Studies on Recipient Rabbit Oocytes in Nuclear Transfer

Studies were carried out to find out the optimal parameters of enucleation and electroactivation ofrecipient rabbit oocyte for successful nuclear transfer,using the fluorescent stain,DAPI(4-6-diamidino-2-phenylindole),and electroactivation.According to the position of metaphasechromosomes in relation to the first polar body,the oocytes were classified into three types:1.thosewith chromosomes juxtaposed to the polar body;2.those with chromosomes in its adjacency; and3.those with chromosomes further removed.The relative proportions of each type appeared to varywith the time of maturation at which the oocytes were collected,with those of the later typesincreasing as the maturation process went further on.In addition,in-vitro cultivation ofelectroactivated oocytes gave the best results with oocytes that matured in-vito after injection ofovulating hormones(LH or HCG)and oocytes that were cultivated in-vitro for 17-19 hours.As aresult,it is recommended that oocytes be selected from those collected from the oviducts 13-15 hoursafter injection of LH or HCG,and electrofusion and electroactivation be done aftermicromanipulation and in-vito cultivation for 2-4 hours.By so doing,it is expected to achieve thehighest enucleation rate of oocytes and the highest fusion rate,the highest activation rate and thehighest development rate of the restructured embryos.

Studies on Recipient Rabbit Oocytes in Nuclear Transfer

Studies were carried out to find out the optimal parameters of enucleation and electroactivation of recipient rabbit oocyte for successful nuclear transfer,using the fluorescent stain,DAPI(4-6- diamidino-2-phenylindole),and electroactivation.According to the position of metaphase chromosomes in relation to the first polar body,the oocytes were classified into three types:1.those with chromosomes juxtaposed to the polar body;2.those with chromosomes in its adjacency; and 3.those with chromosomes further removed.The relative proportions of each type appeared to vary with the time of maturation at which the oocytes were collected,with those of the later types increasing as the maturation process went further on.In addition,in-vitro cultivation of electroactivated oocytes gave the best results with oocytes that matured in-vito after injection of ovulating hormones(LH or HCG)and oocytes that were cultivated in-vitro for 17-19 hours.As a result,it is recommended that oocytes be selected from those collected from the oviducts 13-15 hours after injection of LH or HCG,and electrofusion and electroactivation be done after micromanipulation and in-vito cultivation for 2-4 hours.By so doing,it is expected to achieve the highest enucleation rate of oocytes and the highest fusion rate,the highest activation rate and the highest development rate of the restructured embryos.