Duplication Cycles in a Non-Septate Fungus, Allomyces macrogynus

Abstract

Spores released from 2-3-day-old cultures at 20°C were induced to germinate by addition of casein hydrolysate, and spores which attached early to glass were selected to obtain synchronous germination. In the first two duplication cycles organisms could only differentiate zoosporangia immediately after mitosis. In later cycles spores were not produced by organisms transferred during mitosis. The alternating growth at the apex and base during the first two cycles was assigned to the G1 (preparation for DNA replication) and G2 (preparation for mitosis) phases of the cycle respectively.