Expression Profiling of Meiosis-related Genes in Buffalo Gonads Reveals Sex-specific Differences

Abstract

Background: Meiosis is an important process involved in gamete formation and maintenance of genetic variation in mammals. In bovines, meiosis-specific genes regulate chromosome pairing, synapsis, recombination and segregation during germ cell development. Spermatogenesis in the testis occurs continuously and involves active meiotic progression, whereas oocytes in the ovary remain arrested at particular meiotic stages for long durations. The present study was undertaken to analyze the expression pattern of selected meiosis-specific genes in buffalo testicular and ovarian tissues using quantitative real-time PCR (qPCR). Methods: Buffalo testicular and ovarian tissues (n=3) were collected from slaughterhouse. Total RNA was isolated from the tissues and reverse transcribed into cDNA. Real-time PCR was performed to evaluate the expression of meiosis-related genes, including STRA8, HORMAD1, DMC1, SYCP1, SYCP2, SYCP3, REC8 and MLH1. Relative gene expression was calculated using the comparative Ct method. Result: Significantly higher expression (P less than 0.05) of all analysed meiosis-specific genes was observed in testicular tissue compared with ovarian tissue. Fold-change analysis also showed marked upregulation of STRA8, HORMAD1, DMC1, SYCP1, SYCP2, SYCP3, REC8 and MLH1 in the testis, indicating active meiotic progression during spermatogenesis. In contrast, lower expression levels in ovarian tissue were consistent with the arrested meiotic state of oocytes.