Effect of cryopreservation and capacitation on expression patterns of ATP synthesis associated genes in bubaline spermatozoa.

ABSTRACT

This study investigated the expression patterns of certain ATP synthesis associated genes (GAPDHS, PGK2, ENO4 and MDH2) in fresh and frozen-thawed bubaline spermatozoa vis-à-vis capacitation. Eight adult Murrah buffalo bulls, aged 5-7 years, were randomly selected from a bull farm and fresh semen was collected once a week for four weeks (n = 32) from the selected bulls. Simultaneously, frozen straws of the same bulls were collected (n = 32, four straws were pooled per sample). The samples were divided into four groups i.e., fresh non capacitated (control/group 1), fresh capacitated (group 2), frozen non capacitated (group 3) and frozen capacitated (group 4). In all groups mRNA extraction was done. The mRNA expression of GAPDHS was significantly higher in group 3 compared to the other groups, whereas the expression of ENO4 was significantly up-regulated in group 2 and 3 compared to the group 4. Similarly, the mRNA expression of PGK2 was significantly up-regulated in group 3 whereas in case of MDH2, it was significantly higher in group 2, 3 and 4 compared group 1. It can be concluded from our study that freezing and capacitation has a significant effect on the expression dynamics of the ATP synthesis-associated genes warranting necessary interventions in handling procedures to minimise the adverse effect of freezing on ATP synthesis process to ensure persistence of fertilizing ability of sperm.