In vitro development of marbled cat embryos derived from interspecies somatic cell nuclear transfer.

The objective of the study was to investigate interspecies Somatic Cell Nuclear Transfer (iSCNT) techniques in marbled cats (Pardofelis marmorata), using domestic cat and rabbit oocytes as the recipient cytoplasm. The recipient oocytes were obtained from ovariohysterectomized cats and superovulated rabbits. The donor cells were collected from a male marbled cat that had died in captivity. Experiment 1 was conducted to observe the development of cloned marbled cat embryos (marbled cat donor cells-domestic cat oocytes; MC-DC), derived from oocytes matured for 24, 36 and 42 h. The result showed that the developmental rates of MC-DC cloned embryos at the 4-8 cell and the morula stages derived from oocytes cultured for 24 h were significantly greater than those cultured for 36 and 42 h (p < 0.05). Experiment 2 was conducted to compare the fusion rate of MC-DC couplets, fused by inducing different fusion voltages, 2.1 or 2.4 kV/cm. The result showed that there was no difference in fusion efficiency between the 2.1 and 2.4 kV/cm fusion protocols. Experiment 3 was conducted to compare the developmental rate of MC-DC and domestic cat (DC-DC) cloned embryos. In vitro fertilized cat embryos served as a control. The development of MC-DC and DC-DC cloned embryos to the 4- to 8-cell, morula and blastocyst stages was not significantly different. However, the development rates at morula and blastocyst stages of control were significantly greater than those of cloned embryos (p < 0.05). Experiment 4 rabbit (RB) oocytes were used as a recipient cytoplasm for marbled cat and domestic cat cloned embryos (MC- RB and DC-RB). RB-RB cloned embryos served as a control. There were no differences in the developmental rates between MC-RB, DC-RB and RB-RB embryos. In conclusion, marbled cat fibroblast cells can be reprogrammed in domestic cat and rabbit oocytes, and by using iSCNT it might be possible to produce marbled cat offspring in the future.