The histochemistry and endocrine control of vitellogenesis in goldfish ovaries

Abstract

Histological and histochemical examinations of goldfish ovaries indicate that two types of yolk inclusions are formed during vitellogenesis: first, yolk vesicles, comprised of mucopolysaccharides, followed by yolk granules composed of protein, phospholipid, and neutral lipids. Neither type of yolk develops in the absence of the pituitary. Estrogens regulate the formation of yolk vesicles, while pregnenolone was found to control the deposition of yolk granules. The significance of these two kinds of yolk is discussed. This is the first demonstration of a separate endocrine control for the formation of each of the two yolk types in goldfish ovaries.