Centro de Biologia Ambiental, Faculdade de Ciências, Universidade de Lisboa, Campo Grande, Lisbon, Portugal.
Genet Mol Biol. 2013 Mar;36(1):61-9. doi: 10.1590/S1415-47572013000100009. Epub 2013 Mar 4.
Comprehension of the mechanisms by which ectotherms, such as fish, respond to thermal stress is paramount for understanding the threats that environmental changes may pose to wild populations. Heat shock proteins are molecular chaperones with an important role in several stress conditions such as high temperatures. In the Iberian Peninsula, particularly in Portugal, freshwater fish of the genus Squalius are subject to daily and seasonal temperature variations. To examine the extent to which different thermal regimes influence the expression patterns of hsp70 and hsc70 transcripts we exposed two species of Squalius (S. torgalensis and S. carolitertii) to different temperatures (20, 25, 30 and 35 °C). At 35 °C, there was a significant increase in the expression of hsp70 and hsc70 in the southern species, S. torgalensis, while the northern species, S. carolitertii, showed no increase in the expression of these genes; however, some individuals of the latter species died when exposed to 35 °C. These results suggest that S. torgalensis may cope better with harsher temperatures that are characteristic of this species natural environment; S. carolitertii, on the other hand, may be unable to deal with the extreme temperatures faced by the southern species.
理解变温动物（如鱼类）对热应激的反应机制对于了解环境变化可能对野生种群造成的威胁至关重要。热休克蛋白是分子伴侣，在高温等多种应激条件下发挥着重要作用。在伊比利亚半岛，特别是在葡萄牙，鱲属的淡水鱼类受到日常和季节性温度变化的影响。为了研究不同的热环境对 hsp70 和 hsc70 转录本表达模式的影响程度，我们将两种鱲属鱼类（S. torgalensis 和 S. carolitertii）暴露于不同温度（20、25、30 和 35°C）下。在 35°C 时，南部物种 S. torgalensis 的 hsp70 和 hsc70 的表达显著增加，而北部物种 S. carolitertii 的这些基因表达没有增加；然而，后者的一些个体在暴露于 35°C 时死亡。这些结果表明，S. torgalensis 可能更能适应其自然环境中特有的更严酷温度；另一方面，S. carolitertii 可能无法应对南部物种所面临的极端温度。
