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Abstract：
Resolving the genomic basis underlying phenotypic variations is a question of great importance in evolutionary biology. However, understanding how genotypes determine the phenotypes is still challenging. Centuries of artificial selective breeding for beauty and aggression resulted in a plethora of colors, long-fin varieties, and hyper-aggressive behavior in the air-breathing Siamese fighting fish (Betta splendens), supplying an excellent system for studying the genomic basis of phenotypic variations. Combining whole-genome sequencing, quantitative trait loci mapping, genome-wide association studies, and genome editing, we investigated the genomic basis of huge morphological variation in fins and striking differences in coloration in the fighting fish. Results revealed that the double tail, elephant ear, albino, and fin spot mutants each were determined by single major-effect loci. The elephant ear phenotype was likely related to differential expression of a potassium ion channel gene, kcnh8. The albinotic phenotype was likely linked to a cis-regulatory element acting on the mitfa gene and the double-tail mutant was suggested to be caused by a deletion in a zic1/zic4 coenhancer. Our data highlight that major loci and cis-regulatory elements play important roles in bringing about phenotypic innovations and establish Bettas as new powerful model to study the genomic basis of evolved changes.
摘要：
解决表型变异的基因组基础是进化生物学中非常重要的问题。然而,理解基因型如何决定表型仍然具有挑战性。几个世纪的人工选择育种的美丽和侵略导致了过多的颜色，长鳍品种，和呼吸连体斗鱼（Bettasplendens）的超攻击性行为，为研究表型变异的基因组基础提供了一个极好的系统。结合全基因组测序，数量性状基因座定位，全基因组关联研究，和基因组编辑，我们调查了鳍的巨大形态变异和战斗鱼颜色差异的基因组基础。结果显示，双尾，大象耳朵,白化病,鳍点突变体分别由单个主要效应基因座确定。象耳表型可能与钾离子通道基因的差异表达有关，kcnh8.白化病表型可能与作用于mitfa基因的顺式调节元件有关，并且双尾突变体被认为是由zic1/zic4共增强子中的缺失引起的。我们的数据突出表明，主要基因座和顺式调控元件在实现表型创新方面发挥着重要作用，并将Bettas建立为研究进化变化的基因组基础的新的强大模型。
