Nuclear Changes Occurring During Cannine Oocyte Maturation In Vitro

개 난자의 체외성숙중 핵변화

Canine follicular oocytes were used to establish a reliable system for maturation and fertilization in vitro. Ovaries were obtained from either slaughter house or hormone-primed bitches of mixed breeds. The oocytes were recovered by mincing the ovaries in M2＋BSA. Good quality of oocyte-cumulus complexes (OCCs) were selected and cultured in TCM 199 containing 15% fetal calf serum(FCS) for 24~56 h in an atmosphere of 5% CO2 at 39$^{\circ}C$. Maturation rate of follicular oocytes was >87% showing metaphase I. Unlike other domestic animals the cumulus expansion did not occur fully in canine OCCs although minimum expansion was found between the cumulus cells and corona radiata cells, the clear nuclear morphology was presented for the first time by rapid staining. The IVM system used in this study may be useful to obtain fully maturated metaphase I oocyte in dog.