Multiple genetic sources facilitate the northward range expansion of an intertidal oyster along China's coast

• Published in: Ecological applications 2024-01, Vol.34 (1), p.e2764-n/a
• Main Authors: Hu, Li‐Sha, Dong, Yun‐Wei
• Format: Article
• Language: English
• Subjects: Adaptability; adaptation; Animals; Biodiversity; biogeographic barrier; biological invasion; Coastal structures; Crassostrea - genetics; dispersal pathway; DNA sequencing; Ecosystem; Estuaries; Gene flow; Gene polymorphism; Genetic diversity; genetic sources; Genotypes; Geographical distribution; Habitat availability; Heat; Heat stress; Heat tolerance; Invasive species; Larva; Larvae; Mud flats; Nucleotides; Oysters; Polymorphism; population connectivity; Population genetics; Population structure; Populations; Range extension; Redundancy; Single-nucleotide polymorphism; Substrates; Wildlife conservation
• ISSN: 1051-0761; 1939-5582
• DOI: 10.1002/eap.2764

Coastal artificial structures on the former mudflats provide available habitats for the rocky intertidal species which can establish new populations in these emerging habitats over their former distribution range limits. As a former southern species, the oyster Crassostrea sikamea has become a pioneer and rapidly invaded the artificial shorelines in northern China. We used a seascape genomics approach to investigate the population structure and genetic sources of C. sikamea on the coastal artificial structures, which is crucial for understanding the genetic mechanisms driving species distribution range expansion and invasion pathway of intertidal species. Five C. sikamea populations, including two artificial substrate populations (WGZ and ZAP), one oyster reef population (LS), and two natural rocky shore populations (ZS and XM), were measured using single nucleotide polymorphism (SNPs) obtained from double digest restriction‐site associated DNA sequencing (ddRAD‐Seq). Redundancy analyses (RDA) were implemented for investigating the relationship between local temperature variables and the temperature adaptability of C. sikamea. Genetic diversity, direction and strength of gene flow, and population structure all revealed that the LS and ZS populations were the genetic sources for the oyster populations on the emerging northern coastal artificial structures. Results of RDA showed that there were different adaptive potentials for northern and southern populations to local temperature variables and the oyster reef population which frequently suffers from heat stress owned high heat adaptability. The ZS population as a genetic source nearby the Yangtze River estuary provided mass larvae for the northern populations, and the other genetic source, the heat‐tolerant LS population, in the oyster reef played an important role in the post‐settlement success by providing preadapted genotypes. These results highlight the importance of multiple sources with divergent adaptative capabilities for biological invasion, and also emphasize the importance of the oyster reef in coastal biodiversity and conservation. 摘要 潮滩上人工建筑物构建为潮间带岩相物种提供了适合的附着基质，使其能够跨越原有地理分布隔离，在新生境中建立种群。南方物种熊本牡蛎 (Crassostrea sikamea) 正迅速入侵中国北方人工海岸线，目前已成为江苏沿岸人工海岸线上的优势种。本研究采用景观基因组学 (seascape genomics) 方法对潮间带人工基质上熊本牡蛎种群结构和遗传来源进行了研究，以解析潮间带物种分布范围扩张的遗传机制和入侵途径。利用双酶切限制性位点测序 (ddRAD‐Seq) 获得2个人工基质种群 (WGZ和ZAP)、1个牡蛎礁种群 (LS) 和2个自然岩相种群 (ZS和XM) 的单核苷酸多态位点 (SNPs)，并采用冗余分析 (RDA) 研究了环境温度与熊本牡蛎种群温度适应性之间的关系。遗传多样性、基因流动方向和强度以及种群遗传结构等研究