Lalouette Auréline, Chaumot Arnaud, Lepeule Louveline, Gaget Karen, Delorme Nicolas, Garnero Laura, Calevro Federica, Esposti Davide Degli
Laboratoire d'écotoxicologie, INRAE, UR RiverLy, Villeurbanne, 69625, France.
INRAE, INSA Lyon, Université de Lyon, BF2i, UMR 203, Villeurbanne, 69621, France.
Sci Rep. 2025 Apr 22;15(1):13913. doi: 10.1038/s41598-025-98937-6.
The metallothionein gene family codes for proteins involved in metal homeostasis and acute detoxification of non-essential toxic metal ions across the tree of life. We have previously documented increased cadmium (Cd) tolerance in field populations of the crustacean Gammarus fossarum exposed to chronic metallic contamination of geochemical origin. This tolerance is lost during maintenance of organisms in the laboratory, and is transmitted to offspring via parental effects. This study investigated whether the expression of the Cd-responsive metallothionein gene mt1 could be related to Cd-tolerance plasticity in G. fossarum. In eleven populations with different chronic Cd exposure history, we simultaneously assessed Cd-tolerance (mortality tests) and G. fossarum mt1 expression levels by RT-qPCR in the gills and caeca of adult males and in neonates. mt1 expression levels in the two organs were correlated to Cd-tolerance in field organisms and a loss of tolerance was observed in parallel with a decreased expression of mt1 in the caeca after maintenance in uncontaminated water. We also recorded a greater inducibility of mt1 expression in offspring of tolerant populations in the laboratory when re-exposed to Cd along with the bi-parental transmission of Cd-tolerance. These results suggest that the control of mt1 expression is involved in the plasticity of Cd-tolerance in gammarid populations with different histories of Cd exposure.
金属硫蛋白基因家族编码的蛋白质参与了整个生命树中金属稳态的维持以及非必需有毒金属离子的急性解毒过程。我们之前记录到，在受到地球化学来源的慢性金属污染的甲壳动物河蚬野外种群中，镉（Cd）耐受性增强。这种耐受性在实验室饲养过程中会丧失，并且会通过亲代效应传递给后代。本研究调查了镉响应性金属硫蛋白基因mt1的表达是否与河蚬的镉耐受性可塑性有关。在11个具有不同慢性镉暴露历史的种群中，我们同时通过实时定量PCR评估了成年雄性个体以及幼体在鳃和盲肠中的镉耐受性（死亡率测试）和河蚬mt1的表达水平。在野外生物中，这两个器官中的mt1表达水平与镉耐受性相关，并且在未受污染的水中饲养后，观察到耐受性丧失的同时盲肠中mt1的表达也降低。我们还记录到，在实验室中，耐受种群的后代在再次暴露于镉时，mt1表达的诱导性更强，同时镉耐受性也会双亲遗传。这些结果表明，mt1表达的调控参与了具有不同镉暴露历史的钩虾种群中镉耐受性的可塑性。
