PHYLOGENETIC POSITION OF THE FUNGI OF THE FAMILY CHOANEPHORACEAE CONSIDERED IN TERMS OF HETEROTHALLISM

The influence of Mucorales sex hormones (trisporic acids, TA) on the c apacity of Blakeslea trispora strains to synthesize isoprenoid compoun ds from acetyl-CoA as a precursor was investigated. In the presence of TA, the (-) strains synthesized significantly more beta-carotene, phy tofluene, sterols, and ubiquinone Q(9) than the (+) strains. With the (-) strains of B. trispora, TA changed the composition of the cell wal ls (CW), increasing their protein content. Based on these findings and a number of other taxonomic criteria (the ratio between oleic and lin oleic fatty acids in the lipid bilayer and the chemical composition of the CW), it is suggested that fungi of the genera Blakeslea and Cunni nghamella are phylogenetically related and these two genera should be classified into one family Choanephoraceae.