Jossart Quentin, De Ridder Chantal, Lessios Harilaos A, Bauwens Mathieu, Motreuil Sébastien, Rigaud Thierry, Wattier Rémi A, David Bruno
Département de Biologie des Organismes Laboratoire de Biologie Marine Université Libre de Bruxelles (ULB) Brussels Belgium.
Biogéosciences UMR CNRS 6282 Université de Bourgogne Franche-Comté (UBFC) Dijon France.
Ecol Evol. 2017 Oct 4;7(22):9267-9280. doi: 10.1002/ece3.3413. eCollection 2017 Nov.
Evolution and population genetic structure of marine species across the Caribbean Sea are shaped by two complex factors: the geological history and the present pattern of marine currents. Characterizing and comparing the genetic structures of codistributed species, such as host-parasite associations, allow discriminating the relative importance of environmental factors and life history traits that influenced gene flow and demographic events. Using microsatellite and Cytochrome Oxidase I markers, we investigated if a host-parasite pair (the heart urchin and its parasitic pea crab ) exhibits comparable population genetic structures in the Caribbean Sea and how the observed patterns match connectivity regions from predictive models and other taxa. Highly contrasting patterns were found: the host showed genetic homogeneity across the whole studied area, whereas the parasite displayed significant differentiation at regional and local scales. The genetic diversity of the parasitic crabs (both in microsatellites and COI) was distributed in two main groups, Panama-Jamaica-St Croix on the one hand, and the South-Eastern Caribbean on the other. At a smaller geographical scale, Panamanian and Jamaican parasite populations were genetically more similar, while more genetic differentiation was found within the Lesser Antilles. Both species showed a signature of population expansion during the Quaternary. Some results match predictive models or data from previous studies (e.g., the Western-Eastern dichotomy in the parasite) while others do not (e.g., genetic differentiation within the Lesser Antilles). The sharp dissimilarity of genetic structure of these codistributed species outlines the importance of population expansion events and/or contrasted patterns of gene flow. This might be linked to differences in several life history traits such as fecundity (higher for the host), swimming capacity of larval stages (higher for the parasite), and habitat availability (higher for the host).
地质历史和当前的海流模式。对同域分布物种（如宿主 - 寄生虫组合）的遗传结构进行表征和比较，有助于区分影响基因流动和种群动态事件的环境因素和生活史特征的相对重要性。我们使用微卫星和细胞色素氧化酶I标记，研究了宿主 - 寄生虫对（心形海胆及其寄生的豌豆蟹）在加勒比海是否表现出可比的种群遗传结构，以及观察到的模式如何与预测模型和其他分类群的连通性区域相匹配。我们发现了截然不同的模式：宿主在整个研究区域内表现出遗传同质性，而寄生虫在区域和局部尺度上表现出显著的分化。寄生蟹的遗传多样性（微卫星和细胞色素氧化酶I方面）分布在两个主要群体中，一方面是巴拿马 - 牙买加 - 圣克罗伊，另一方面是加勒比海东南部。在较小的地理尺度上，巴拿马和牙买加的寄生虫种群在遗传上更为相似，而在小安的列斯群岛内部发现了更多的遗传分化。这两个物种在第四纪期间都表现出种群扩张的迹象。一些结果与预测模型或先前研究的数据相匹配（例如寄生虫的西 - 东二分法），而其他结果则不匹配（例如小安的列斯群岛内部的遗传分化）。这些同域分布物种遗传结构的显著差异凸显了种群扩张事件和/或不同基因流动模式的重要性。这可能与几种生活史特征的差异有关，如繁殖力（宿主更高）、幼虫阶段的游泳能力（寄生虫更高）和栖息地可用性（宿主更高）。
