Alterations in the morphology of nuages in spermatogonia of the fish, Oryzias latipes, treated with puromycin or actinomycin D.

A germ-cell specific organelle, nuage, in Oryzias latipes is polymorphic. Nuages with a strand-like structure and amorphous fibrous bodies can be discriminated from each other; furthermore 2 types of nuages of intermediate morphology are also present. After the administration of puromycin or actinomycin D, nuage morphology in spermatogonia was examined by electron microscopy. Puromycin as well as actinomycin D caused a significant increase in the incidence of nuages with a strand-like structure. These observations indicate that the loss of supply of some materials can induce morphological changes in nuages, suggesting that the polymorphism in nuages of O latipes possibly results from the turnover of nuage materials.