Genomic Insights into Convergent Evolution of Rock-Inhabiting Fungi

A new report published in Molecular Biology and Evolution has revealed the genomic underpinnings of convergent evolution in rock-inhabiting fungi, highlighting their unique adaptations to rocky environments. The study, conducted by a team of researchers from Nankai University, analyzed the genomes of nine rock-inhabiting fungi and eighteen non-rock-inhabiting fungi, uncovering key genetic differences that contribute to the remarkable survival capabilities of these organisms. The research sheds light on the specialized evolution of the Mnn9 family in driving the convergent success of phylogenetically diverse rock-inhabiting fungi.

Key Takeaways:

• Rock-inhabiting fungi display striking convergence in morphology and physiology, characterized by meristematic growth, melanized cell walls, and extreme stress tolerance.
• Comparative genomic analysis revealed that rock-inhabiting fungi possess compact, gene-dense genomes with contraction of genes involved in nutrient uptake and secondary metabolism, alongside expansions in cell wall biosynthesis, lipid metabolism, and stress-responsive pathways.
• Two genes under positive selection across multiple rock-inhabiting lineages were identified: Ino80 ATPase (chromatin remodeling) and the ER chaperone BiP (protein folding).
• A Mnn9-like clade has expanded exclusively in rock-inhabiting fungi, with two RIF-specific amino acid substitutions predicted to enhance protein stability.
• RNAi-mediated knockdown of an Mnn9-like gene in Rachicladosporium sp. confirmed its role in cell wall mannosylation, osmotic stress response, and the transition from meristematic to filamentous growth.
• The research highlights the specialized evolution of the Mnn9 family in driving the convergent success of phylogenetically diverse rock-inhabiting fungi in rocky environments.
• The study used a comparative genomic approach, analyzing the genomes of nine rock-inhabiting fungi and eighteen non-rock-inhabiting fungi.
• The research included the following authors from Nankai University: Luwen Yan, Rong Fu, Shunxian Wang, Dongsheng Wei, Qi Wu, Xingzhong Liu, and Meichun Xiang.
• The publisher of the journal Molecular Biology and Evolution is Oxford University Press.

Statistics:

• The study analyzed the genomes of 9 rock-inhabiting fungi and 18 non-rock-inhabiting fungi.
• The research identified 2 genes under positive selection across multiple rock-inhabiting lineages: Ino80 ATPase and the ER chaperone BiP.
• A Mnn9-like clade has expanded exclusively in rock-inhabiting fungi.
• RNAi-mediated knockdown of an Mnn9-like gene in Rachicladosporium sp. was used to confirm its role in cell wall mannosylation, osmotic stress response, and the transition from meristematic to filamentous growth.

Sources:

• NewsRx. New Molecular Biology and Evolution Data Have Been Reported by Researchers at Nankai University (Genomic Insights into Convergent Evolution: Adaptation to Rocky Habitats in Rock-inhabiting Fungi). Life Science Weekly. October 21, 2025; p 3359.
• Luwen Yan et al. Genomic Insights into Convergent Evolution: Adaptation to Rocky Habitats in Rock-inhabiting Fungi. Molecular Biology and Evolution, 2025.