Maturation and fertilization of African lion (Panthera leo) oocytes after vitrification

Abstract The African lion is an excellent model species for the highly endangered Asiatic lion. lions reproduce well in zoos, leading to fact that occasionally ovaries and testis are available in-vitro experiments. We previously performed maturation (IVM) fertilization of oocytes were able produce advanced embryos after intracytoplasmic sperm injection (ICSI) with cryopreserved sperm. Here we examined whether our method also applicable vitrification immature oocytes. Oocytes four lionesses (5–7 years old) obtained euthanasia immediately processed on site. Half (n = 60) subjected IVM a total 32–34 h at 39 °C, 5% CO2 humidified air atmosphere. second group (59 oocytes) was vitrified instantly using Cryotop method. Following 6 days storage liquid nitrogen, warmed as well. Mature both groups fertilized frozen-thawed ICSI. Maturation rate 55% 49.2% control group, respectively. In three cleaved another arrested pronuclei stage. Due low result, sample male used group. Of 7 9 more stopped All did not develop beyond 4 cell This first time in-vitro-derived have been produced following oocyte vitrification.