Effect of Human Testicular Cells Conditioned Medium on In Vitro Maturation and Morphology of Mouse Oocytes

Testicular cell conditioned medium (TCCM) has been shown to induce female germ cell developmentin vitro from embryonic stem cells (ESCs). Testicular cells (TCs) secrete a variety of growth factors such as growthdifferentiation factor-9 (GDF-9), bone morphogenetic protein 4 (BMP-4), stem cell factor (SCF), leukemia inhibitoryfactor (LIF), and other, that could improve oocyte maturation. Here we have investigated the effect of human TCCM(hTCCM) on in vitro maturation (IVM) and morphology of mouse oocytes.

In this experimental study, 360 germinal vesicle (GV) oocytes were obtained from NMRImice, aged 4-6 weeks that had received 5 IU pregnant mare's serum gonadotropin (PMSG) 48 hours before. GVoocytes were subjected to IVM. 120 GV oocytes were cultured in each medium; hTCCM as the test group, DMEM+ 20%FBS as the control group and Ham’s F10 + HFF medium as the sham group. The rates of the IVM and perivitellinespace (PVS) changes were recorded at 8, 16 and 24 hours after culture. The metaphase II (MII) oocytes weresubjected for in vitro fertilization (IVF) and the fertilization rate was evaluated after 1, 2, and 3 days.

There was a significant difference between the maturation rates in hTCCM (31.67% MII) and the control [0% MII,p <0.05, (7.5% MI, 52.5% deg. and 40%GV)] groups but there was not a significant difference between the maturation ratesin hTCCM and the sham group (53.33% MII, P>0.05). IVF success rate for MII oocytes obtained from IVM in the hTCCMgroup was 28.94% (n=11). Our data showed that hTCCM is an effective medium for GV oocyte growth and maturationcompared to the control medium.

Our findings show that TCCM supports oocyte IVM in mice and affect oocyte morphology.