Lin Xiao-Nie, Hu Li-Sha, Chen Zhao-Hui, Dong Yun-Wei
The Key Laboratory of Mariculture, Ministry of Education, Fisheries College Ocean University of China Qingdao China.
Function Laboratory for Marine Fisheries Science and Food Production Processes Pilot National Laboratory for Marine Science and Technology Qingdao China.
Ecol Evol. 2023 Feb 22;13(2):e9843. doi: 10.1002/ece3.9843. eCollection 2023 Feb.
Macrobenthic invertebrates are ubiquitously distributed in the epipelagic zone of the open ocean. Yet, our understanding of their genetic structure patterns remains poorly understood. Investigating the genetic differentiation patterns of pelagic and clarifying the potential roles of temperature maintaining this pattern are crucial for our understanding of the distribution and biodiversity of pelagic macrobenthos. In the present study, mitochondrial cytochrome oxidase subunit I (mtDNA COI) from three South China Sea (SCS) populations and six Kuroshio Extension (KE) region populations of sampled from fixed buoys and genome-wide SNPs from a subset of populations (two SCS populations and four KE region populations) were sequenced and analyzed for investigating the genetic pattern of the pelagic barnacle. Water temperature was different among sampling sites; in other words, the water temperature decreased with latitude increases, and the water temperature on the surface was higher than in the subsurface. Our result showed that three lineages with clear genetic differentiation were found in different geographical locations and depths based on mtDNA COI, all SNPs, neutral SNPs, and outlier SNPs. Lineage 1 and lineage 2 were dominant in the subsurface populations and surface populations from the KE region, respectively. Lineage 3 was dominant in the SCS populations. Historical events during the Pliocene epoch shaped the differentiation of the three lineages, while, nowadays, temperature heterogeneity maintains the current genetic pattern of in the northwest Pacific. The subsurface populations were genetically isolated from the surface populations in the Kuroshio Extension (KE) region, implying small-scale vertical thermal heterogeneity was also an important factor maintaining the genetic differentiation pattern of the pelagic species.
大型底栖无脊椎动物广泛分布于开阔海洋的上层带。然而，我们对它们的遗传结构模式仍知之甚少。研究远洋生物的遗传分化模式并阐明温度维持这种模式的潜在作用，对于我们理解远洋大型底栖生物的分布和生物多样性至关重要。在本研究中，对从固定浮标采集的三个南海（SCS）种群和六个黑潮延伸区（KE）种群的线粒体细胞色素氧化酶亚基I（mtDNA COI）以及部分种群（两个SCS种群和四个KE区域种群）的全基因组单核苷酸多态性（SNPs）进行了测序和分析，以研究远洋藤壶的遗传模式。各采样点水温不同；也就是说，水温随纬度升高而降低，且表层水温高于次表层水温。我们的结果表明，基于mtDNA COI、所有SNPs、中性SNPs和异常SNPs，在不同地理位置和深度发现了三个具有明显遗传分化的谱系。谱系1和谱系2分别在KE区域的次表层种群和表层种群中占主导地位。谱系3在SCS种群中占主导地位。上新世时期的历史事件塑造了这三个谱系的分化，而如今，温度异质性维持了西北太平洋地区当前的遗传模式。在黑潮延伸区（KE），次表层种群与表层种群在遗传上相互隔离，这意味着小尺度的垂直热异质性也是维持远洋物种遗传分化模式的一个重要因素。
