Genetic basis of sexual dimorphism in the threespine stickleback Gasterosteus aculeatus

Abstract

Sexual dimorphism (SD) in morphological, behavioural and physiological features is common, but the genetics of SD in the wild has seldom been studied in detail. We investigated the genetic basis of SD in morphological traits of threespine stickleback (Gasterosteus aculeatus) by conducting a large breeding experiment with fish from an ancestral marine population that acts as a source of morphological variation. We also examined the patterns of SD in a set of 38 wild populations from different habitats to investigate the relationship between the genetic architecture of SD of the marine ancestral population in relation to variation within and among natural populations.The results show that genetic architecture in terms of heritabilities, additive genetic variances and covariances (as well as correlations) is very similar in the two sexes in spite of the fact that many of the traits express significant SD. Furthermore, population differences in threespine stickleback body shape and armour SD appear to have evolved despite constraints imposed by genetic architecture. This implies that constraints for the evolution of SD imposed by strong genetic correlations are not as severe and absolute as commonly thought.

Repeated Lake-Stream Divergence in Stickleback Life History within a Central European Lake Basin

“…Additional stream-resident populations were from the Beaver, Boot, Joe’s, McCreight, Pye, and Robert’s systems [43], and from the inlet stream to Misty Lake [39], [75], on Vancouver Island. These freshwater samples were complemented by collections of marine stickleback from two estuaries on the east coast of Vancouver Island (Cluxewe: 50°36′51″ N, 127°11′10″ W; Sayward [76]), from the Japan Sea and Pacific [77], from the Atlantic Coast in Norway [78], and from the coast of the White Sea in Russia [79]. All these additional samples were also collected during the reproductive season on breeding grounds.…”

Genetic basis and biotechnological manipulation of sexual dimorphism and sex determination in fish

“…In some cases, however, sex chromosomes are not the leader of sexual dimorphism, because quantitative genetic studies have observed discordance between sex chromosomes and phenotypic data [79]. Genetic architecture of threespine stickleback fish (Gasterosteus aculeatus) is very similar between males and females, but many traits show significant sexual difference, suggesting that genetic constraints for evolution of sex dimorphism might not be so severe and absolute as generally thought [80]. A great deal of data accumulation of the completely sequenced genomes, transcriptomes, and proteomics from model and farmed fishes provides a previous basis for us to explore the genetic and molecular mechanism of sex dimorphism [12].…”

“…Sexual dimorphism in fish not only includes size dimorphism, shape dimorphism and color dimorphism, but also comprises sexual differences in physiology and behavior [43,44]. Long-term field surveys and aquaculture practices have observed significant size dimorphism between male and female individuals in more than 20 fish species.…”

Sexual dimorphism in the feeding mechanism of threespine stickleback

“…Stickleback are known to exhibit sexual dimorphism in body shape and trophic morphology (Caldecutt and Adams, 1998;Kitano et al, 2007;Aguirre et al, 2008;Aguirre and Akinpelu, 2010;Leinonen et al, 2011). Additionally, males exhibit sex-specific behaviors involving the trophic apparatus (Stanley and Wootton, 1986).…”