MBB331_Week10-Fall-2011

Sex eg paternal unmethylated igf ii paternal

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Unformatted text preview: ve sites sites • Methylation of CpG islands in promoters Methylation generally prevents transcription initiation and this repression mediated by binding of proteins MeCP-1 & MeCP-2 MeCP-1 52 METHYLATION STATE PERPETUATION METHYLATION • Maintenance of gene Maintenance methylation state constitutely expressed genes unmethylated, but genes under tissue-specific control vary in level of methylation vary • Mammalian methylases: Mammalian maintenance methylase constitutively converts hemimethylated sites to fully hemimethylated methylated sites - essential methylated • Methylation lost either by Methylation lost demethylase or failure of methylation of hemimethylated site after DNA replication DNA Lewin Genes VII 2000 Oxford University Press 53 • • • GENOMIC IMPRINTING GENOMIC IMPRINTING IMPRINTING: distinguishes paternal and maternal alleles in the mouse embryo Sex determined imprinting: eg. Sex eg paternal (unmethylated) IGF-II paternal expressed, whereas maternal expressed whereas maternal (methylated) not… reset every not reset generation during gametogenesis: maternal alleles in sperm demethylated, paternal alleles in egg methylated (ensures correct methylation in next generation) next evid...
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This note was uploaded on 03/26/2014 for the course MBB 321 taught by Professor Davidson during the Spring '11 term at Simon Fraser.

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