Search

Both oocytes and extracellular vesicles (EV) have emerged as critical regulators of mammalian follicular development; however, the possible interaction between the oocyte‐derived paracrine factor (ODPF) and EV signals has never been examined. Therefore, to explore the possibility of an interaction between oocyte and EV signals, the effects of ODPFs on the biogenesis of EVs as well as the expression levels of transcripts related to EV biogenesis in mural granulosa cells (MGCs) were examined using mice. The results showed that, while oocyte coculture has some effects on the expression levels of transcripts related to EV biogenesis, the number of EV particles present in the conditioned medium were not significantly different between ODPF‐treated and non‐treated MGCs. Therefore, oocytes have no effects on the EV biogenesis by MGCs, at least with respect to the numbers of EV particles.

Oocytes play critical roles in regulating the expression of transcripts encoding the glycolytic enzymes phosphofructokinase, platelet (PFKP) and lactate dehydrogenase A (LDHA) in granulosa cells in mice, but whether this is the case in pigs or other mammals has not been adequately investigated. Therefore, the aim of this study was to determine whether porcine oocytes regulate the expression levels of these transcripts in granulosa cells in vitro. Porcine cumulus cells expressed higher levels of PFKP and LDHA transcripts than mural granulosa cells (MGCs). However, co-culturing with oocytes had no significant effect on the isolated cumulus cells. While murine oocytes promoted the expression of both Pfkp and Ldha transcripts by murine MGCs, porcine oocytes promoted the expression of only Pfkp, but not Ldha transcripts by murine MGCs. Neither murine nor porcine oocytes affected PFKP and LDHA expression by porcine MGCs. Moreover, in the presence of porcine follicular fluid, porcine oocytes maintained the expression of PFKP, but not LDHA by porcine cumulus cells. Therefore, porcine oocytes are capable of regulating the expression of PFKP but not LDHA in granulosa cells in coordination with unknown factor(s) present in the follicular fluid.