Induction of abnormal male gametes and androgenesis in the aquatic PhycomyceteAllomyces

Summary

Induction of cleavage of the cytoplasm in the gametangium of a predominantly male strain of the aquatic PhycomyceteAllomyces under conditions of oxygen starvation, in the presence of dilute lactic acid, or dilute phosphate buffer, pH 7.0, resulted in multinucleate-multi-flagellate gametes. Under certain conditions the frequency for such abnormal gametes approached 70%. Phosphate buffer pH 7.0, at a concentration of 5 × 10⁻³-1×10⁻² M and an incubation time of 90 minutes was found to be most effective in inducing multi-flagellate-multinucleate gametes. Nuclear fusion and multiple nuclear fusions were observed in these abnormal gametes as they developed into sporophytic thalli on dilute nutrient agar (YpSS/10). Multinuclear gamete development and nuclear fusion was analysed by electron microscopy. The reported observations reveal the occurrence of androgenesis from multinuclear male gametes inAllomyces.