Parthenogenic Blastocysts Derived from Cumulus-Free In Vitro Matured Human Oocytes

Approximately 20% of oocytes are classified as immature and discarded following intracytoplasmic sperm injection (ICSI) procedures. These oocytes are obtained from gonadotropin-stimulated patients, and are routinely removed from the cumulus cells which normally would mature the oocytes. Given the ready access to these human oocytes, they represent a potential resource for both clinical and basic science application. However culture conditions for the maturation of cumulus-free oocytes have not been optimized. We aimed to improve maturation conditions for cumulus-free oocytes via culture with ovarian paracrine/autocrine factors identified by single cell analysis..Human cumulus-free oocytes from hormone-stimulated cycles are capable of developing to blastocysts when cultured with ovarian factor supplementation. Our improved IVM culture conditions may be used for obtaining mature oocytes for clinical purposes and/or for derivation of embryonic stem cells following parthenogenesis or nuclear transfer

Influence of estrus synchronization of prepubertal gilts on embryo quality

Synchronization and superovulation are commonly used to obtain large numbers of embryos for experimental and practical purposes. This study compared the number, quality, and in vitro development of embryos recovered from gilts following single or double estrus synchronization and superovulation. Prepubertal gilts from the single synchronization group were injected with 1500 I.U. PMSG and 1000 I.U. hCG 72 h later. The double synchronized group of gilts was treated with 750 I.U. PMSG and 500 I.U. hCG 72 h later. After 17 days, 1500 I.U. PMSG followed by 1000 I.U. hCG was administered. Five days after insemination embryos were recovered and cultured for 6 days. Both single and double hormonal stimulation schedules resulted in recovery of elevated numbers of embryos (28.4 and 23.4 vs. 11.3; p<0.01 and p≤0.05, respectively) with a higher percentage of embryos classified as degenerated (39.2% and 43.1%, respectively) compared to the non-stimulated, control group (5.1%). The number of embryos destined for culture did not differ between the single and double synchronized groups. The highest percentage of hatched embryos was observed in the control group. In conclusion, the single synchronization and superovulation schedule is sufficient to obtain high numbers of embryos, however, both synchronization methods resulted in the recovery of considerable numbers of degenerated embryos. A higher number and percentage of hatched embryos after culture was found among embryos from the control group compared to gonadotropin-stimulated gilts.Peer Reviewe

Effects of green tea polyphenols, insulin-like growth factor I and glucose on developmental competence of bovine oocytes

The present study examined the effects of green tea polyphenols (GTP), insulin-like growth factor-I (IGF-I) and glucose on oocyte in vitro maturation, subsequent embryo development and blastocyst quality in bovine. Cumulus-oocyte complexes (COC) were aspirated from the ovaries and cultured in synthetic oviduct fluid supplemented with MEM amino acids (SOFaa) media supplemented with one of the following supplements: GTP (0, 10, 15 and 20 µM), IGF-I (0, 50, 100 and 150 ng/mL) or glucose (0, 1.5, 5.6 and 20 mM) for 24 h. The results showed that oocytes cultured in media supplemented with 15 µM GTP, 100 ng/mL IGF-I and 5.6 mM glucose, in separate experiments, have higher cleavage and blastocyst rates compared with oocytes cultured in media without or with other concentration of GTP, IGF-I and glucose. Then these three substances with the concentration above were added together into SOFaa media and constituted a modified medium (Modified SOFaa). The COC were cultured in control SOFaa media and modified SOFaa media, respectively. The results showed that modified SOFaa media increased the intracellular glutathione concentration of matured oocytes, blastocyst rates and total cell numbers and cell numbers of inner cell mass per blastocyst compared with the control. Supplementing of GTP, IGF-I and glucose synchronously to maturation media can increase the intracellular GSH concentration of oocytes after in vitro maturation, and improve the embryo development and blastocyst quality in bovine