Synchronized development of gametophytic germlings of the aquatic phycomycete Allomyces macrogynus.

Abstract

Gametophytic germlings ofAllomyces macrogynus are examined with regard to the sequence of developmental events which have been suggested to be effected by long-lived messenger RNA. During encystment of the meiospore, the cytoplasmic triplet microtubules are depolymerized, the gamma bodies are mobilized, the nuclear cap envelope is fragmented and the cap ribosomes are dispersed, the side body complex breaks into its components, and a cyst wall is deposited. All these processes take place prior to the appearance of significant amounts of protein synthesis. The first fission of the mitochondria occurs shortly after the onset of protein synthesis but before detectable RNA synthesis. The developmental sequence of gametophytic and sporophytic germlings was found to be very similar.