Lecture 11: The Eukaryotic Chromosome

I. Importance

II. Components of the Chromosome

DNA, Histone and Non-Histone Proteins

H2A, H2B, H3, H4 = Core Histone proteins, found in nucleosome

Non-Histone proteins found in scaffolding and important for chromosome movement

III. Chromosome Karyotype and Evolution

Comparison of banding patterns

Related species pack their genes differently

IV. Telomeres

Specialized terminal structure on eukaryotic chromosomes that ensure the maintenance and accurate replication of the two ends of each linear chromosome

Composed of DNA and proteins

Problem: RNA primer prevents complete DNA replication

Solution: Telomerase

V. Centromere

Role: holds sister chromatids together, ensures proper movement of chromosomes

VI. Chromosome Packing and Gene Activity

DNase sensitivity test

VII. Heterochromatin

Position effects

Barr Bodies: X Chromosome inactivation

VIII. Conclusion

Terms and Concepts to Know: Centromere, telomere, nucleosome, karyotype, Barr bodies,

Position effect and position effect variegation, Heterochromatin, euchromatin, histone and non-histone

proteins

Figures 12.2, 12.3, 12.5, 12.6, 12.9-12.14