msc part 2, syllabus 2019-2020, oceanography

2. EUKARYOTIC GENE
EXPRESSION
BALE GREESHMA RAMESH
MSC – II 02 ZOOLOGY

3. CONTENTS
• Introduction
• Levels of regulation of gene expression
• Purpose of regulation of gene expression
• Control of gene expression
• Mechanism of regulation of gene expression
• Difference between gene expression in prokaryotes and eukaryotes
• References

4. INTRODUCTION
Gene expression is the combined process of :
• The transcription of a gene into mRNA
• The processing of that mRNA, and
• Its translation into protein (for protein
• encoding genes)

5. LEVELS OF REGULATION OF GENE
EXPRESSION

6. PURPOSE OF REGULATION OF
GENE EXPRESSION
Regulated expression of genes is required for
1. Adaptation
2. Tissue specific differentiation and development

7. CONTROL OF GENE EXPRESSION
• Mammalian cells posses about 1000 times more genetic information than does the bacterium
E. Coli.
• Much of this additional genetic information is probably involved in regulation of gene
expression during the differentiation of tissues and biological processes in the multicellular
organism and in ensuring that the organism can respond to complex environmental challenges.

8. EUKARYOTIC GENE EXPRESSION
(AN OVERVIEW)

9. MECHANISM OF REGULATION OF
GENE EXPRESSION
1. Chromatin remodeling
2. Formation and disruption of nucleosome
structure
• Histone acetylation and
deacetylation
• Modification of DNA
• DNA binding proteins
3. Enhancers and repressors
4. Locus control regions and insulators
5. Gene amplification
6. Gene rearrangement
7. Alternative RNA processing
8. Class switching
9. mRNA stability
10. DNA binding proteins
11. Specific motifs of regulatory proteins
12. RNA editing

11. SUMMARY
• The genetic constitutions of nearly all metazoan somatic cells are identical.
• Tissue or cell specificity is dictated by differences in gene expression of this complement of
genes.
• Alterations in gene expression allow a cell to adapt to environmental changes.
• Gene expression can be controlled at multiple levels by chromatin modifications, changes in
transcription, RNA processing, localization, and stability or utilization.
• Gene amplification and rearrangements also influence gene expression.

12. REFERENCES
www.google for Images

13. THANK YOU!!!