Dichromatic vision in a fruit bat with diurnal proclivities: the Samoan flying fox (Pteropus samoensis)
Dichromatic vision in a fruit bat with diurnal proclivities: the Samoan flying fox (Pteropus samoensis)
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DOI：
10.1007/s00359-014-0951-x
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发表时间：
2014-12-01
影响因子：
2.1
通讯作者：
Dominy, Nathaniel J.
中科院分区：
文献类型：
--
作者：
Melin, Amanda D.;Danosi, Christina F.;Dominy, Nathaniel J.
在哺乳动物进化过程中的一个夜间瓶颈使大多数物种具有两种锥视蛋白，或双色色觉。灵长类三色视觉起源于X连锁视蛋白基因的复制和分化，长期以来被认为是由食虫性到食果性的串联转变。在翼手目中存在视蛋白基因变异和至少一个复制事件，表明三色视觉可以在有利的生态条件下进化。萨摩亚狐蝠（Pteropus samoensis）的自然历史符合这些条件，它是一种大型蝙蝠，消耗花蜜和水果，并表现出强烈的日间倾向。它还拥有与灵长类动物惊人相似的视觉系统。为了探索视蛋白基因重复和分歧的可能性，我们对来自南太平洋三个岛屿的11个个体（19条X染色体）的视蛋白基因进行了测序。我们的研究结果表明，均匀存在的两个视蛋白与预测的峰值灵敏度约。360和553 nm。这一结果未能支持昼夜食果动物和三色视觉之间的因果关系，尽管萨摩亚对虾的昼夜活动没有足够的古老性来支持视蛋白基因的更新仍然是合理的。
A nocturnal bottleneck during mammalian evolution left a majority of species with two cone opsins, or dichromatic color vision. Primate trichromatic vision arose from the duplication and divergence of an X-linked opsin gene, and is long attributed to tandem shifts from nocturnality to diurnality and from insectivory to frugivory. Opsin gene variation and at least one duplication event exist in the order Chiroptera, suggesting that trichromatic vision could evolve under favorable ecological conditions. The natural history of the Samoan flying fox (Pteropus samoensis) meets these conditions-it is a large bat that consumes nectar and fruit and demonstrates strong diurnal proclivities. It also possesses a visual system that is strikingly similar to that of primates. To explore the potential for opsin gene duplication and divergence in this species, we sequenced the opsin genes of 11 individuals (19 X-chromosomes) from three South Pacific islands. Our results indicate the uniform presence of two opsins with predicted peak sensitivities of ca. 360 and 553 nm. This result fails to support a causal link between diurnal frugivory and trichromatic vision, although it remains plausible that the diurnal activities of P. samoensis have insufficient antiquity to favor opsin gene renovation.