1. Molecular Biology Eukaryotic Genome Structure

2. The human genome: nuclear and mitochondrial components

3. Genetic Material in the Living Cells

4. Composition of Chromosome DNA Histones (Major proteins) Non-histone (Small amounts) p q

5. Karyotype

6. chromosomes

7. DNA Condensation: Why?

8. Histones

9. Nucleosomes: The Basic Units of DNA Condensation

10. Chromatin “beads-on-a-string” structure (10 nm Fiber)

11. Histone H1 Binds the Nucleosome to Form the Chromatosome

12. Two models of the 30 nm chromatin fiber

14. Higher-Order Chromosome Structure Involves Loops and Coils Looped chromatin fibre folds Chromatin fibre loops along the protein scaffold

15. Low power high power Scaffold protein DNA loops

16. The major structures in DNA compaction

17. The major structures in DNA compaction (contd.)

18. Regulation of chromatin structure Post-translational modifications of histones Exchange of canonical histones with their alternative sequence variants. Chromatin remodeling via ATP-dependent complexes DNA methylation

19. Chromosomes Metaphase chromosomes in Eukaryota: –the highest level of chromatin structure (the most condensed) –observed only during cell division After cell division: –metaphase chromosomes disappear –chromatin condensation is reduced –genomic DNA exists in the form of heterochromatin and euchromatin

20. Different forms of chromatin show differential gene activity euchromatin heterochromatin