Summary
A bioRxiv preprint reports that tunicamycin, a compound produced by Streptomyces bacteria, induced unisexual reproduction in Cryptococcus fungi. The reported cycle included meiotic recombination and spore formation.
A bioRxiv preprint reports that tunicamycin, a natural product made by Streptomyces bacteria, can induce unisexual reproduction in Cryptococcus, a genus of human-pathogenic yeasts. The researchers report that the induced process progressed beyond filament growth to include meiotic recombination and the formation of basidiospores.
Unisexual reproduction allows a fungus to reproduce without a compatible mating partner. The findings suggest that a chemical produced by bacteria can activate this developmental route in Cryptococcus under the conditions studied.
A chemical cue activates the reproductive cycle
The researchers tested both bacterial confrontation and purified tunicamycin. In the preprint’s abstract, both are reported to trigger hyphal differentiation, a filament-forming stage of fungal development, alongside meiotic recombination and basidiospore formation. Whole-genome sequencing and analyses of single-nucleotide polymorphisms (SNPs) were used to confirm recombination.
The involvement of meiosis—the cell-division process that reshuffles genetic material—distinguishes the reported cycle from filament formation alone. The authors also report that tunicamycin-induced development requires canonical sexual regulators and the machinery used in meiosis.
Transcriptomic profiling, which measures patterns of gene activity, indicated a staged response. Genes associated with stress and the cell cycle were induced early; genes linked to filamentation were enriched later. The capacity to respond varied among natural isolates of C. neoformans, while the authors report that it was conserved in Cryptococcus gattii.
The results identify tunicamycin as a possible chemical signal between bacteria and fungi. The authors propose that such interkingdom signalling could influence fungal evolution in natural environments. That ecological significance remains a proposed implication: the reported findings concern induced fungal development, rather than measurements of how often this interaction occurs in nature.
The study is a bioRxiv preprint, posted on 5 October 2026.