| Abstract: | The fate of proteins formed during meiotic maturation was examined after fertilization. Rabbit ovarian oocytes were labelled in vitro with 3H]lysine and fertilized after transfer to recipients. A significant accumulatin of the label was detected autoradiographically only in fully grown male and female pronuclei. Pig oocytes at the germinal vesicle and metaphase I stages were labelled with 3H]lysine, 3H]methionine or 3H]tryptophan and fertilized. Pronuclei were labelled by all 3 precursors. During cleavage, eggs labelled with 3H]lysine lost the nuclear label by the 4-cell stage. However the 3H]methionine label was present in the cytoplasm and marked in the nuclei at the 4-cell stage, while the 3H]tryptophan label was still clear in 8-cell embryos. |
