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All mice experiments and animal care protocols were approved by Koç University Local Ethics Committee for Animal Experiments (approval number: 2013-06). The animals were kept in Koç University, Animal Research Facility of Center for Translational Medicine (KUTTAM) under 12 h light-12 h dark cycle, and a diet of commercial pellet food ad libitum and automatic water containers were provided. 2.1. Embryo collection CB6F1 (C57BL⁄6j ͯ BALB⁄c) female mice (n = 24) were intraperitoneally injected (IP) with 10 IU of equine Abstract: Leptin is a hormone-like protein consisting of 167 amino acids. The aim of this study is to compare the effects of different leptin concentrations on in vitro and in vivo embryo development rates. In vitro development rates were investigated by embryo culture studies, and in vivo implantation rates and the quality of embryos were assessed by embryo transfers to the recipient mice. The results showed that addition of leptin into the embryo culture medium at 10 and 100 ng/mL doses supported the in vitro development of mouse embryo. Moreover, leptin increased the total cell number of blastocyst, particularly the trophectoderm cells. In vivo assessment showed a significant increase in the proportion of the embryos implanted in 10 and 100 ng/mL groups, compared to the control group. In conclusion, leptin supplement in embryo culture medium increases implantation rates in mice.

In the present study we investigate the effects of parthenogenetic activation on in vitro embryo development and quality in different activation periods. oocytes were obtained 14 hours after human chorionic gonadotropin (hCG) injection from superovulated B6D2F1 female mice then parthenogenetic activation started 18 hours after hCG injection. The oocytes were activated at different activation periods for 3, 4, 5 or 6 hours in 10 mM strontium chloride (SrCl2) + 5 μg/mL-1 Cytohalasine B (CB) + 5 nM Trichostatin A (TSA) containing a Ca 2+ free Chatot Ziomek Brinster (CZB) activation medium, followed by further incubation for two hours at 37°C and 5% CO2 in embryo culturing medium + TSA. The results in the present study suggested that the parthenogenetic activation of the 6 hour activation period was found to be higher than at 3, 4 and 5 hours.

Çalışmamızın amacı, partenogenetik aktivasyonda farklı fare ırklarında in vitro embriyo gelişimi ve kalitesi üzerindeki etkilerinin araştırılmasıdır. Bu çalışmada, B6CBAF1, C57BL/6j, and B6D2F1 farelerin superovulasyon ile elde edilen oositleri kullanılmıştır. Superovule edilen fareler, insan koryonik gonadotropin (hCG) uygulamasından 14 saat sonra oositler elde edildi ve 18 saat sonra partenogenetik aktivasyona başlandı. Oositler, 10 mM SrCl2 + 5 μg/mL-1 sitokalazin B (CB) + 5 nM trikostatin A (TSA) Ca 2+ içermeyen Chatot Ziomek Brinster (CZB) medyumu içerisinde 6 saat bekletildi. Aktivasyon sonrası, embriyo kültür medyumu + TSA’da inkübatörde 37°C ve %5 CO2 ortamında 2 saat bekletildi. Son olarak, tüm embriyolar 120 saat süre ile kültüre edildi. Bu çalışmadan elde edilen sonuçlar göre, B6D2F1 ırkının partenogenetik aktivasyon başarısı, C57BL/6j ve B6CBAF1 ırklarına göre daha yüksek bulundu.

Leptin is a hormone-like protein of 167 amino acids. As an adipocyte-related hormone it has an important role in weight regulation and physical fitness but also has effects on reproductive and other physiological mechanisms. The aim of the present study was to investigate the effects of different concentrations of leptin added to the culture media, the quality, in vitro development rate, and in vivo rate of mouse embryos. Superovulated CB6F1 (C57BL/6XBalb/c) hybrid female mice (5–6 weeks of age) were killed ~18 to 20 h after hCG administration. Single-cell embryos were flushed from the oviducts of the dead mice with human tubal fluid medium supplemented with HEPES and 3 mg mL–1 of BSA. They were cultured in Quinn's cleavage medium supplemented with 4 mg mL–1 of BSA in 5% CO2, 37°C until reaching 2-cell stage. The 2-cell embryos were randomly divided into 4 groups and cultured in Quinn's blastocyst medium supplemented with 4 mg mL–1 BSA + 0, 10, 50, and 100 ng mL–1 leptin (L0, L10, L50, and L100) in 5% CO2, 37°C until the blastocyst stage. Some of the developing blastocysts were used for differential staining for the inner cell mass and trophectoderm (TE) cells [Mallol et al. 2013 Syst. Biol. Reprod. Med. 59,117–122]. Some of them were transferred into pseudopregnant females (CD1) on the 2.5 to 3.5th days and kept until the 13.5th day of pregnancy for the in vivo development rate. The results were evaluated using one-way ANOVA with Bonferroni post-hoc test in SPSS 22.0. The P-values <0.05 were considered statistically significant. Each experiment was repeated at least 4 times. The blastocyst development rates of L0, L10, L50, and L100 were 92.57% (162/175), 97.16% (205/211), 97.80% (178/182), and 97.85% (182/186), respectively. The in vitro development rates were significantly higher in the L10, L50, and L100 compared with L0 (P < 0.05). The inner cell mass cells of L0, L10, L50, and L100 were 13.17, 14, 16, and 15.43. There was no significant difference between the groups in terms of inner cell mass cells (P > 0.05). The TE cells of L0, L10, L50, and L100 were 47, 56.4, 53.7, and 58.57, respectively. The TE numbers were significantly increased in the presence of L10 and L100 compared with L0 (P < 0.05). The in vivo development rates of L0, L10, L50, and L100 were 13.51% (5/37), 48.72% (19/39), 15.38% (6/39), and 41.03% (16/39), respectively. The in vivo development rates of L10 and L100 were significantly higher than for L0 and L50 (P < 0.05). The resorption rates of L0, L10, L50, and L100 were 10.8% (4/37), 30.8% (12/39), 12.8% (5/39), and 20.5% (8/39), respectively. There was no significant difference between the groups in terms of the resorption rates (P > 0.05). This study found that L10, L50, and L100 were supporting the development of the embryos in the in vitro culture. The L10, L50, and L100 significantly increased the total cell numbers. The L10 and L100 were particularly effective on the number of the TE cells. In conclusion, 10 and 100 ng mL–1 leptin have a positive effect on the in vitro, quality and in vivo development of the mouse embryo. Therefore, leptin seems to play an important role on the embryo development and in vivo development. Research supported by TUBITAK-113O223.