成都生物所在PLOS ONE报道视觉在夜行蛾子的正常生活中依然很重

视觉是动物最重要的通讯手段之一，其进化历程一直以来都为学者所关注。蝴蝶和蛾子是鳞翅目昆虫的两大支系，其活动规律存在显著差异，蝴蝶白天活动，而蛾子则主要是夜间活动。有研究表明视觉对蝴蝶的行为活动有非常重要的作用，而夜行性蛾子的行为活动依赖视觉的程度还是一个尚待解决的问题。

中国科学院成都生物研究所系统进化与保育学科组吕彬博士与中国农科院北京植保所昆虫生物学重点实验室合作，研究蛾子的视觉基因是否由于夜行性而发生了改变。研究人员从12个蛾类物种中分别克隆了红光、蓝光和紫外3类视觉基因，在这3类基因中都发现了较强的净化选择作用，说明基因功能的改变受到了限制。

基因定量表达研究发现，经过光暗条件处理后，视觉基因的表达发生了快速明显的改变，说明光线强弱能在很大程度上影响视觉基因的表达模式。这些结果都暗示了视觉在蛾子的正常生活中依然扮演着重要的作用，而非之前所预想的那样发生了退化或功能丧失。

研究成果发表于PLOS ONE上。

原文摘要：

The Evolution and Expression of the Moth Visual Opsin Family

Pengjun Xu, Bin Lu, Haijun Xiao, Xiaowei Fu, Robert W. Murphy, Kongming Wu

Because visual genes likely evolved in response to their ambient photic environment, the dichotomy between closely related nocturnal moths and diurnal butterflies forms an ideal basis for investigating their evolution. To investigate whether the visual genes of moths are associated with nocturnal dim-light environments or not, we cloned long-wavelength (R), blue (B) and ultraviolet (UV) opsin genes from 12 species of wild-captured moths and examined their evolutionary functions. Strong purifying selection appeared to constrain the functions of the genes. Dark-treatment altered the levels of mRNA expression in Helicoverpa armigera such that R and UV opsins were up-regulated after dark-treatment, the latter faster than the former. In contrast, B opsins were not significantly up-regulated. Diel changes of opsin mRNA levels in both wild-captured and lab-reared individuals showed no significant fluctuation within the same group. However, the former group had significantly elevated levels of expression compared with the latter. Consequently, environmental conditions appeared to affect the patterns of expression. These findings and the proportional expression of opsins suggested that moths potentially possessed color vision and the visual system played a more important role in the ecology of moths than previously appreciated. This aspect did not differ much from that of diurnal butterflies.

标签: 视觉 夜行蛾子 基因定量表达

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