H19 gene methylation study in Indian buffalo (Bubalus bubalis).

The methylation of DNA at cytosine residues within CpG dinucleotides is associated with transcriptional repression and is implicated in maintaining genomic stability and also the silencing of repetitive elements. These imprinted genes are unique as they are expressed exclusively from one parental allele. The present study was carried out to detect methylation status in H19 gene promoter CTCF III region in three Indian buffalo breeds (Jaffarabadi, Surti and Mehsani) by bisulfite sequencing. Methylation percent in Jaffarabadi, Surti and Mehsani buffaloes were found to be 50.19, 70.85 and 52.24, respectively, with mean incidence of methylation percent in H19 in all three breeds as 57.36. Apart from CpG methylation, unexpected nucleotide conversion (T>C, A>G, G>A) and deletion (A and G) after bisulfite sequencing were also observed. We observed no significant relationships in milk yield and milk fat per cent with methylation pattern in H19 gene in any of the three breeds.