Isolation of strains and their genome sequencing to analyze the mating system of Ophiocordyceps robertsii

PLoS One. 2023 May 2;18(5):e0284978. doi: 10.1371/journal.pone.0284978. eCollection 2023.

Abstract

The fungal genus Ophiocordyceps contains a number of insect pathogens. One of the best known of these is Ophiocordyceps sinensis, which is used in Chinese medicine and its overharvesting threatens sustainability; hence, alternative species are being sought. Ophiocordyceps robertsii, found in Australia and New Zealand, has been proposed to be a close relative to O. sinensis, but little is known about this species despite being also of historical significance. Here, O. robertsii strains were isolated into culture and high coverage draft genome sequences obtained and analyzed. This species has a large genome expansion, as also occurred in O. sinensis. The mating type locus was characterized, indicating a heterothallic arrangement whereby each strain has an idiomorphic region of two (MAT1-2-1, MAT1-2-2) or three (MAT1-1-1, MAT1-1-2, MAT1-1-3) genes flanked by the conserved APN2 and SLA2 genes. These resources provide a new opportunity for understanding the evolution of the expanded genome in the homothallic species O. sinensis, as well as capabilities to explore the pharmaceutical potential in a species endemic to Australia and New Zealand.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Base Sequence
  • Genes, Mating Type, Fungal* / genetics
  • Hypocreales* / genetics
  • Phylogeny
  • Reproduction

Supplementary concepts

  • Ophiocordyceps robertsii

Grants and funding

This work received funding from the University of Melbourne (AI), SproutX (NAA, IW) and Artesian Capital Management (NAA, IW). The funders had no role in study design, data collection and analysis, decision to publish, or preparation of the manuscript.