How thermal challenges change gene regulation in the songbird brain and gonad: Implications for sexual selection in our changing world
How thermal challenges change gene regulation in the songbird brain and gonad: Implications for sexual selection in our changing world
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DOI：
10.1111/mec.16506
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发表时间：
2022-05-31
影响因子：
4.9
通讯作者：
Derryberry，Elizabeth P.
中科院分区：
文献类型：
--
作者：
Lipshutz，Sara E.;Howell，Clara R.;Derryberry，Elizabeth P.
在一个迅速变暖的世界里，暴露在高温下可能会影响健康，但将亚致死温度与性选择性状联系起来的基因调控机制还没有得到很好的理解，特别是在吸热动物中。我们的实验使用了斑胸草雀（Taeniopygia guttata），这是一种在澳大利亚本土经历极端温度波动的鸣禽。我们将捕获的雄性暴露于急性热挑战（43°C），与热中性（35°C）和更低的温度（27°C）进行比较。我们发现，在43°C时，散热行为明显增加，而在27°C时，这种温度会减少歌曲的产生和生育能力，并有更多的保温行为。接下来，我们的特点是转录组反应的组织重要的交配努力后端脑，其作用在歌曲的生产，和睾丸，其作用在生育和激素的生产。睾丸中数百个基因的差异表达，但大脑中的基因很少，这表明大脑对极端温度的反应较低。然而，基因网络分析显示，大脑中与多巴胺能信号传导相关的表达与散热行为共变，提供了一种机制，通过这种机制，暂时的热挑战可能会改变歌曲产生的动机回路。在大脑和睾丸中，我们观察到热敏基因网络与体温调节行为的个体差异之间的相关性。虽然我们不能直接将这些基因调控变化与交配成功联系起来，但我们的研究结果表明，在一个变暖的世界里，个体对热挑战的反应可能会影响性选择特征。
In a rapidly warming world, exposure to high temperatures may impact fitness, but the gene regulatory mechanisms that link sublethal heat to sexually selected traits are not well understood, particularly in endothermic animals. Our experiment used zebra finches (Taeniopygia guttata), songbirds that experience extreme temperature fluctuations in their native Australia. We exposed captive males to an acute thermal challenge (43°C) compared with thermoneutral (35°C) and lower (27°C) temperatures. We found significantly more heat dissipation behaviours at 43°C, a temperature previously shown to reduce song production and fertility, and more heat retention behaviours at 27°C. Next, we characterized transcriptomic responses in tissues important for mating effort—the posterior telencephalon, for its role in song production, and the testis, for its role in fertility and hormone production. Differential expression of hundreds of genes in the testes, but few in the brain, suggests the brain is less responsive to extreme temperatures. Nevertheless, gene network analyses revealed that expression related to dopaminergic signalling in the brain covaried with heat dissipation behaviours, providing a mechanism by which temporary thermal challenges may alter motivational circuits for song production. In both brain and testis, we observed correlations between thermally sensitive gene networks and individual differences in thermoregulatory behaviour. Although we cannot directly relate these gene regulatory changes to mating success, our results suggest that individual variation in response to thermal challenges could impact sexually selected traits in a warming world.