L & S C30Y Lecture 9: Lecture 9
Document Summary
Epigenetics it takes more than 4 letters to spell you. Put info on a chromosome, h3 or h4 sub-unit. How does it all fit: it is wound up in incredible ways at multiple levels of organization basic packaging of our genome. Nucleosomes with dna around them then assemble into. 30 nanometer solenoid (we still don"t know what that is) Solenoids are then wrapped and that is wrapped again and again until it becomes a chromosome: dna self-assembles around histones, all our genomes are wrapped up in nucleosomes. Euchromatin: the part of the genome when genes are easily expressed. Heterochronatin: the part of the genome where genes get silences. The big idea: the collection of chemical modifications makes a kind of epigenetic code. Modifications are read by proteins with specialized domains that bind modifications. Proteins that recognize and bind to particular modifications. Erases most epigenetic tags so that the fertilized egg can develop into any type of cell.