Effect of Fetal Mouse Lung Tissue Co-Culture on In Vitro Maturation of Mouse Immature Oocytes

Objective: The aim of this study was to evaluate the fetal mouse lung tissue co-culture on in vitro maturation (IVM) of mouse immature oocytes. Materials and Methods: In this experimental study, germinal vesicle (GV) oocytes from ovaries of a group of 25 female mice, 6-8 weeks of age, were dissected after being stimulated by 7.5 IU pregnant mare serum gonadotropin (PMSG) through an intraperitoneal (IP) injection. The fetal lung tissues were then prepared and cultured individually. A total number of 300 oocytes were cultured in the following three groups for 24 hours: control group (n=100) containing only base medium, group I (n=100) containing base medium co-cultured with 11.5- to 12.5-day old fetal mouse lung tissues, and group II (n=100) containing base medium co-cultured with 12.5- to 13.5-day old fetal mouse lung tissues. The proportion of GV and metaphase І (MI) oocytes matured into MІІ oocytes were compared among the three groups using analysis of variance (ANOVA). Correlation test were also used to evaluate the successful rate of IVM oocytes. Results: The proportions of GV oocytes reaching MІІ stage were 46, 65, and 56%, in control, I and II groups, respectively (P<0.05). The percentage of the oocytes remaining at the GV stage were higher in control group as compared with two treatment groups (P<0.05). Conclusion: This study indicated that fetal mouse lung tissue co-culture method increased the percentage of GV oocytes reaching MII stage

Evaluation of specific germ cell genes expression in mouse embryonic stem cell-derived germ cell like cells treated with bone morphogenetic protein 4 in vitro

Background: Bone morphogenetic protein 4 (BMP4) is a significant signaling molecule that involves in initiating of differentiation and performs multifunctional effects on embryonic stem cells (ESCs) and embryos. Objective: The goal of the present study was to evaluate an in vitro differentiation model of mouse embryonic stem cells into germ cells, using BMP4. Materials and Methods: in this experimental study, we used Oct4-GFP mouse ESCs to form embryoid body (EB) aggregations for two days. Then, single cells from EB were cultured for four days with BMP4. Using MTT assay and gene expression levels for evaluation of Mvh and Riken by real-time RT-PCR of six concentrations, 12.5 ng/ ml BMP4 was determined as an optimized dose. Then, the expression level of Fkbp6, Mov10l1, 4930432K21Rik, Tex13, Mvh, Scp3, Stra8, Oct4 were evaluated. Flow cytometry and immunostaning were used to confirm the findings of the real-time RT-PCR. Results: In the +BMP4 group, the genes encoding Riken (p&le;0.001) and Mvh (p&le;0.001) were found to be increased with significant differences compared with the control group. Mov10l1 (p=0.22), Tex13 (p=0.10), Fkbp6 (p=0.90), Scp3 (p=0.61) and Stra8 (p=0.08) were up-regulated without significance differences compared with control group. Flow cytometry analysis showed that the mean number of Mvh-positive cells in the +BMP4 group was greater when compared with ESCs, -BMP4 and EB groups (p=0.03, p&le;0.001, p=0.02, respectively). Conclusion: Down-regulation of Oct4, expression of germ cells genes and meiosis markers expression raise this hypothesis that ESCs were differentiated by BMP4, and may be introduced into the first meiosis as germ cell-like cells