HLTB22H3 Lecture Notes - Lecture 9: Methyl Group, Cytosine, Chromatin
Document Summary
Epigenetic landscape of development: concept representing embryonic development, illustrates various developmental pathways a cell may take in differentiation. Ball rolls down the diagram and it chooses which out of many ways it goes. Recall: activation of gene transcription: gene transcription is rst step of gene transcription when a segment of dna is copied, rst step is when activator binds to dna segment and activated transcription. Dna methylation: gene activation: when a gene is expressed at a particular time, gene inactivation: ability to manipulate gene expression levels has been essential to the study of gene function and biological processes. Cpg methylation: sections of dna where cytosine is followed by a guanine with a phosphate in between, represses gene transcription. Affects function of gene; methyl groups project into the major groove of dna and inhibit transcription. Dnmts: enzymes that catalyze the transfer of a methyl group to dna from s- adenosylmethionine.
