Single and independent mutations lead to an adaptive and complex color phenotype in deer mice living on the light-colored soils of the Nebraska Sand Hills
Pleiotropy of genes is often the main solution to explain genetic basis of complex phenotypes (i.e., those composed of multiple traits). But dissection of those genes or loci are rarely studied, and it remains unclear which of single pleiotropic mutations or multiple mutations with independent effects are responsible to elaborate complex phenotypes. Linnen et al. are interested in coloration of the deer mice (Peromyscus maniculatus) present on the light-colored soils of the Nebraska Sand Hills. Adaptation for crypsis is the strongest hypothesis to explain prevalence of the light morph compared to the black morph, and they wanted to dissect the genetic basis of this adaptation. This study is composed of two main parts : first to understand and to evaluate the complexity of coloration phenotype and then to find the mutations responsible of those variation in traits and on which morph selection is acting on. First of all, they implemented an experimentation with plasticine models to count the number of attacks on each coloration morph. As they expected, statistical test reveals that the dark models are significantly more attacked than light models. Closer inspection reveals multiple pigmentation traits and pattern that differ between the light and the dark morph to compose complex coloration …
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