The effect of alcohol on the methylation status of the imprinting control regions contained within three developmentally significant loci
Year: 2010
Type: dissertation
Abstract: Imprinted loci are critical in foetal development and most are regulated by the \nmethylation-specific CTCF binding protein which binds imprinting control regions \n(ICRs). The ICR is located between two genes that comprise imprinted loci, which are \nreciprocally expressed in a parent-of-origin specific manner. Maternally \nhypomethylated ICRs allow CTCF binding, creating a boundary element which \nprevents downstream enhancers from acting on the paternally expressed gene \nupstream of the ICR. Conversely, the hypermethylated (imprinted) paternal ICR \nprevents CTCF binding, allowing downstream enhancers to act on the gene upstream \nof the ICR, while suppressing the downstream maternally expressed gene. Alcohol \nand its metabolites are able to reach the testes via the blood supply and are known \nto reduce global DNA methylation by disrupting the folate, methyl group and \nhomocysteine pathway. This may therefore affect gene expression at imprinted loci, \nwhose parental alleles are discriminated by the imprinting status at the ICR. \nThe effect of pre-conception paternal alcohol exposure on the DNA methylation of \nthree paternally imprinted ICRs (H19, Rasgrf1, IG-DMR) as well as the maternally \nimprinted Snrpn ICR was examined in mouse sperm and their offspring. Male mice \nwere gavaged with ethanol or sucrose. DNA was extracted from sperm of treated \nmales and tail biopsies from offspring. Samples were bisulphite modified and the ICRs \nPCR amplified. DNA methylation patterns of ICRs were analysed by sequencing and \nquantitatively via pyrosequencing. Sperm samples of ethanol treated males did not \nshow significant demethylation when compared to sucrose treated mice, with the \nexception of H19 CpG 7, Rasgrf1 CpG 26 and Snrpn CpG 10 (p=0.024, 0.014 and
Author: Jaysen Knezovich
Language: English
Subfield: Genetics
Domain: Life Sciences
Open Access status: green
OpenAlex ID: W2275777713