PRODUCTION OF NUCLEAR TRANSFER BUFFALO EMBRYOS USING OOCYTES FROM OVARIES STORED AT LOW TEMPERATURES

Abstract

Philipp J Vet Anim Sci 2011, 37 (1): 1-10

The present study was conducted to determine the possibility of producing buffalo clone embryos after nuclear transfer using oocytes from ovaries stored at low temperatures. Buffalo ovaries were collected using physiological saline solution at temperatures of 10, 15 or 32ºC during transport from slaughterhouse to the laboratory. Aspiration of oocytes from ovaries stored at 10 and 15°C was done at 20-24 hr post collection (hpc). Cumulus-oocyte complexes retrieved were matured in vitro for 22-23 hr and were subjected to nuclear transfer. Likewise, oocytes from ovaries collected at 32°C were aspirated immediately upon arrival (4-6 hpc), matured in vitro, and subjected to nuclear transfer to serve as control. The reconstructed embryos were cultured in vitro and assessed for embryonic development. The results indicate that the rates of maturation, enucleation, fusion, cleavage, and blastocyst formation did not differ significantly (P<0.05) between low temperatures groups (10 and 15°C) and these results were comparable to that of the control group wherein the ovaries were stored at 32°C during transport. In sum, the results suggest that buffalo ovaries can be held at temperature ranging from 10 to 15°C for up to 24 hr without compromising developmental competence of the retrieved oocytes. The present work demonstrated for the first time that the oocytes retrieved from buffalo ovaries stored at low temperatures were viable and pre-implantation embryos were successfully produced after nuclear transfer.