Gene expression and maturation evaluation of sheep oocytes cultured in medium supplemented with natural antioxidant source

Abstract

Any improvements in assisted reproduction techniques at experimental level are important in in vitro production of large animal and human embryos. The in vitro embryo production system includes three major steps, namely in vitro maturation of the primary oocytes, in vitro fertilization of the matured oocytes, and in vitro culture of presumptive embryos. The success of in vitro fertilization and embryo culture depends on the success of in vitro maturation. Fenugreek seed extract (FSE) is an important source of steroid hormones, antioxidants, and anti-inflammatories. This study aims to investigate the effect of FSE on the maturation progression, glutathione (GSH) concentration, and expression of certain genes controlling maturation such as growth differentiation factor-9 (GDF-9), transforming growth factor beta receptor 1 (TGFβR1), activin A receptor type II-like 1 (ACVRL1), hyaluronan synthase 2 (HAS2), C-Myc, B-cell leukaemia/lymphoma gene-2 (BCL-2), and BCL2-associated X protein (Bax) of matured sheep oocytes. To carry out this study, cumulus-oocyte complexes (COCs) aspirated from sheep ovaries were cultured in TCM-199 medium supplemented with various concentrations of FSE (0, 1 and 10 μg/mL). The results indicated that the mean values of matured oocytes were 65.2 compared with 47.8 in the control group. Concerning the candidate genes, expression was improved in oocytes matured with FSE when compared with oocytes cultured without extract. In conclusion, the addition of FSE to the maturation medium at 1 or 10 μg/mL concentrations improved the maturation of oocytes.

Keywords: Fenugreek seed extract, in vitro maturation, maturation genes, oocytes, sheep