A Complex Lens for a Complex Eye.
A Complex Lens for a Complex Eye.
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适合复杂眼睛的复杂镜片。
DOI：
10.1093/icb/icx116
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发表时间：
2017
影响因子：
2.6
通讯作者：
Buschbeck,ElkeK
中科院分区：
文献类型：
--
作者：
Stahl,AaronL;Baucom,ReginaS;Cook,TiffanyA;Buschbeck,ElkeK
高分辨率眼睛的一个关键创新是一个精密的透镜，它可以精确地将光线聚焦到感光器上。全变态幼虫的眼睛范围从仅仅检测光的非常简单的眼睛到能够高空间分辨率的眼睛。特别有趣的是Thermonectus marmoratus幼虫的双焦点透镜，它可以将光线聚焦在光谱不同的视网膜上。虽然昆虫晶状体的功能方面已经得到了比较好的研究，但很少有工作探索它们的分子组成，特别是在更复杂的眼睛类型方面。为了研究这个问题，我们采用了转录组学和蛋白质组学的方法来鉴定T. marmoratuslarvae.质谱分析揭示了10种主要的透镜蛋白。其中6个与表皮蛋白具有序列同源性，表皮蛋白是一大类蛋白质，也是果蝇和冈比亚按蚊成年复眼角膜晶状体的主要成分。两个蛋白质被鉴定为管家基因，最后两个与已知基因缺乏任何序列同源性。总的来说，该组合物似乎遵循一种吸收透明和光学致密蛋白质的模式，类似于对其他动物晶状体的描述。为了鉴定负责分泌特异性透镜蛋白的细胞，我们进行了原位杂交研究，发现远侧和近侧角膜细胞之间存在一些表达差异。由于远端细胞可能产生周边和近端细胞的透镜的中心，我们的研究结果强调了一个可能的机制，建立结构差异，符合这些镜头的双焦点性质。对透镜组成的更好理解提供了对适当聚焦的演变的见解，这是低分辨率和高分辨率眼睛之间过渡的重要一步。
A key innovation for high resolution eyes is a sophisticated lens that precisely focuses light onto photoreceptors. The eyes of holometabolous larvae range from very simple eyes that merely detect light to eyes that are capable of high spatial resolution. Particularly interesting are the bifocal lenses ofThermonectus marmoratuslarvae, which differentially focus light on spectrally-distinct retinas. While functional aspects of insect lenses have been relatively well studied, little work has explored their molecular makeup, especially in regard to more complex eye types. To investigate this question, we took a transcriptomic and proteomic approach to identify the major proteins contributing to the principal bifocal lenses ofT. marmoratuslarvae. Mass spectrometry revealed 10 major lens proteins. Six of these share sequence homology with cuticular proteins, a large class of proteins that are also major components of corneal lenses from adult compound eyes ofDrosophila melanogasterandAnopheles gambiae. Two proteins were identified as house-keeping genes and the final two lack any sequence homologies to known genes. Overall the composition seems to follow a pattern of co-opting transparent and optically dense proteins, similar to what has been described for other animal lenses. To identify cells responsible for the secretion of specific lens proteins, we performedin situhybridization studies and found some expression differences between distal and proximal corneagenous cells. Since the distal cells likely give rise to the periphery and the proximal cells to the center of the lens, our findings highlight a possible mechanism for establishing structural differences that are in line with the bifocal nature of these lenses. A better understanding of lens composition provides insights into the evolution of proper focusing, which is an important step in the transition between low-resolution and high-resolution eyes.