Distinct neural and neuromuscular strategies underlie independent evolution of simplified advertisement calls.
Distinct neural and neuromuscular strategies underlie independent evolution of simplified advertisement calls.
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独特的神经和神经肌肉策略是简化广告呼叫独立进化的基础。
DOI：
10.1098/rspb.2012.2639
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发表时间：
2013
期刊：
影响因子：
--
通讯作者：
Kelley,DarcyB
中科院分区：
文献类型：
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作者：
Leininger,ElizabethC;Kelley,DarcyB
独立或趋同进化可以作为衍生行为特征的表型相似性的基础。确定潜在的神经和神经肌肉机制有助于阐明这些特征是如何产生的。进化衍生特征的一个例子是雄性非洲爪蟾（Xenopus）的一种时间上简单的广告叫声，它至少两次独立于一种更复杂的祖先模式。语音回路中的简化是如何发生的？为了区分共享的分歧机制，我们研究了两个物种的呼叫大脑和发声器官（喉）的活动，这些物种独立地进化出简化的呼叫。我们发现，每个物种使用不同的神经和神经肌肉策略，以产生简化的呼叫。孤立的非洲爪蟾的大脑产生虚构的声音模式，与实际男性呼叫的时间模式相匹配;喉部将神经活动忠实地转换为肌肉收缩和单次点击。相比之下，来自孤立的非洲爪蟾大脑的虚构模式是神经活动的短暂爆发;孤立的喉咙需要刺激爆发才能产生一声咔嗒声。所以，不喜欢X。borealis，X. boumbaensishindbrain发声模式发生器是一种古老的爆发型模式，由喉部转换为单次点击。因此，通过中枢和外周发声神经效应器的重新配置，在遗传上遥远的Xenopus物种中出现了时间上简单的广告呼叫。
Independent or convergent evolution can underlie phenotypic similarity of derived behavioural characters. Determining the underlying neural and neuromuscular mechanisms sheds light on how these characters arose. One example of evolutionarily derived characters is a temporally simple advertisement call of male African clawed frogs (Xenopus) that arose at least twice independently from a more complex ancestral pattern. How did simplification occur in the vocal circuit? To distinguish shared from divergent mechanisms, we examined activity from the calling brain and vocal organ (larynx) in two species that independently evolved simplified calls. We find that each species uses distinct neural and neuromuscular strategies to produce the simplified calls. IsolatedXenopus borealisbrains produce fictive vocal patterns that match temporal patterns of actual male calls; the larynx converts nerve activity faithfully into muscle contractions and single clicks. In contrast, fictive patterns from isolatedXenopus boumbaensisbrains are short bursts of nerve activity; the isolated larynx requires stimulus bursts to produce a single click of sound. Thus, unlikeX. borealis, the output of theX. boumbaensishindbrain vocal pattern generator is an ancestral burst-type pattern, transformed by the larynx into single clicks. Temporally simple advertisement calls in genetically distant species ofXenopushave thus arisen independently via reconfigurations of central and peripheral vocal neuroeffectors.