Predation threats for a 24-h period activated the extension of axons in the brains of Xenopus tadpoles
Predation threats for a 24-h period activated the extension of axons in the brains of Xenopus tadpoles
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DOI：
10.1038/s41598-020-67975-7
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发表时间：
2020-07
影响因子：
4.6
通讯作者：
Tsukasa Mori;Yoichiro Kitani;Den Hatakeyama;Kazumasa Machida;Naoko Goto-Inoue;S. Hayakawa;N. Yamamoto;K. Kashiwagi;A. Kashiwagi
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文献类型：
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作者：
Tsukasa Mori;Yoichiro Kitani;Den Hatakeyama;Kazumasa Machida;Naoko Goto-Inoue;S. Hayakawa;N. Yamamoto;K. Kashiwagi;A. Kashiwagi
捕食的威胁是动物进化的驱动力。我们以前曾报道过，在日本蝾螈幼虫捕食者的存在下，非洲爪蟾增强了它们的尾部肌肉，增加了它们的游泳速度。本文利用3′-tag数字基因表达谱技术研究了捕食胁迫下蝌蚪脑内基因表达的变化。我们发现，许多肌肉基因表达后24小时暴露于捕食。免疫途径分析进一步表明，在24小时的捕食威胁后，各种信号转导基因被刺激，如影响肌动蛋白细胞骨架和CREB途径的基因，这些基因可能会增加微管动力学，轴突生成，认知和记忆。为了验证微管动力学的增加，通过蝌蚪鼻孔插入DiI。从中脑到间脑的轴突延伸清晰可见，与对照组相比，暴露于捕食24 h后，轴突的延伸显著增加（P≤ 0.0001）。如微管动力学所示，信号转导的动态变化似乎在神经网络中产生了新的连接。这些连接可能导致记忆和认知能力的改善，并随后增加生存能力。
The threat of predation is a driving force in the evolution of animals. We have previously reported thatXenopus laevisenhanced their tail muscles and increased their swimming speeds in the presence of Japanese larval salamander predators. Herein, we investigated the induced gene expression changes in the brains of tadpoles under the threat of predation using 3′-tag digital gene expression profiling. We found that many muscle genes were expressed after 24 h of exposure to predation. Ingenuity pathway analysis further showed that after 24 h of a predation threat, various signal transduction genes were stimulated, such as those affecting the actin cytoskeleton andCREBpathways, and that these might increase microtubule dynamics, axonogenesis, cognition, and memory. To verify the increase in microtubule dynamics, DiI was inserted through the tadpole nostrils. Extension of the axons was clearly observed from the nostril to the diencephalon and was significantly increased (P≤ 0.0001) after 24 h of exposure to predation, compared with that of the control. The dynamic changes in the signal transductions appeared to bring about new connections in the neural networks, as suggested by the microtubule dynamics. These connections may result in improved memory and cognition abilities, and subsequently increase survivability.