PRODUCTION OF NORMAL YOUNG FOLLOWING TRANSFER OF MOUSE EMBRYOS OBTAINED BY IN-VITRO FERTILIZATION BETWEEN CRYOPRESERVED GAMETES

Unfertilized oocytes (C57BL/6N and C3H/He) and epididymal spermatozoa (DBA/2N and Jcl:ICR) from mice were frozen separately and stored at -1 96-degrees-C. After thawing, in vitro fertilization was performed usin g C57BL/6N oocytes and DBA/2N spermatozoa, C57BL/6N oocytes and Jcl:IC R spermatozoa, C3H/He oocytes and DBA/2N spermatozoa, and C3H/He oocyt es and Jcl:ICR spermatozoa. Embryos developed to the two-cell stage by incubation in vitro were transferred to the oviducts of female recipi ents on the first day of pseudopregnancy (day when vaginal plug was co nfirmed). The rate of development to two-cell embryos in each group wa s in the 22-45% range. When these two-cell embryos were all transferre d to recipients, offspring were produced from 23-35% of the embryos.