Jesus Tiago F, Moreno João M, Repolho Tiago, Athanasiadis Alekos, Rosa Rui, Almeida-Val Vera M F, Coelho Maria M
Centro de Ecologia Evolução e Alterações Ambientais, Faculdade de Ciências, Universidade de Lisboa, Lisboa, Portugal.
Laboratório Marítimo da Guia, MARE-Centro de Ciências do Mar e do Ambiente, Faculdade de Ciências da Universidade de Lisboa, Av. Nossa Senhora do Cabo, Cascais, Portugal.
PLoS One. 2017 Jul 18;12(7):e0181325. doi: 10.1371/journal.pone.0181325. eCollection 2017.
Current knowledge on the biological responses of freshwater fish under projected scenarios of climate change remains limited. Here, we examine differences in the protein configuration of two endemic Iberian freshwater fish species, Squalius carolitertii and the critically endangered S. torgalensis that inhabit in the Atlantic-type northern and in the Mediterranean-type southwestern regions, respectively. We performed protein structure modeling of fourteen genes linked to protein folding, energy metabolism, circadian rhythms and immune responses. Structural differences in proteins between the two species were found for HSC70, FKBP52, HIF1α and GPB1. For S. torgalensis, besides structural differences, we found higher thermostability for two proteins (HSP90 and GBP1), which can be advantageous in a warmer environment. Additionally, we investigated how these species might respond to projected scenarios of 3° climate change warming, acidification (ΔpH = -0.4), and their combined effects. Significant changes in gene expression were observed in response to all treatments, particularly under the combined warming and acidification. While S. carolitertii presented changes in gene expression for multiple proteins related to folding (hsp90aa1, hsc70, fkbp4 and stip1), only one such gene was altered in S. torgalensis (stip1). However, S. torgalensis showed a greater capacity for energy production under both the acidification and combined scenarios by increasing cs gene expression and maintaining ldha gene expression in muscle. Overall, these findings suggest that S. torgalensis is better prepared to cope with projected climate change. Worryingly, under the simulated scenarios, disturbances to circadian rhythm and immune system genes (cry1aa, per1a and gbp1) raise concerns for the persistence of both species, highlighting the need to consider multi-stressor effects when evaluating climate change impacts upon fish. This work also highlights that assessments of the potential of endangered freshwater species to cope with environmental change are crucial to help decision-makers adopt future conservation strategies.
目前，关于气候变化预测情景下淡水鱼生物学反应的知识仍然有限。在此，我们研究了两种伊比利亚特有淡水鱼——分别栖息在大西洋型北部地区的卡罗利特斯氏鲤（Squalius carolitertii）和极度濒危的托尔加利斯氏鲤（S. torgalensis），后者栖息在地中海型西南部地区——蛋白质结构的差异。我们对与蛋白质折叠、能量代谢、昼夜节律和免疫反应相关的14个基因进行了蛋白质结构建模。发现两种鱼之间的热休克蛋白70（HSC70）、FK506结合蛋白52（FKBP52）、缺氧诱导因子1α（HIF1α）和甘油醛-3-磷酸脱氢酶B1（GPB1）存在蛋白质结构差异。对于托尔加利斯氏鲤，除了结构差异外，我们还发现两种蛋白质（热休克蛋白90（HSP90）和甘油醛-3-磷酸脱氢酶B1（GBP1））具有更高的热稳定性，这在温暖环境中可能具有优势。此外，我们研究了这些物种对预计3℃的气候变暖、酸化（ΔpH = -0.4）及其综合影响的情景可能会如何反应。在所有处理下均观察到基因表达的显著变化，特别是在变暖与酸化的综合作用下。虽然卡罗利特斯氏鲤呈现出与折叠相关的多种蛋白质（热休克蛋白90αa1（hsp90aa1）、热休克蛋白70（hsc70）、FK506结合蛋白4（fkbp4）和应激诱导磷蛋白1（stip1））的基因表达变化，但托尔加利斯氏鲤中只有一个这样的基因（应激诱导磷蛋白1（stip1））发生了改变。然而，在酸化和综合情景下，托尔加利斯氏鲤通过增加细胞色素c氧化酶基因（cs）表达并维持肌肉中乳酸脱氢酶A基因（ldha）表达，表现出更强的能量产生能力。总体而言，这些发现表明托尔加利斯氏鲤更有能力应对预计的气候变化。令人担忧的是，在模拟情景下，昼夜节律和免疫系统基因（隐花色素1aa（cry1aa）、周期蛋白1a（per1a）和甘油醛-3-磷酸脱氢酶B1（gbp1））受到干扰，这引发了对这两个物种存续的担忧，凸显了在评估气候变化对鱼类的影响时考虑多胁迫效应的必要性。这项工作还强调，评估濒危淡水物种应对环境变化的潜力对于帮助决策者制定未来的保护策略至关重要。
