Dna-Synthesis Studied in Later Growth Cycles and in Zoosporangium Development of Allomyces macrogynus

Abstract

Synchrony of duplication cycles in Allomyces macrogynus was maintained through five cycles to the end of vegetative growth. In a culture in which hyphal emergence was inhibited the fourth cycle was abnormal. No DNA synthesis occurred before septation when zoosporangia developed in culture medium. When organisms were induced to make sporangia by transfer to water there was a small apparent increase in DNA prior to but not after septation. The unavoidable extraction of wall glycopeptide poses some problems in nucleic acid assays. Partial inhibition by 10µM benomyl allowed continued growth with large rhizoids at every apex. Partial inhibition by mitomycin allowed continued growth without any further morphological differentiation.