College of Life Sciences, Zhejiang Normal University, Jinhua 321004, China.
Department of Biology, Carleton University, Ottawa, ON K1S5B6, Canada.
Int J Mol Sci. 2024 Oct 2;25(19):10637. doi: 10.3390/ijms251910637.
Continual climate change strongly influences temperature conditions worldwide, making ectothermic animals as suitable species for studying the potential impact of climate change on global biodiversity. However, the study of how lizards distributed at different latitudes respond to climate change at the transcriptome level is still insufficient. According to the Climatic Variability Hypothesis (CVH), the range of climate fluctuations experienced by terrestrial animals throughout the year increases with latitude, so individuals at higher latitudes should exhibit greater thermal plasticity to cope with fluctuating environments. Mitochondria, as the energy center of vertebrate cells, may indicate species' plasticity through the sensitivity of gene expression. In this study, we focused on the changes in transcript levels of liver mitochondrial protein-coding genes (PCGs) in skinks from the genus ( and ) and the genus ( and ) under low-temperature conditions of 8 °C, compared to the control group at 25 °C. Species within the same genus of skinks exhibit different latitudinal distribution patterns. We found that the two species, and , employ a metabolic depression strategy (decreased transcript levels) to cope with low temperatures. In contrast, the two species show markedly different patterns: exhibits significant increases in the transcript levels of six genes (metabolic compensation), while in , only two mitochondrial genes are downregulated (metabolic depression) compared to the control group. We also found that and , which live at mid-to-high latitudes, exhibit stronger adaptive responses and plasticity at the mitochondrial gene level compared to and , which live at lower latitudes. We suggest that this enhanced adaptability corresponds to more significant changes in a greater number of genes (plasticity genes).
持续的气候变化强烈影响着全球的温度条件，使变温动物成为研究气候变化对全球生物多样性潜在影响的合适物种。然而，关于分布在不同纬度的蜥蜴如何在转录组水平上响应气候变化的研究还不够充分。根据气候可变性假说（CVH），陆生动物全年经历的气候波动范围随着纬度的增加而增加，因此高纬度地区的个体应该表现出更大的热塑性，以应对波动的环境。线粒体作为脊椎动物细胞的能量中心，其基因表达的敏感性可能表明物种的可塑性。在这项研究中，我们专注于蜥蜴属（和）和属（和）肝脏线粒体蛋白编码基因（PCGs）的转录水平在 8°C 低温条件下与 25°C 对照组相比的变化。同一蜥蜴属内的物种表现出不同的纬度分布模式。我们发现，两个 物种，和 ，采用代谢抑制策略（降低转录水平）来应对低温。相比之下，两个 物种表现出明显不同的模式：表现出显著增加了六个基因的转录水平（代谢补偿），而在 中，只有两个线粒体基因下调（代谢抑制）与对照组相比。我们还发现，生活在中高纬度的和 ，与生活在低纬度的和 相比，在线粒体基因水平上表现出更强的适应性和可塑性。我们认为这种增强的适应性与更多基因（可塑性基因）的更显著变化相对应。
