Data from: Comparisons of behavioral and TRPA1 heat sensitivities in three sympatric Cuban Anolis lizards

Thermal tolerances of organisms play a role in defining geographic ranges and occurrence of species. In Cuba, three sympatric species of Anolis lizards (Anolis allogus, Anolis homolechis, and Anolis sagrei) inhabit different thermal microhabitats. A previous study found that these species showed distinct gene expression patterns in response to temperature stimuli, suggesting the genetically distinct thermal physiology among species. To investigate whether the Anolis species inhabiting locally distinct thermal habitats diverge their thermal tolerances, we first conducted behavioral experiments to analyze the temperatures at which the three Anolis species escape from heat source. Then, for each of the three species, we isolated cDNA encoding a putative molecular heat sensor, transient receptor potential ion channel ankyrin 1 (TRPA1), which has been suggested to play a role on eliciting behavioral responses to heat stimuli. We performed electrophysiological analysis to quantify activation temperature of Anolis TRPA1 to see whether the pattern of divergence in TRPA1 responses is congruent with that of divergence in behavioral responses. We found that temperatures triggering behavioral and TRPA1 responses were significantly lower for shade-dwelling species (A. allogus) than for sun-dwelling species (A. homolechis and A. sagrei). The ambient temperature of shade habitats where A. allogus occurs stays relatively cool compared to that of open habitats where A. homolechis and A. sagrei occur and bask. The high temperature thresholds of A. homolechis and A. sagrei may reflect their heat tolerances that would benefit these species to inhabit the open habitats.

生物热耐受性是决定物种地理分布范围与发生格局的关键因素之一。在古巴，有三种同域分布的安乐蜥属（Anolis）蜥蜴：全趾安乐蜥（Anolis allogus）、同质安乐蜥（Anolis homolechis）与萨氏安乐蜥（Anolis sagrei），它们分别栖息于不同的热微生境中。既往研究表明，这三种安乐蜥对温度刺激的基因表达模式存在显著差异，提示不同物种间的热生理特性存在遗传分化。为探究栖息于局部热环境存在差异的安乐蜥物种是否会发生热耐受性分化，我们首先开展行为学实验，测定三种安乐蜥逃离热源的临界温度。随后，我们分别从三个物种中克隆得到编码推定分子热传感器的cDNA：瞬时受体电位离子通道锚蛋白1（transient receptor potential ion channel ankyrin 1, TRPA1），该通道被认为在介导热刺激引发的行为反应中发挥作用。我们通过电生理学实验定量测定安乐蜥TRPA1的激活温度，以验证TRPA1响应的分化模式是否与行为响应的分化模式相一致。研究结果显示，栖息于阴凉生境的全趾安乐蜥（A. allogus）触发行为与TRPA1响应的温度，显著低于栖息于向阳生境的同质安乐蜥（A. homolechis）与萨氏安乐蜥（A. sagrei）。全趾安乐蜥栖息的阴凉生境环境温度，显著低于同质安乐蜥与萨氏安乐蜥栖息并进行晒背的开阔生境。同质安乐蜥与萨氏安乐蜥较高的温度阈值，可能反映了它们的热耐受能力，这使其能够适应开阔生境。