Data from: Genome-wide association mapping in a wild avian population identifies a link between genetic and phenotypic variation in a life-history trait

Understanding the genetic basis of traits involved in adaptation is a major challenge in evolutionary biology but remains poorly understood. Here, we use genome-wide association mapping using a custom 50 k single nucleotide polymorphism (SNP) array in a natural population of collared flycatchers to examine the genetic basis of clutch size, an important life-history trait in many animal species. We found evidence for an association on chromosome 18 where one SNP significant at the genome-wide level explained 3.9% of the phenotypic variance. We also detected two suggestive quantitative trait loci (QTLs) on chromosomes 9 and 26. Fitness differences among genotypes were generally weak and not significant, although there was some indication of a sex-by-genotype interaction for lifetime reproductive success at the suggestive QTL on chromosome 26. This implies that sexual antagonism may play a role in maintaining genetic variation at this QTL. Our findings provide candidate regions for a classic avian life-history trait that will be useful for future studies examining the molecular and cellular function of, as well as evolutionary mechanisms operating at, these loci.解析适应性相关性状的遗传基础是进化生物学领域的核心难题之一，目前相关认知仍较为匮乏。本研究针对自然种群中的领姬鹟，利用定制化50k单核苷酸多态性（single nucleotide polymorphism, SNP）芯片开展全基因组关联分析，以解析窝卵数的遗传基础——窝卵数是诸多动物类群中一项关键的生活史性状。研究在18号染色体上发现了显著关联信号：1个达到全基因组显著性水平的SNP可解释3.9%的表型变异。此外，本研究还在9号及26号染色体上检测到2个提示性数量性状位点（quantitative trait locus, QTL）。不同基因型间的适合度差异整体较弱且无统计学显著性，但在26号染色体的提示性QTL处，存在性别与基因型互作影响终生繁殖成功率的初步迹象。这提示，性拮抗作用可能在维持该QTL的遗传变异中发挥作用。本研究的结果为这一经典鸟类生活史性状找到了候选关联区域，可为后续探究这些位点的分子与细胞功能，以及其背后的进化机制提供重要参考。