Dissecting the loci underlying maturation timing in Atlantic salmon using haplotype and multi-SNP based association...

Area of Science:

• Evolutionary Biology
• Population Genetics
• Quantitative Genetics

Background:

• Characterizing mutational effect sizes in fitness-related traits is crucial for understanding evolutionary processes.
• Genetic architectures of fitness traits in wild populations are often poorly understood, hindering evolutionary insights.
• Sea age at maturation in Atlantic salmon is a key fitness-related trait with potential genetic underpinnings.

Purpose of the Study:

• To investigate the mutational composition of candidate regions associated with sea age at maturation in wild Atlantic salmon.
• To characterize the genetic architecture of maturation timing in a wild population using advanced genomic methods.
• To identify specific loci and single nucleotide polymorphisms (SNPs) influencing maturation timing.

Main Methods:

• Employed haplotype-based and multi-SNP Bayesian association methods on sequencing data from 313 wild Atlantic salmon individuals.
• Tested 116 previously identified candidate regions for association with maturation timing.
• Analyzed the contribution of individual SNPs to the variation explained by associated loci.

Main Results:

• Detected significant associations at five out of 116 candidate loci for maturation timing in wild populations.
• Found that four of the five associated loci were primarily driven by single SNPs, indicating simple allelic architectures.
• Identified one locus with a potentially more complex allelic architecture, suggesting diverse genetic underpinnings for the trait.

Conclusions:

• The genetic architecture of sea age at maturation in wild Atlantic salmon exhibits diversity, including both simple and complex allelic patterns.
• This study provides a robust multi-SNP framework for future research on genetic variation underlying phenotypes in wild populations using sequencing data.
• Findings contribute to a deeper understanding of the genetic basis of fitness-related traits and their evolution in natural systems.