PCR-SSCP Analysis of Genetic Variation in DNMT Gene Family in Holstein Cattle

Members the DNA Methyltransferases (DNMT) gene family have been shown to play fundamental roles in regulating embryonic growth and development from embryonic fertilization to postnatal life; through regulating the establishment and/or maintenance of specific epigenetic marks. The present study was conducted to identify potential reported mutations within the exon 33 of DNMT-1, intron 4 of DNMT-3a and intron 3 DNMT-3a genes and their relationship with birth weight in Holstein cows. A total of 60 blood samples from Holstein dairy cattle with records of weight from birth to adult age were randomly collected from industrial dairy cattle farm located in Kerman province. Genomic DNA samples was extracted using Phenol-Chloroform method and target sequence was amplified with PCR using specific primers. Polymerase chain reaction-single stranded conformational polymorphism (PCR-SSCP) and silver nitrate staining methods was used for screening potential mutation in target sequences. According to the results of this study, in all cases, no mutation in target sequence were identified as all samples had the same specific SSCP pattern with respect to their size. The lack of polymorphism in these region may be attributable to an relative inefficiency of PCR-SSCP for mutation detection, small sample size, stochastic effects of genetic drift and/or conserved nature of these genes due to either natural or artificial selection. According to the results of this study, analyzed sequence may not be informative as molecular marker for birth weight in Holstein cattle.