Directional freezing as an alternative method for cryopreserving rhesus macaque (Macaca mulatta) sperm.
The objective was to develop a freezing protocol using a directional freezing (DF) technique for cryopreservation of rhesus macaque sperm and achieve a survival rate comparable to that achieved with a conventional freezing (CF) technique. Rhesus macaque sperm frozen with a DF technique, with cooling rates of 12 or 16 °C/min, had higher post-thaw motility (P < 0.05) than those cooled at 7 °C/min (59.3, 61.1, and 50.3%, respectively). Furthermore, sperm cryopreserved with 5% glycerol and a DF technique had similar frozen-thawed sperm motility to those cryopreserved by a CF technique (63.7 vs. 53.9%, P > 0.05). The function of sperm cryopreserved at the optimized cooling rate using a DF technique was evaluated by in vitro fertilization of oocytes collected from gonadotropin-stimulated rhesus macaques. Of the 38 mature oocytes collected, 78.9% were fertilized and 71.1, 47.4, and 42.1% of the oocytes developed to the 2-cell, morulae, and blastocyst stages, respectively. In conclusion, rhesus macaque sperm was effectively cryopreserved using a DF technique, providing a new and effective method for genetic preservation in this important species.
Si
Wei
W
Kunming Institute of Zoology and Kunming Primate Research Center, Chinese Academy of Sciences, Yunnan Key Laboratory for Animal Reproduction, Kunming, Yunnan 650223, People's Republic of China.
Lu
Yongqing
Y
He
Xiechao
X
Ji
Shaohui
S
Niu
Yuyu
Y
Tan
Tao
T
Ji
Weizhi
W
D000177:Acrosome / Q000648:ultrastructure; D000818:Animals; D015925:Cryopreservation / Q000379:methods / Q000662:veterinary*; D003451:Cryoprotective Agents / Q000494:pharmacology; D005260:Female; D005307:Fertilization in Vitro / Q000662:veterinary; D005615:Freezing; D008253:Macaca mulatta; D008297:Male; D012662:Semen Preservation / Q000379:methods / Q000662:veterinary*; D013081:Sperm Motility / Q000187:drug effects; D013094:Spermatozoa / Q000187:drug effects / Q000502:physiology* / Q000648:ultrastructure
D003451:Cryoprotective Agents