Abstract
We aimed (I) to simulate an in vivo milieu, through establishing an in vitro paradigm
to study sperm–oviductal
interactions using different segments of oviduct, as well as
different incubation media, and (II) to investigate spatial changes of oviductal gene
expression. Two experiments were designed; one was to investigate the yield of oviduct
aggregates from different oviduct segments; in the second experiment, we observed
effects of different incubation media on sperm–oviductal
binding. Oviduct
cell pellets before (control) and after sperm binding were collected for RNA isolation
and gene expression. Isthmus resulted in a higher aggregate yield and possessed the
highest affinity towards spermatozoa. The different segments of oviduct showed
clear changes in gene expression after sperm binding. TALP medium promoted formation
of a higher number of oviduct aggregates towards spermatozoa. Different
media resulted in profound alterations in isthmus gene expression. Collectively, isthmus
segment in TALP media showed the highest binding affinity to spermatozoa. At
the molecular level, our in vitro model was successful for simulation in vivo milieu.
Thus, our findings could be used as a simple tool to gain more insights into the molecular
regulation of sperm movement, selection and affinity for oviductal binding in
buffaloes.