Cytochemistry of Oogenesis and Early Embryonic Development

Cytochemical investigations on oocyte development, fertilizationand early embryonic development have been reviewed. Inter andintra-group variability in the succession of metabolic phaseswas considered with respect to selection pressures which inturn appeared to modulate phases. Quantitative investigationswere particularly considered. In early development, attention was focused on changes in thechromosomal organization which might reflect on control of development.Some of the unusual forms of chromosomal organizations in earlydevelopment were discussed. Cytochemical studies have not offered any insights into precociousdifferentiation, but they have added substantially to the understandingof chemical and organizational changes during oogenesis andearly development.