Data from: Non-clonal coloniality: genetically chimeric colonies through fusion of sexually produced polyps in the hydrozoan Ectopleura larynx

Hydrozoans typically develop colonies through asexual budding of polyps. Although colonies of Ectopleura are similar to other hydrozoans in that they consist of multiple polyps physically connected through continuous epithelia and shared gastrovascular cavity, Ectopleura larynx does not asexually bud polyps indeterminately. Instead, after an initial phase of limited budding in a young colony, E. larynx achieves its large colony size through the aggregation and fusion of sexually (non-clonally) produced polyps. The apparent chimerism within a physiologically integrated colony presents a potential source of conflict between distinct genetic lineages, which may vary in their ability to access the germline. In order to determine the extent to which the potential for genetic conflict exists, we characterized the types of genetic relationships between polyps within colonies, using a RAD-Seq approach. Our results indicate that E. larynx colonies are indeed comprised of polyps that are clones and sexually reproduced siblings and offspring, consistent with their life history. In addition, we found that colonies also contain polyps that are genetically unrelated, and that estimates of genome-wide relatedness suggests a potential for conflict within a colony. Taken together, our data suggests that there are distinct categories of relationships in colonies of E. larynx, likely achieved though a range of processes including budding, regeneration and fusion of progeny and unrelated polyps, with the possibility for a genetic conflict resolution mechanism. Together these processes contribute to the re-evolution of the ecologically important trait of coloniality in E. larynx.水螅虫类（Hydrozoans）通常通过水螅体的无性出芽形成生物群体。尽管外螅属（Ectopleura）的群体与其他水螅虫类类似，均由多个通过连续上皮组织与共享消化循环腔物理连接的水螅体构成，但喉外螅（Ectopleura larynx）并不会无限制地无性出芽产生水螅体。与之相反，在幼体群体经历有限出芽的初始阶段后，喉外螅通过有性（非克隆）产生的水螅体的聚集与融合来实现群体的大规模生长。生理整合的群体内部所呈现的表观嵌合现象，为不同遗传谱系间的冲突埋下了潜在可能——这些谱系在获取生殖系的能力上可能存在差异。为明确遗传冲突潜在可能性的程度，我们采用RAD测序（RAD-Seq）技术，对群体内各水螅体间的遗传关系类型进行了表征。研究结果表明，喉外螅的群体确实由克隆水螅体、有性繁殖的同胞姊妹体及子代水螅体构成，这与其生活史特征相符。此外，我们还发现群体内同时存在遗传上无关联的水螅体，而全基因组亲缘关系估算结果显示，群体内部存在发生遗传冲突的潜在可能。综合来看，我们的数据表明喉外螅群体内存在多种不同类型的遗传关系，这可能通过一系列过程实现，包括出芽、再生以及子代与无关联水螅体的融合，同时群体内可能存在遗传冲突的调控机制。上述这些过程共同推动了喉外螅群体生活这一具有重要生态意义的性状的重新演化。