Data accompanying Polyphenisms and polymorphisms: genetic variation in plasticity and color variation within and among bluefin killifish populations

The presence of stable color polymorphisms within populations begs the question of how genetic variation is maintained. Consistent variation among populations in coloration, especially when correlated with environmental variation, raises questions about whether environmental conditions affect either the fulcrum of those balanced polymorphisms, the plastic expression of coloration, or both. Color patterns in male bluefin killifish provoke both types of questions. Red and yellow morphs are common in all populations. Blue males are more common in tannin-stained swamps relative to clear springs. Here we combined crosses with a manipulation of light to explore how genetic variation and phenotypic plasticity shape these patterns. We found that the variation in coloration is attributable mainly to two axes of variation: (1) a red-yellow axis with yellow being dominant to red, and (2) a blue axis that can override red-yellow and is controlled by genetics, phenotypic plasticity, and genetic variation for phenotypic plasticity. The variation among populations in plasticity suggests it is adaptive in some populations but not others. The variation among sires in plasticity within the swamp population suggests balancing selection may be acting not only on the red-yellow polymorphism but also on plasticity for blue coloration.

种群内稳定存在的色彩多态性（stable color polymorphisms）引发了一个核心科学疑问：遗传变异究竟如何得以维持。而种群间稳定存在的色彩差异——尤其当该差异与环境变化相关联时——更催生了新的思考：环境条件是否会影响这些平衡多态性的调控支点、色彩的表型可塑性（phenotypic plasticity）表达，抑或是同时影响二者？雄性蓝鳍鳉的色彩模式恰好同时引发了这两类疑问。红、黄两种色型在所有种群中均较为常见；相较于清澈的泉水生境，被单宁染色的沼泽生境中蓝色雄性的占比更高。本研究结合杂交实验与光照操控手段，探究遗传变异与表型可塑性如何塑造上述色彩模式。研究结果显示，色彩差异主要可归因于两个变异维度：其一为红-黄维度，黄色对红色呈显性；其二为蓝色维度，该维度可凌驾于红-黄维度之上，其调控涉及遗传因素、表型可塑性以及表型可塑性相关的遗传变异。种群间的可塑性差异提示，表型可塑性在部分种群中具有适应性意义，而在另一部分种群中则不然。沼泽种群内父本间的可塑性差异则表明，平衡选择可能不仅作用于红-黄色多态性，同时也作用于蓝色色彩的表型可塑性。