BIOL 483 Lecture Notes - Lecture 68: Table Tennis, Embryonic Stem Cell, Small Interfering Rna
Document Summary
Pirna mechanism: loci in genome encodes for pirna, pirna cleaved by endonuclease in cytoplasm, pirna/piwi recognises transcripts originating from transcripts and silences them by recruiting h3k4me3 demethylase, h3k9me2/3 methyl transferase, Dnatm3a&l (dna methylases: pirna amplified via ping pong cycle in cytoplasm. This silencing allows for heterocrhomatin establishment/ silencing/ germline protection. Ago = protein that binds single stranded sirna for post trancriptioal gene silencing and heterochromatin formation, needed for pirna generation. Piwi = ago like protein that binds pirna. Rdrp = rna dep rna polymerase that uses sirna as primer to make more dsrna. Post transcriptional gene silencing is related to chromatin. > previously talked about heterochromatin characterised by dname, hp1 to drive tight compaction. Major epigenetic mechanism to explain waddingtons" epigenetic landscape - alternative fates assumed by cells with same genome. > as cells development, totipotent embryonic stem cells start specialising/ differentiating into different cell types.
