Large single-locus effects for maturation timing are mediated via body condition in Atlantic salmon

Autor: Jaakko Erkinaro, Annukka Ruokolainen, Nikolai Piavchenko, Craig R. Primmer, Noora Parre, Outi Ovaskainen, Tutku Aykanat, Jacqueline E. Moustakas-Verho, Paul V. Debes
Jazyk: angličtina
Rok vydání: 2019
Předmět:
DOI: 10.1101/780437
Popis: Sexual maturation is a pivotal life-history trait that balances the probabilities between mortality and reproduction. Environmental vs. genetic contributions to maturation component traits, such as somatic growth and body condition, remain uncertain because of difficulties in determining causality. In Atlantic salmon, maturation timing associates with a large-effect locus around vgll3, which also links with growth, condition, and maturation in mammals. We investigate environmental vs. genetic contributions to maturation and its component traits by combining controlled breeding with common-garden experimentation in two temperatures. We test whether vgll3 associates with first-year maturation of male salmon and, to avoid reverse causality, whether vgll3 effects express via growth or condition in the males’ non-maturing female relatives. Across 41 families, 4% of males matured in the cold vs. 39% in the warm environment. Maturation rate differed 3.3- to 4.6-fold between vgll3 genotypes, which also explained around 30% of maturation heritability. Female condition differed up to 2% between vgll3 genotypes, which also explained 6-17% of condition heritability. Non-significant vgll3 effects on female length were antagonistic to those for condition but of equal proportional size. When accounting for vgll3 effects, positive genetic correlations between male maturation and female growth increased, whereas those between male maturation and condition decreased, supporting an antagonistic effect of vgll3 on growth and condition. The results indicate that large vgll3 effects on maturation are mediated via large condition effects and suggest vgll3 as a candidate locus for controlling the resource allocation trade-off between somatic growth and body condition. Significance Statement Identifying traits that affect sexual maturation timing and quantifying their relative environmental and genetic importance is a major goal in evolutionary research because of their strong links to fitness. However, cause and effect between maturation timing and such traits often remain unknown. We conducted a common-garden quantitative genetic study using Atlantic salmon to test for genetic contributions of body length and body condition expressed in immature females on maturation of their male relatives. We show that the detection of genetic associations between maturation and length or condition depends on both genetic and environmental factors and suggest that the genetic association with condition chiefly underlies a candidate gene with large effect on maturation that is mediated via variation in body condition.
Databáze: OpenAIRE
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