Nascimento-Schulze Jennifer C, Vajedsamiei Jahangir, Bean Tim P, Frankholz Lisa, Brennan Reid S, Melzner Frank, Ellis Robert P
Biosciences University of Exeter Exeter UK.
Research Division Marine Ecology GEOMAR Helmholtz Centre for Ocean Research Kiel Kiel Germany.
Evol Appl. 2025 Jun 19;18(6):e70118. doi: 10.1111/eva.70118. eCollection 2025 Jun.
Exploring evolutionary and physiological responses to environmental stress is crucial for assessing the effects of climate change on wild populations. Mussels, key inhabitants of the benthos with high ecological and economic value, are a particularly vulnerable species that may be pushed to their ecological limits as warming threatens their survival and population stability. Species within the complex are commonly found in temperate regions globally; in the Baltic Sea, populations are formed by and hybrids with low levels of introgression. This study investigates the mechanisms through which resilience towards global warming may be fast-tracked in Baltic mussels (Kiel, Germany). For this, we studied two cohorts of juvenile mussels (recently settled animals), one exposed to an extreme heat event early in life and one naïve to this stressor. Both cohorts were later exposed to experimental temperatures ranging from 21°C to 26°C, with animal performance measured after 25 days. Impacts of thermal stress on the genetic composition of each cohort was then assessed by genotyping 50 individuals using a blue mussel 60 K SNP-array. We observed a significant increase in genotypes together with a decrease in in the challenged cohort, compared to naive juveniles. We also found exposure to high temperature affected performance of mussel cohorts, reducing dry tissue weight of selected individuals. Results from this study provide insights on how selection through thermal stress impacts performance and genetic composition of key globally distributed intertidal species, with important implications for understanding and managing mussel populations under future warming scenarios.
探索对环境压力的进化和生理反应对于评估气候变化对野生种群的影响至关重要。贻贝是底栖生物的关键成员，具有很高的生态和经济价值，是一种特别脆弱的物种，随着气候变暖威胁到它们的生存和种群稳定性，它们可能会被推向生态极限。该复合体中的物种在全球温带地区普遍存在；在波罗的海，种群由 和 杂交种组成， 渗入水平较低。本研究调查了在波罗的海贻贝（德国基尔）中可能快速提升对全球变暖适应力的机制。为此，我们研究了两组幼年贻贝（刚定居的个体），一组在生命早期经历了极端高温事件，另一组未接触过这种压力源。两组贻贝随后都暴露在21°C至26°C的实验温度下，25天后测量动物的表现。然后通过使用蓝贻贝60K SNP阵列对50个个体进行基因分型，评估热应激对每组遗传组成的影响。与未接触过高温的幼年贻贝相比，我们观察到经历过高温的那组贻贝中 基因型显著增加， 基因型减少。我们还发现，暴露于高温会影响贻贝组的表现，降低选定个体的干组织重量。这项研究的结果为热应激选择如何影响全球主要分布的潮间带物种的表现和遗传组成提供了见解，对理解和管理未来变暖情景下的贻贝种群具有重要意义。
