CSB329H1 Lecture Notes - Insertional Mutagenesis, Embryonic Stem Cell, Dna Demethylation
Document Summary
Has a copy of the genome that can generate numerous cells or the whole organism. Strategies to maintain genome stability: quiescence at rest, rare division; protects genome from dna damage during, enhanced dna repair, preventing mobile element activity in the genome piwi genes in stem and germ replication. cells. During differentiation and self renewal of escs, dna may damage during replication. Homologous recombination factors expressed more in escs to restore dna, re-enter cell cycle. Higher fidelity because it uses intact copy from the other homologous chromosome to direct repair. Other repair mechanisms more prone to error, introduce insertions or deletions. Apply: can modify embryonic stem cells in models by providing a repair template. Retrotransposons and insertional mutagenesis: translate retrotransposons, rna goes through reverse transcriptase creating dna, synthesis of a second dna strand, the retrotransposon dna inserts into the genome. Disrupts coding region causing frameshift affects gene expression, completely different translation due to triplet nature of codons.
