Unraveling the genomic and phylogenetic complexity of the under-studied microfungus Basidiobolus: Insights from 19 newly sequenced genomes.

Abstract

Basidiobolus is a globally distributed genus of non-Dikarya fungi within Zoopagomycota, known for its presence in diverse ecological niches ranging from soil and decaying organic matter to vertebrate gastrointestinal tracts. Despite its ecological and medical relevance, the taxonomy and evolutionary relationships within the genus remain poorly resolved due to limited genomic resources. In this study, we present 19 newly sequenced Basidiobolus genomes, expanding the available genomic data. Using short-read Illumina sequencing, assembly, and annotation pipelines, we characterize gene content, assess completeness, and explore biosynthetic gene content across isolates, one with 14 genomes that includes B. ranarum and another with eight genomes that includes B. meristosporus; a single genome of B. heterosporus forms a distinct lineage. Several isolate groups exhibit deep divergence suggestive of novel species, underscoring the need for expanded sampling and taxonomic revision. Functional annotations reveal a rich repertoire of biosynthetic gene clusters, including non-ribosomal peptide synthetases, polyketide synthases, and hybrid clusters, pointing to an underexplored reservoir of secondary metabolite diversity. These findings position Basidiobolus as a compelling model for investigating fungal evolution, ecological adaptation, and natural product biosynthesis.