DNA methylation in the arcuate nucleus of heifers under two nutritional schedules

DNA methylation was assessed in genomic DNA obtained from the arcuate nucleus of heifers fed to gain body weight at high (HG, n = 4) and low (LG, n = 4) rates from 4.5 to 8.5 mo of age. A methyl-CpG binding domain-based (MBD) protein assay was performed to capture fragments of methylated DNA (methylated-enriched DNA). Input (total) and methylated-enriched DNA were labeled with two different dyes and co-hybridized to a custom-designed oligonucleotide array targeted to genes associated with nutritional inputs and the control of puberty. The ratio of the log2 (enriched/input) of the normalized intensities, were determined. Data was analyzed comparing values of HG versus LG heifers. Two nutritional schedules: HG (n=4 heifers) and LG (n=4 heifers); one array per heifer; methylated enriched DNA (enriched) and total DNA (input) co-hybridyzed into each array Methylated-enriched DNA obtained from a methyl-CpG binding domain-based (MBD) protein assay