2. Heterochromatin Formation — It’s all about silencing!

This lecture develops the relationship between chromatin packaging and control of gene expression, a significant epigenetic system that allows the genome to respond to changes in environment, both the external environment and physiological cues (e.g., hormone responses). There are 7 slides developing the importance of epigenetic regulation, particularly the silencing of repeats by heterochromatin packaging; 6 slides on histone post-translational modification; 9 slides on the discovery of Heterochromatin Protein 1a and its validation using Position Effect Variegation (in Drosophila), including the model for spreading of heterochromatin; 8 slides on HOW heterochromatin packaging can lead to silencing; 3 slides on the inheritance and manipulation of the heterochromatic state; and 4 slides on mapping chromatin states across the fly genome.