Isolation And Culture Of Bactrian Camel Follicles After Cryopreservation

Objective:Studies were conducted to examine the effects of the cryoprotectants on the camel follicles on the histological and ultrastructural level and make a preliminary study on the culture of pre-antral follicles (PFs) in camel, which gave grounds for the production of Bactrian camel in vitro.Methods:Tissues were analyzed by histology and transmission electron microscopy after vitreous cryopreservation. After recovery, follicles were isolated and cultured, using trypan blue to identify survivability.Results:Four groups were compared for the cryopreservation of follicles, including A1(DMSO+PROH+EG), A2(DMSO+PROH), A3(DMSO+EG), A4(PROH+EG). The results revealed that A1was the best for the cryopreservation of follicles (31.39%percentage of the pre-antral follicles were normal), which had significant difference with the others(A2:22.03%, A3:21.39%, A4:11.5%). In total,73.3%percentage (min.50%, max.100%) of the pre-antral follicles in the fresh ovaries (n=6) appeared histologically normal. In contrast, ovaries plunged in liquid nitrogen within cryoprotectants (n=6) showed a mean histological pre-antral follicles viability of only31.39%(min.0.0%, max.50.0%), equally. The two groups were compared using two-tailed homoscedastic t test, all yielding a highly significant result (p<0.001). To a certain extent, the ultrastructure was abnormal, showing that mitochondria were swollen and mitochondria cristae were unclear or disappeared. The high dead rate was presented in vitro culture. The survival rate (SR) was just18.95%(min.0%, max.37.5%) on the6th day. The SR didn’t increase significantly even though the insulin was added. However, the number of naked oocytes was reduced. The antral formation was observed in the study on the18th day.Conclusions:The cryoprotectants used in the study destroyed the integrity of camel follicles and reduced their viability. The feasibility of in vitro culture of camel follicles was approved, in spite of imperfections in culture system. The more studies in future are needed to fill in the blank of camel cryopreservation and culture in vitro.