# Identification of Critical Candidate Genes Controlling Monokaryon Fruiting in Flammulina filiformis Using Genetic Population Construction and Bulked Segregant Analysis Sequencing

## TL;DR

This study identifies a key gene involved in fruiting body formation in the edible fungus Flammulina filiformis using genetic analysis techniques.

## Contribution

The study discovers a novel gene and SNP associated with monokaryotic fruiting in F. filiformis.

## Key findings

- A 10 kb genomic region on scaffold19 was identified as critical for monokaryotic fruiting.
- The gene FV-L110034160, involved in pre-mRNA splicing, was pinpointed as a key regulator.
- A T→G SNP caused a serine-to-alanine substitution, affecting fruiting phenotypes.

## Abstract

Fruiting body formation in edible fungi is a critical development process for both scientific understanding and industrial cultivation, yet the underlying genetic mechanisms remain poorly elucidated. This study aimed to identify key genes regulating monokaryotic fruiting in Flammulina filiformis. A genetic segregation population was constructed through selfing purification and hybrid segregation of the FF002 strain, followed by mapping candidate genes with bulked segregant analysis sequencing (BSA-seq). A 10 kb genomic region on scaffold19 was identified, pinpointing the gene FV-L110034160, which encodes a U2 snRNP complex component involved in pre-mRNA splicing. A T→G SNP located 121 bp downstream of the ATG codon caused a serine-to-alanine substitution, disrupting a conserved domain and altering fruiting phenotypes. Phylogenetic analysis further revealed conservation of this gene in fungal genera. These findings elucidate a key regulatory gene controlling monokaryotic fruiting in F. filiformis, providing novel insights into fruiting body formation mechanisms and establishing a foundation for genetic studies in other edible fungi.