Frequent horizontal chromosome transfer between asexual fungal insect pathogens

• DOI: 10.1073/pnas.2316284121
• Publication Date: 2024-03-05T18:46:23Z
• Authors: Michael Habig; Anna V. Grasse; Judith Müller; Eva H. Stukenbrock; Hanna Leitner; Sylvia Cremer
• Keywords: Horizontal Gene Transfer; Asexual reproduction; Metarhizium

Entire chromosomes are typically only transmitted vertically from one generation to the next. The horizontal transfer of such has long been considered improbable, yet gained recent support in several pathogenic fungi where it may affect fitness or host specificity. To date, is unknown how these transfers occur, common they are, and whether can occur between different species. In this study, we show multiple independent instances same accessory chromosome two distinct strains asexual entomopathogenic fungus Metarhizium robertsii during experimental co-infection its insect host, Argentine ant. Notably, chromosome—but no other—was transferred donor recipient strain. strain, now harboring chromosome, exhibited a competitive advantage under certain conditions. By phylogenetic analysis, further demonstrate that was horizontally natural environment M. another congeneric pathogen, guizhouense . Hence, not limited observed frequent events within species infections but also occurs naturally across contains genes be involved preferential establishment. These encode putative histones histone-modifying enzymes, as well virulence factors. Our study reveals both intra- interspecies entire more than previously assumed, likely representing uncommon mechanism for gene exchange.