Genomic analysis of <i>Ancylistes closterii</i>, an enigmatic alga parasitic fungus in the arthropod-associated Entomophthoromycotina

However, there are still many poorly studied obligate parasitic or symbiotic fungi for which we lack any genomic information or knowledge of where they fit in the fungal phylogeny. <i>Ancylistes</i>, an endoparasite of desmid green algae, is such an understudied fungal genus that is classified among Entomophthoromycotina in Zoopagomycota on the basis of morphology.

However, this relationship is perplexing, because Zoopagomycota is almost entirely composed of animal-associated fungi. In this study, we found and cultivated <i>Ancylistes closterii</i> with its green algal host <i>Closterium</i> sp. and sequenced its genome to investigate its phylogenetic position and evolution. Phylogenetic analyses using rDNA and genome-scale data sets showed that <i>A. closterii</i> was sister to other Entomophthoromycotina fungi, confirming the taxonomic position of <i>Ancylistes</i>.