Differential regulation of hsp70 genes in the freshwater key species Gammarus pulex (Crustacea, Amphipoda) exposed to thermal stress: effects of latitude and ontogeny
Differential regulation of hsp70 genes in the freshwater key species Gammarus pulex (Crustacea, Amphipoda) exposed to thermal stress: effects of latitude and ontogeny
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DOI：
10.1007/s00360-014-0885-1
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发表时间：
2015-04-01
影响因子：
2
通讯作者：
Piscart, Christophe
中科院分区：
文献类型：
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作者：
Cottin, Delphine;Foucreau, Natacha;Piscart, Christophe
温度是影响生物分布和丰度的主要非生物因子之一。在莱茵河流域，种群的甲壳类钩虾分布沿着5摄氏度的温度梯度从北到南的山谷。本文研究了G.根据纬度分布（北方与南方种群）和个体发育（成虫与早期胚胎）对蚤状蚤进行分类。我们分离了热休克蛋白70（HSP70）的两种异构体（一种组成型hsc70和一种诱导型hsp70），并利用实时PCR定量比较了热休克后它们的mRNA量。而hsc70（组成型）基因没有变化的两个群体之间，一个显着的效果的人口观察到的hsp70（诱导型）基因在成人标本中的表达。端足类动物的北方人口表现出更大的幅度的诱导和2 A度C较低的起始温度相比，南方人口，这表明北方人口是受温度升高的影响比南方的。热休克蛋白70的表达可能在G. pulex，因为它反映了该物种沿着纬度温度梯度的自然分布。hsc70基因的差异调节也观察到根据个体发育阶段，与开关从热诱导在生命早期阶段的组成型和高表达的成年人。这些研究结果表明，考虑整个生命周期，以更好地了解热应力的适应性反应的重要性。
Temperature is one of the main abiotic factors influencing the distribution and abundance of organisms. In the Rhne River Valley, populations of the crustacean Gammarus pulex are distributed along a 5 A degrees C thermal gradient from the North to the South of the valley. In this present work, we investigated the heat shock response of G. pulex according to latitudinal distribution (northern vs. southern populations) and ontogeny (adults vs. embryos from early stages). We isolated two isoforms (one constitutive hsc70 and one inducible hsp70) of heat shock proteins 70 (HSP70) and quantitatively compared their amounts of mRNA after heat shocks, using real-time PCR. Whereas the hsc70 (constitutive) gene did not vary between the two populations, a significant effect of the population was observed on the expression of the hsp70 (inducible) gene in adult specimens. The northern population of amphipods showed a greater magnitude of induction and a 2 A degrees C lower onset temperature when compared to the southern population, suggesting that the northern population is more affected by elevated temperature than the southern one. We demonstrated that the expression of hsp70 may play a crucial role in the persistence of biogeographical patterns of G. pulex, since it reflects the natural distribution of this species along the latitudinal thermal gradient. A differential regulation of hsc70 gene was also observed according to the ontogenetic stage, with a switch from heat inducible in early life stages to constitutively and highly expressed in adults. These findings demonstrate the importance of considering the entire life cycle to better understand the adaptive response to thermal stress.