Data from: Asynchronous spawning in sympatric populations of a hard coral reveals cryptic species and ancient genetic lineages

Genetic subdivision within a species is a vital component of the evolution of biodiversity. In some species of Acropora corals in Western Australia, conspecific individuals spawn in two seasons 6 months apart, which has the potential to impede gene flow and result in genetic divergence. Genetic comparison of sympatric spring and autumn spawners of Acropora samoensis was conducted to assess the level of reproductive isolation and genetic divergence between the spawning groups based on multiple loci (13 microsatellite loci, the mitochondrial control region and two nuclear introns). Bayesian clustering and principal coordinate analysis of the microsatellite loci showed a high level of genetic differentiation between the spawning groups (F’ST = 0.30; P < 0.001), as did the sequence data from PaxC and Calmodulin (ΦST = 0.97 and 0.31, respectively). At the PaxC locus, the autumn and spring spawners were associated with two divergent lineages that were separated by an evolutionary distance of 1.7% and statistical tests indicate divergent selection in PaxC, suggesting this gene may play a role in coral spawning. This study indicates that the autumn and spring spawners represent two cryptic species, and highlights the importance of asynchronous spawning as a mechanism influencing speciation in corals.物种内的遗传分化是生物多样性演化的核心组成部分。西澳大利亚海域的部分轴孔珊瑚属（Acropora）珊瑚中，同种个体在间隔6个月的两个季节产卵，该现象可能阻碍基因交流并引发遗传分化。本研究针对萨摩亚轴孔珊瑚（Acropora samoensis）的同域春季产卵群体与秋季产卵群体开展遗传比较，基于多类分子标记位点（13个微卫星位点、线粒体控制区及两个核内含子），评估不同产卵群体间的生殖隔离程度与遗传分化水平。对微卫星位点的贝叶斯聚类分析与主坐标分析结果显示，不同产卵群体间存在高度遗传分化（F’ST=0.30；P<0.001）；PaxC基因与钙调蛋白（Calmodulin）基因的序列数据亦得到一致结果（ΦST分别为0.97与0.31）。在PaxC基因位点上，秋季与春季产卵群体分别隶属于两个分化的演化支系，二者间的演化距离达1.7%；统计学检验显示PaxC基因存在歧化选择，提示该基因可能参与珊瑚产卵的调控过程。本研究表明，春季与秋季产卵的群体实为两个隐存种，并凸显了异步产卵作为影响珊瑚物种形成的关键机制的重要性。