Data from: Selection and sex-biased dispersal in a coastal shark: the influence of philopatry on adaptive variation

Sex-biased dispersal is expected to homogenize nuclear genetic variation relative to variation in genetic material inherited through the philopatric sex. When site fidelity occurs across a heterogeneous environment, local selective regimes may alter this pattern. We assessed spatial patterns of variation in nuclear-encoded, single nucleotide polymorphisms (SNPs) and sequences of the mitochondrial control region in bonnethead sharks (Sphyrna tiburo), a species thought to exhibit female philopatry, collected from summer habitats used for gestation. Geographic patterns of mtDNA haplotypes and putatively neutral SNPs confirmed female philopatry and male-mediated gene flow along the northeastern coast of the Gulf of Mexico. A total of 30 outlier SNP loci were identified; alleles at over half of these loci exhibited signatures of latitude-associated selection. Our results indicate that in species with sex-biased dispersal, philopatry can facilitate sorting of locally adaptive variation, with the dispersing sex facilitating movement of potentially adaptive variation among locations and environments.

相较于通过留居性别（philopatric sex）传递的遗传物质变异，性别偏倚扩散（sex-biased dispersal）理论上会促使核遗传变异趋于均一化。当异质环境中存在生境忠实性（site fidelity）时，局部选择机制可改变这一规律。我们以被认为具有雌性留居特性的窄头双髻鲨（Sphyrna tiburo）为研究对象，对其核编码单核苷酸多态性（single nucleotide polymorphisms, SNPs）及线粒体控制区序列的空间变异模式进行了评估，样本采集自该物种用于妊娠繁殖的夏季栖息生境。墨西哥湾东北沿岸的线粒体DNA单倍型与推定中性单核苷酸多态性位点的地理分布模式，证实了该物种的雌性留居特性及雄性介导的基因流。本研究共鉴定出30个异常SNP位点，其中超过半数位点的等位基因呈现出纬度关联选择的信号。研究结果显示，在存在性别偏倚扩散的物种中，留居性别可推动局部适应性变异的分选，而扩散性别则促进潜在适应性变异在不同区域与生境间的流通。