Taugbøl Annette, Arntsen Tina, Ostbye Kjartan, Vøllestad Leif Asbjørn
Centre for Ecological and Evolutionary Synthesis (CEES), Department of Biosciences, University of Oslo, Blindern, Norway.
Centre for Ecological and Evolutionary Synthesis (CEES), Department of Biosciences, University of Oslo, Blindern, Norway; Hedmark University College, Department of Forestry and Wildlife Management, Campus Evenstad, Elverum, Norway.
PLoS One. 2014 Sep 29;9(9):e106894. doi: 10.1371/journal.pone.0106894. eCollection 2014.
Salinity is one of the key factors that affects metabolism, survival and distribution of fish species, as all fish osmoregulate and euryhaline fish maintain osmotic differences between their extracellular fluid and either freshwater or seawater. The threespine stickleback (Gasterosteus aculeatus) is a euryhaline species with populations in both marine and freshwater environments, where the physiological and genomic basis for salinity tolerance adaptation is not fully understood. Therefore, our main objective in this study was to investigate gene expression of three targeted osmoregulatory genes (Na+/K+-ATPase (ATPA13), cystic fibrosis transmembrane regulator (CFTR) and a voltage gated potassium channel gene (KCNH4) and one stress related heat shock protein gene (HSP70)) in gill tissue from marine and freshwater populations when exposed to non-native salinity for periods ranging from five minutes to three weeks. Overall, the targeted genes showed highly plastic expression profiles, in addition the expression of ATP1A3 was slightly higher in saltwater adapted fish and KCNH4 and HSP70 had slightly higher expression in freshwater. As no pronounced changes were observed in the expression profiles of the targeted genes, this indicates that the osmoregulatory apparatuses of both the marine and landlocked freshwater stickleback population have not been environmentally canalized, but are able to respond plastically to abrupt salinity challenges.
盐度是影响鱼类新陈代谢、生存和分布的关键因素之一，因为所有鱼类都进行渗透压调节，广盐性鱼类维持其细胞外液与淡水或海水之间的渗透差异。三刺鱼（Gasterosteus aculeatus）是一种广盐性物种，在海洋和淡水环境中均有种群，但其耐盐性适应的生理和基因组基础尚未完全了解。因此，本研究的主要目的是调查来自海洋和淡水种群的鳃组织中三个靶向渗透压调节基因（Na+/K+-ATP酶（ATPA13）、囊性纤维化跨膜传导调节因子（CFTR）和一个电压门控钾通道基因（KCNH4））以及一个与应激相关的热休克蛋白基因（HSP70）在暴露于非原生盐度5分钟至3周期间的基因表达情况。总体而言，靶向基因显示出高度可塑性的表达谱，此外，ATP1A3在适应盐水的鱼类中的表达略高，而KCNH4和HSP70在淡水中的表达略高。由于在靶向基因的表达谱中未观察到明显变化，这表明海洋和内陆淡水三刺鱼种群的渗透压调节机制尚未受到环境的限制，而是能够对突然的盐度挑战做出可塑性反应。
