Melroy Laura M, Cohen C Sarah
Department of Biology Estuary & Ocean Science Center San Francisco State University Tiburon CA USA.
Ecol Evol. 2021 Mar 4;11(7):3313-3331. doi: 10.1002/ece3.7283. eCollection 2021 Apr.
Temporal genetic studies of low-dispersing organisms are rare. Marine invertebrates lacking a planktonic larval stage are expected to have lower dispersal, low gene flow, and a higher potential for local adaptation than organisms with planktonic dispersal. is a genus of brooding sea stars containing several cryptic species complexes. Population genetic methods were used to resolve patterns of fine-scale population structure in central California species using three loci from nuclear and mitochondrial genomes. Historic samples (collected between 1897 and 1998) were compared to contemporary samples (collected between 2008 and 2014) to delineate changes in species distributions in space and time. Phylogenetic analysis of contemporary samples confirmed the presence of a bay-localized clade and revealed the presence of an additional bay-localized and previously undescribed clade of . Analysis of contemporary and historic samples indicates two clades are experiencing a constriction in their southern range limit and suggests a decrease in clade-specific abundance at sites at which they were once prevalent. Historic sampling revealed a dramatically different distribution of diversity along the California coastline compared to contemporary sampling and illustrates the importance of temporal genetic sampling in phylogeographic studies. These samples were collected prior to significant impacts of Sea Star Wasting Disease (SSWD) and represent an in-depth analysis of genetic structure over 117 years prior to the SSWD-associated mass die-off of .
对低扩散生物的时间遗传研究很少见。与具有浮游扩散的生物相比，缺乏浮游幼虫阶段的海洋无脊椎动物预计具有更低的扩散率、低基因流以及更高的局部适应潜力。 是一类孵育型海星，包含几个隐存物种复合体。利用核基因组和线粒体基因组的三个基因座，采用群体遗传方法解析加利福尼亚中部 物种的精细尺度群体结构模式。将历史样本（1897年至1998年收集）与当代样本（2008年至2014年收集）进行比较，以描绘物种在空间和时间上分布的变化。对当代样本的系统发育分析证实了一个海湾定位分支的存在，并揭示了另一个海湾定位且先前未描述的 分支的存在。对当代和历史样本的分析表明，两个分支在其南部范围界限正经历收缩，并表明在它们曾经普遍存在的地点，特定分支的丰度有所下降。历史采样显示，与当代采样相比，加利福尼亚海岸线沿线的多样性分布有显著差异，并说明了时间遗传采样在系统地理学研究中的重要性。这些样本是在海星消瘦病（SSWD）产生重大影响之前收集的，代表了在SSWD相关的 大规模死亡事件发生前117年对遗传结构的深入分析。
