Semen Characteristics and Genotyping of Pituitary-Specific Transcription Factor Gene in Buffalo Using PCR-RFLP

Abstract

THIS STUDY aimed to evaluate the sperm characteristics in buffalo bulls and to screen the genetic polymorphisms in PIT-1 gene as bases for selection of bulls with good breeding value. The study was performed on 60 buffalo bulls aged 2-8 years. The animals were divided into three groups according to the age. The first group were between 2 to <3 years (n= 35). The second group were between 3 to <5 years (n=14). The third group were between 5 to <8 years (n=11).Three semen collections were obtained from each animal at 15-day intervals and evaluated for volume, individual motility, live sperm and chromatin integrity %. The semen samples were stored at 20 °C until DNA extraction then polymerase chain reaction (PCR) and DNA amplification were carried out.Restriction fragment length polymorphism (RFLP) was used for genotyping of pituitary-specific transcription factor gene using HinfI-RFLP. The results showed that, ejaculate volume, individual motility and live sperm % were significantly lower in old than adult and young buffalo bulls. While chromatin damage percentage had no significant difference among groups. All buffalo bulls were genotyped as BB with the predominance of B allele where PCR 451 bp fragment was digested into two fragments 244 and 207 bp. It may be concluded that age had adverse effect on semen quality. Monomorphic pattern of the amplicon 451 bp in PIT-1HinfI locus in exon 6 was fixed in Egyptian buffalo with the predominance of B allele and BB genotype in a high frequency (100%).