb7f698b4680/html5/thumbnails/34.jpg)
![Page 35: RNA Processing in Devlopmental biology](https://reader031.vdocuments.site/reader031/viewer/2022032223/55c7bb6bbb61eb7f698b4680/html5/thumbnails/35.jpg)
![Page 36: RNA Processing in Devlopmental biology](https://reader031.vdocuments.site/reader031/viewer/2022032223/55c7bb6bbb61eb7f698b4680/html5/thumbnails/36.jpg)