Assessment of oocytes retrieved from stimulated and unstimulated ovaries of pig‐tailed macaques (Macaca nemestrina) as a model to enhance the genetic diversity of captive lion‐tailed macaques (Macaca silenus)

摘要

AbstractSteroid hormone levels were measured during unstimulated menstrual cycles of pig‐tailed macaques (Macaca nemestrina) and lion‐tailed macaques (Macaca silenus). The values were similar, suggesting that the pig‐tailed macaque may be an appropriate model for in vitro fertilization and embryo transfer in the lion‐tailed macaque.Two follicular stimulation protocols were compared to evaluate the yield and quality of the oocytes obtained from pig‐tailed macaques. Five animals received a regimen of PMSG (Protocol I) and five received a regimen of Pergonal (Protocol II). Oocytes from natural cycles were obtained from seven pig‐tailed macaques during 21 cycles. If the oocytes extruded a polar body, they were inseminated and then observed for penetration and cleavage. Oocytes that produced quality embryos were transferred to recipient pig‐tailed macaques or rhesus macaques (Macaca mulatta).Oocytes from natural cycles had a higher percentage of good embryos produced from inseminated eggs (22.7) compared to Protocol I (10.3) or Protocol II (14.2). However, Protocol I and Protocol II yielded more quality embryos/cycle (2.0, 1.4, respectively) than natural cycles (0.24). Pig‐tailed macaques were refractory to a second PMSG protocol, but Pergonal and natural cycles could be repeated on the same individual before or after PMSG. A total of 12 embryos were transferred to six pig‐tailed macaques and three rhesus macaques during natural or stimulated cycles. No pregnancies resulted. Refinement of IVF‐ET techniques in pig‐tailed macaques should make the procedure a viable choice to enhance the genetic diversity of captive