MYCOLab Ai Logo - gold and army green

Changes in intra-host mycovirus population diversity after vertical and horizontal transmission

Summary

Researchers studied how a virus that helps control chestnut blight disease changes when it spreads between fungal cells. They found that when the virus passes through spores, it becomes less diverse, but when it spreads between fungal cells, diversity is maintained better. The fungal host’s genetics strongly influences how many viral variants survive transmission, which has important implications for using this virus as a disease control strategy.

Background

Cryphonectria hypovirus 1 (CHV1) is a mycovirus that infects the chestnut blight fungus and serves as a natural biocontrol agent. Viral populations undergo genetic bottlenecks during transmission, potentially altering their diversity. Understanding these changes is crucial for optimizing the use of CHV1 in disease biocontrol.

Objective

To assess changes in intra-host mycovirus population diversity in CHV1 after vertical transmission via conidia and horizontal transmission via hyphal anastomosis. The study examined two CHV1 subtypes (French 1 and Italian) using PacBio long-read sequencing to measure mutational and variant diversity.

Results

Vertical transmission showed significant bottleneck effects with reduced mutational diversity in both subtypes, though variant numbers decreased for subtype I but increased for subtype F1. Horizontal transmission showed minimal bottleneck effects, and viral diversity transmission was influenced by fungal host genotype at vic2 and vic3 loci. Purifying selection was evident, with higher synonymous than non-synonymous mutations across all replicates.

Conclusion

Strong bottlenecks occur during vertical transmission, shaping mycovirus population diversity through purifying selection. Horizontal transmission efficiency depends on fungal vegetative compatibility, with implications for optimizing CHV1 biocontrol strategies. The findings demonstrate that transmission mode significantly influences viral population evolution in mycoviruses.
  • Published in:Virus Evolution,
  • Study Type:Experimental Study,
  • Source: PMID: 41235154, DOI: 10.1093/ve/veaf082
Scroll to Top