Synthesis of LDH-1 during mamalian oogenesis and early development.

Nuclear multiplication stage embryos were punctured in either the anterior, midlateral, or posterior regions. Both embryos and adults were examined for defects, and the defects were correlated with whether there had been any leakage of cytoplasmic material from the egg at the time of puncturing. Embryonic defects were found, correlated to the site of damage, in all three regions. A number of embryos was followed through development and it was found that 15.1% of the embryos which leaked cytoplasm hatched into larvae, compared to 82.3% of those which did not leak any cytoplasm. Morphological defects arising as a result of lateral puncture only were observed in adults. Many sterile adults were obtained from eggs in which the posterior region had been punctured. The results show that nuclear multiplication embryos are well able to tolerate the disturbance of the cortical cytoplasm created by puncture, but only rarely are they able to compensate for the actual loss of material by regulation. The results were similar to those observed after puncturing Drosophila embryos at the cellular blastoderm stage.