Developmental Potential of Hybrid Arabian Tahr X Goat Embryos Produced In Vitro and Implanted into Domestic Goat Recipients.

Abstract

The Arabian Tahr is one of the endangered species found entirely in the mountains of United Arab Emirates and Oman. Assisted reproductive technologies (ARTs) such as in vitro fertilization and embryo transfer could play essential role in saving the population of endangered species. Identifying suitable surrogate mothers will be one means of increasing the population of the Arabian Tahr through assisted reproduction. The objective of the present study was to investigate the ability of Tahr sperm to fertilize goat oocytes in vitro, and the developmental potential of the resulted hybrid embryos. Oocytes were obtained from ovaries of slaughtered domestic goats and in vitro matured in TCM (with fetal calf serum, FSH, LH, Na-pyruvate, estradiol and cysteamine) in a humidified atmosphere of 5% CO2 and 39°C. Matured oocytes were in vitro fertilized with frozen-thawed or fresh Tahr sperms collected by electro-ejaculation at a concentration of 1-2 x 106 sperm/ml. Fertilized oocytes were cultured in SOF medium and cleavage was checked 44 h post insemination. Over 70% and 55% cleavage rates were obtained with fresh and frozen sperms, respectively. When the hybrid embryos (2 to 4-cell stages) were surgically transferred into 4 domestic goats, pregnancy was established in 3 goats as indicated by progestin level in fecal samples and by ultrasound examination at 2 months of pregnancy. Our results confirmed that Arabian Tahr's sperms are capable of fertilizing the domestic goat's oocytes in vitro, and that pregnancy could be achieved when the resulted hybrid embryos are transferred into domestic goats. This finding is crucial for us in our effort to produce a hybrid offspring that can be used as surrogate mothers to propagate the Arabian Tahr. (poster)