Genetic architecture of threshold reaction norms for male alternative reproductive tactics in Atlantic salmon (Salmo salar L.)

• Published in: Scientific reports Vol. 7; no. 1; p. 43552
• Main Authors: Lepais, Olivier, Manicki, Aurélie, Glise, Stéphane, Buoro, Mathieu, Bardonnet, Agnès
• Format: Journal Article
• Language: English
• Published: London Nature Publishing Group UK 10.03.2017; Nature Publishing Group
• Subjects: 45/23; 45/29; 45/77; 631/158/2464; 631/158/856; 631/158/857; 631/181/2474; 631/208/182; Animals; Biodiversity and Ecology; Chromosome Mapping; Environmental Sciences; Experimental design; Female; Fish; Genetic diversity; Genetic factors; Genetic Linkage; Humanities and Social Sciences; Male; Mating; Maturation; Migration; multidisciplinary; Natural populations; Phenotypic variations; Quantitative Trait Loci; Quantitative Trait, Heritable; Reproduction - genetics; Rivers; Salmo salar; Salmo salar - genetics; Salmo salar - growth & development; Salmon; Science; Sexual Behavior, Animal; natural population; tacon; salmon; facteur environnemental; genêtic factor; salmo salar; facteur génétique; tactique de reproduction alternative; atlantic; modèle; maturation précoce; numerical models; population naturelle; reproduction
• ISSN: 2045-2322; 2045-2322
• DOI: 10.1038/srep43552

Alternative mating tactics have important ecological and evolutionary implications and are determined by complex interactions between environmental and genetic factors. Here, we study the genetic effect and architecture of the variability in reproductive tactics among Atlantic salmon males which can either mature sexually early in life in freshwater or more commonly only after completing a migration at sea. We applied the latent environmental threshold model (LETM), which provides a conceptual framework linking individual status to a threshold controlling the decision to develop alternative traits, in an innovative experimental design using a semi-natural river which allowed for ecologically relevant phenotypic expression. Early male parr maturation rates varied greatly across families (10 to 93%) which translated into 90% [64–100%] of the phenotypic variation explained by genetic variation. Three significant QTLs were found for the maturation status, however only one collocated with a highly significant QTL explaining 20.6% of the variability of the maturation threshold located on chromosome 25 and encompassing a locus previously shown to be linked to sea age at maturity in anadromous Atlantic salmon. These results provide new empirical illustration of the relevance of the LETM for a better understanding of alternative mating tactics evolution in natural populations.