Sensory evolution in blind cavefish is driven by early embryonic events during gastrulation and neurulation
Sensory evolution in blind cavefish is driven by early embryonic events during gastrulation and neurulation
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DOI：
10.1242/dev.141291
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发表时间：
2016-12-01
期刊：
影响因子：
4.6
通讯作者：
Retaux, Sylvie
中科院分区：
文献类型：
--
作者：
Hinaux, Helene;Devos, Lucie;Retaux, Sylvie
感觉系统的自然变化构成了对环境的适应性反应。在这里，我们比较了盲目洞穴适应变种和有眼河流栖息变型的感觉胎盘发育。聚焦于晶状体和嗅觉安慰剂，我们发现了这两种感觉成分之间的权衡：从神经板阶段开始，穴鱼有较大的嗅觉安慰剂和较小的晶状体安慰剂。为了探索洞鱼感觉进化的发育机制，我们分析了Shh、Fgf8和Bmp4信号的作用，这些信号是脊椎动物头部模式形成的基础，在洞穴鱼胚胎发生过程中在空间和时间上受到微妙的调节。在原肠作用结束时对这些信号系统进行调制，使平衡转向更大的嗅觉导数。用来评估这种发育进化的潜在行为结果的嗅觉测试表明，海鞘鱼能够对比它们的表层栖息同类低10(5)倍的氨基酸浓度做出反应。我们认为，类似的进化发育机制可能在整个脊椎动物中使用，以根据生活方式和栖息地来驱动适应性感觉专门化。
Natural variations in sensory systems constitute adaptive responses to the environment. Here, we compared sensory placode development in the blind cave-adapted morph and the eyed river-dwelling morph of Astyanax mexicanus. Focusing on the lens and olfactory placodes, we found a trade-off between these two sensory components in the two morphs: from neural plate stage onwards, cavefish have larger olfactory placodes and smaller lens placodes. In a search for developmental mechanisms underlying cavefish sensory evolution, we analyzed the roles of Shh, Fgf8 and Bmp4 signaling, which are known to be fundamental in patterning the vertebrate head and are subtly modulated in space and time during cavefish embryogenesis. Modulating these signaling systems at the end of gastrulation shifted the balance toward a larger olfactory derivative. Olfactory tests to assess potential behavioral outcomes of such developmental evolution revealed that Astyanax cavefish are able to respond to a 10(5)-fold lower concentration of amino acids than their surface-dwelling counterparts. We suggest that similar evolutionary developmental mechanisms may be used throughout vertebrates to drive adaptive sensory specializations according to lifestyle and habitat.