Not flying blind: a comparative study of photoreceptor function in flying and non-flying cockroaches
Not flying blind: a comparative study of photoreceptor function in flying and non-flying cockroaches
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DOI：
10.1242/jeb.159103
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发表时间：
2017-07-01
影响因子：
2.8
通讯作者：
Arikawa, Kentaro
中科院分区：
文献类型：
--
作者：
Frolov, Roman V.;Matsushita, Atsuko;Arikawa, Kentaro
飞行通常与上级视觉性能相关，因为良好的视觉对于检测和实施快速视觉引导的空中运动至关重要。因此，为了了解昆虫视觉系统的进化，比较在飞行能力上具有不同投资的昆虫遗传学相关物种是很重要的。在这里，我们描述和比较的形态和电生理特性的光感受器习惯性飞行的绿色蟑螂Panchlora nivea和美洲大蠊美洲大蠊，只飞在高环境温度。与大蠊属不同，全绿虫属的小眼具有两层横纹，这可能有助于在黑暗中飞行时检测偏振光。在膜片钳实验中，我们评估了对光的绝对灵敏度，基本和宏观光激活电流和电压响应，电压激活钾（Kv）电导和信息传递。这两个物种都是夜行性的，它们的光感受器对光线同样敏感。然而，一些重要的差异被发现，包括存在于Panchlora的一个突出的瞬态KV电流和感光性能的一般低的变异性。在Panchlora的最大信息率是三分之一高于大蠊，由于一个显着更高的增益和膜角频率。在性能上的差异不能完全解释的相异的光激活或KV电导，相反，我们建议的上级性能的Panchlora光感受器主要源于更好的同步的基本响应。这些研究结果提出了一个问题，是否感光性能的视觉需求进行不同的Blattodea比双翅目的进化调谐。
Flying is often associated with superior visual performance, as good vision is crucial for detection and implementation of rapid visually guided aerial movements. To understand the evolution of insect visual systems it is therefore important to compare phylogenetically related species with different investments in flight capability. Here, we describe and compare morphological and electrophysiological properties of photoreceptors from the habitually flying green cockroach Panchlora nivea and the American cockroach Periplaneta americana, which flies only at high ambient temperatures. In contrast to Periplaneta, ommatidia in Panchlora were characterized by two-tiered rhabdom, whichmight facilitate detection of polarized light while flying in the dark. In patch-clamp experiments, we assessed the absolute sensitivity to light, elementary and macroscopic light-activated current and voltage responses, voltage-activated potassium (Kv) conductances, and information transfer. Both species are nocturnal, and their photoreceptors were similarly sensitive to light. However, a number of important differences were found, including the presence in Panchlora of a prominent transient Kv current and a generally low variability in photoreceptor properties. The maximal information rate in Panchlora was one-third higher than in Periplaneta, owing to a substantially higher gain and membrane corner frequency. The differences in performance could not be completely explained by dissimilarities in the light-activated or Kv conductances; instead, we suggest that the superior performance of Panchlora photoreceptors mainly originates from better synchronization of elementary responses. These findings raise the issue of whether the evolutionary tuning of photoreceptor properties to visual demands proceeded differently in Blattodea than in Diptera.