Abstract
The mechanism of preferential destruction of chloroplast nucleoids from the male parent in young zygotes in Chiamydomonas reinhardii was studied using inhibitors of transcription, ultraviolet irradiation and an epifluorescent microscopy. Addition of an inhibitor (rifampisin) of transcription in chloroplasts has no effect on the preferential destruction of chloroplast nucleoids while addition of inhibitors (actinomycin D, α-amanitin) inhibited remarkably the preferential destruction of chloroplast nucleoids. In addition, UV irradiation of male gametes had no effect on the preferential destruction of chloroplast nucleoids while irradiation of female parent blocked the preferential destruction approx. 100%. The results suggest that soon after mating, the RNA which is synthesized in the female nucleus is involved in the preferential destruction of chloroplast nucleoids of male origin and there is a coupled RNA-protein system for the preferential destruction in young zygotes.
