During the growth of the oocyte not only does the amount of cytoplasm increase in quantity, but it changes in quality by the elaboration and regular distribution of various cell inclusions and specially modified parts of the cytoplasm which, are essential for the development of the embryo. In most animals which have been investigated with modern methods, young oocytes show [...]
The cytoplasm of the egg, and particularly its cortex, starts the chain of reactions which eventually leads to the differentiation of parts of the embryo, it should not be assumed that the structure of the future embryo is rigidly determined by local differences in the cytoplasm of the egg. The local peculiarities of the egg cytoplasm are only some of [...]
In this article we will discuss about the manifestation of maternal genes during the early stages of development. Evidence has been presented that (1) the differences between the various parts of the embryo are not due to differences in their nuclei but to differences in the cytoplasm. From this it may be inferred that (2) the nuclei of the cleavage [...]