Ultrastructure of cultures from embryonic human gonads

We present the results from experimental studies of the ultrastructural changes taking place in the oogonia and spermatogonia under conditions of in vitro culturing. The investigations were performed on gonads of 8-gestation- week-old human embryos. They were examined in vitro using a Georgiev diffusion chamber. It was established that during explantation the oogonia display a higher level of organisation of their cell structures and develop at the same rate as they do in the body, while the spermatogonia delay their differentiation preserving many of the features of undifferentiated cell types. These changes are specific and can be used as early morphological criteria for distinguishing one cell type from the other.