Mareike Richter, Doreen Schachtschabel
Mucor mucedo, Blakeslea trispora, Phycomyces blakesleeanus are heterothallic Mucoraceae, one family of zygomycetes. During intra-specific interaction two mating types of one species recognize each other for sexual differentiation. In sexual morphogenesis of Mucor mucedo hyphae first differentiate to zygophores. After touch and exchange of chemical signals of different mating types, dark, round zygospores develop. On the other hand inter-specific interaction, called parasitism, takes place between two different species of zygomycetes.


Fig.1: Morphological stadiums of sexual differentiation in Mucor mucedo (Jones, B. E., Willianson, I. P. & Gooday, G. W. (1981). Sex pheromones in Mucor. In Sexual Interactions in Eukaryotic Microbes, pp. 179-198. Edited by D. H. O'Day and P. A. Horgen. New York, London: Academic Press.)
The molecular control of differentiation in zygomycetes is done by the trisporic acid pathway, which is not known in detail. A complementary change of metabolites is postulated. Only the complementary mating type is able to convert the diffusing metabolite.

Fig.2: Trisporic acid pathway of Blakeslea trispora (Werkman, B. A. (1976). Localization and partial characterization of a sex-specific enzyme in homothallic and heterothallic Mucorales. Archives of Microbiology 109, 209-213. modified)
Trisporoids probably control intra- and inter-specific communication. The clarification of chemical and molecular biological mechanisms is an important objective to explain differentiation processes of these fungi in detail and maybe detect new differentiation factors. The experimental work will be done in cooperation with Prof. Johannes Wöstemeyer and Dr. Christine Schimek of the Institute of General Microbiology and Microbial Genetics of the Friedrich Schiller Universität, Jena. One main point is to understand the chemical basis of trisporoid action by focusing on the functional groups, chiral centers and E/Z-isomers. Therefore configurationally pure isomers of different trisporoids will be synthesized. Those will be used as references for chromatographic analysis and testing substrates for biological activities.