A CLONED TOY POODLE PRODUCED FROM SOMATIC CELLS DERIVED FROM AN AGING (14-YEAR OLD) FEMALE DOG

Abstract

To date, dogs have been cloned successfully through somatic cell nuclear transfer (SCNT) using donor cells derived from large breed dogs at age of 2 months to 3 years of age. The aim of the present study was to produce a small breed dog (toy poodle) with a large breed oocyte-donor and surrogate females by SCNT. In vivo oocytes collected by flushing the oviducts of large breed oocyte donors were reconstructed with a donor somatic cell. Somatic cells derived from an aging female poodle, 14 years old, were cultured and used for SCNT. The donor cell and oocyte were fused by electric stimuli, activated chemically and transferred into the oviducts of large breed recipient females. A total of 123 cloned embryos were surgically transferred into the oviduct of seven recipient dogs. One became pregnant, maintained to term, and delivered a cloned offspring weighing 190 g by Caesarean section. Whereas the cloned poodle was genetically and phenotypically identical to the donor dog, mitochondrial DNA in the cloned poodle originated from the oocyte donor of the large breed dog. The mean telomere length of the cloned dog was not significantly different from that of the donor dog. In conclusion, the present study produced for the first time a small size breed (toy poodle) by nuclear transfer of donor cells of an aging dog into oocytes collected from a large breed and embryo transfer of the reconstructed embryo into the large breed recipient female. (platform)