マウス2細胞期卵から分離した割球の体外発育

抄録

The present paper describes the in vitro development of single blastomeres isolated from 2-cell eggs in mice.
Two-cell eggs were recovered from CF 1f1 females which were injected with 5 IU of PMS followed 48 hours later by 5 IU of HCG and were mated with fertile CF#1 males. Zona pellucidae were removed by incubation in Hanks medium containing 0.2 pronase for 5 to 8 minutes, and the zona free eggs were washed two times with Hanks medium. Blastomeres were separated mechanically with a glass pipet in Ca⁺⁺and Mg⁺⁺free Hanks medium containing 0.02% EDTA. Separated blastomeres were incubated in drops of culture medium (Whitingham 1971) coverd with paraffin oil at 37°C in an atmosphere of 5% CO₂., 95% air for 72 hours.
Of the 576 single blastomeres isolated from 288 2-cell eggs, 416 (72.2%) developed to blastocyst in culture for 72 hours. This rate was similar to the rate of development into blastocyst in zona free 2-cell eggs, although lower than that of normal 2-cell eggs. The proportion of monozygotic pair embryos developed to blastocyst was 61.5%, in this culture.