MOE Key Laboratory of Marine Genetics and Breeding, College of Marine Life Sciences, Ocean University of China, Qingdao, China; Academy of Future Ocean, Ocean University of China, Qingdao, China.
MOE Key Laboratory of Marine Genetics and Breeding, College of Marine Life Sciences, Ocean University of China, Qingdao, China.
Genomics. 2024 Sep;116(5):110904. doi: 10.1016/j.ygeno.2024.110904. Epub 2024 Jul 29.
Recently, elevated seawater temperatures have resulted numerous adverse effects, including significant mortality among bivalves. The dwarf surf clam, Mulinia lateralis, is considered a valuable model species for bivalve research due to its rapid growth and short generation time. The successful cultivation in laboratory setting throughout its entire life cycle makes it an ideal candidate for exploring the potential mechanisms underlying bivalve responses to thermal stress. In this study, a total of 600 clams were subjected to a 17-day thermal stress experiment at a temperature of 30 °C which is the semi-lethal temperature for this species. Ninety individuals who perished initially were classified as heat-sensitive populations (HSP), while 89 individuals who survived the experiment were classified as heat-tolerant populations (HTP). Subsequently, 179 individuals were then sequenced, and 21,292 single nucleotide polymorphisms (SNPs) were genotyped for downstream analysis. The heritability estimate for survival status was found to be 0.375 ± 0.127 suggesting a genetic basis for thermal tolerance trait. Furthermore, a genome-wide association study (GWAS) identified three SNPs and 10 candidate genes associated with thermal tolerance trait in M. lateralis. These candidate genes were involved in the ETHR/EHF signaling pathway and played pivotal role in signal sensory, cell adhesion, oxidative stress, DNA damage repair, etc. Additionally, qPCR results indicated that, excluding MGAT4A, ZAN, and RFC1 genes, all others exhibited significantly higher expression in the HTP (p < 0.05), underscoring the critical involvement of the ETHR/EHF signaling pathway in M. lateralis' thermal tolerance. These results unveil the presence of standing genetic variations associated with thermal tolerance in M. lateralis, highlighting the regulatory role of the ETHR/EHF signaling pathway in the bivalve's response to thermal stress, which contribute to comprehension of the genetic basis of thermal tolerance in bivalves.
最近，海水温度升高导致了许多不良影响，包括双壳类动物的大量死亡。矮滨螺（Mulinia lateralis）因其生长迅速和世代时间短，被认为是双壳类研究的有价值的模式物种。在实验室环境中成功养殖其整个生命周期，使其成为探索双壳类动物对热应激反应潜在机制的理想候选物种。在这项研究中，总共 600 只蛤在 30°C 的温度下进行了为期 17 天的热应激实验，该温度是该物种的半致死温度。最初死亡的 90 只被归类为热敏种群（HSP），而在实验中存活的 89 只被归类为耐热种群（HTP）。随后，对 179 只个体进行了测序，共鉴定出 21292 个单核苷酸多态性（SNP）用于下游分析。存活状态的遗传力估计值为 0.375±0.127，表明耐热性状具有遗传基础。此外，全基因组关联研究（GWAS）在矮滨螺中发现了与耐热性状相关的三个 SNP 和 10 个候选基因。这些候选基因参与 ETHR/EHF 信号通路，并在信号感应、细胞黏附、氧化应激、DNA 损伤修复等方面发挥关键作用。此外，qPCR 结果表明，除了 MGAT4A、ZAN 和 RFC1 基因外，其他所有基因在 HTP 中的表达水平均显著升高（p<0.05），这表明 ETHR/EHF 信号通路在矮滨螺耐热性中起着至关重要的作用。这些结果揭示了矮滨螺中与耐热性相关的遗传变异的存在，强调了 ETHR/EHF 信号通路在双壳类动物对热应激反应中的调节作用，有助于理解双壳类动物耐热性的遗传基础。
