LAUSR

Abstract The present study aimed to detect and quantify the expression of buffalo PLCZ1 mRNA (buPLCZ1 mRNA) in buffalo semen and to determine its oocyte-activation and fertilizing ability through IVF. Buffalo semen samples were collected and subjected to standard subjective physical and microscopic evaluation of semen characteristics. Small amount of fresh semen sample was taken for molecular experiment. The rest of the samples were processed into frozen semen. Both fresh and frozen semen were subjected to Reverse Transcriptase quantitative PCR (RT-qPCR) technique to determine and quantify buPLCZ1 mRNA expression. Subsequently, 40 bulls with known buPLCZ1 mRNA content were evaluated for its oocyte-activation activity through IVF using frozen semen. Correlation analysis was done to determine the relationship between the expression of buPLCZ1 mRNA and percentage of IVF, and other semen variables. PLCZ1 mRNA expression in buffalo semen was observed variable among donor bulls, but was not significantly different (P > 0.05) between fresh and frozen semen. The result suggests that the cryopreservation procedure does not affect the expression of buPLCZ1 mRNA in semen. Statistical analysis showed that the expression of buPLCZ1 mRNA in fresh semen was strongly correlated with that of frozen semen (r = 0.992; P   0.05) nor with Post-Thaw Motility (r = −0.0313; P > 0.05). A strong relationship between buPLCZ1 mRNA concentration and IVF rate indicates that buPLCZ1 mRNA concentration can be used to assess oocyte-activation and fertilizing potential of the buffalo semen. The present study essentially demonstrated buPLCZ1 mRNA as biological marker for male fertility and that molecular technique serves as an objective approach of semen quality evaluation to enhance bull selection for genetic improvement in water buffaloes.