Eyes with basic dorsal and specific ventral regions in the glacial Apollo, Parnassius glacialis (Papilionidae)
Eyes with basic dorsal and specific ventral regions in the glacial Apollo, Parnassius glacialis (Papilionidae)
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DOI：
10.1242/jeb.048678
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发表时间：
2010-12-01
影响因子：
2.8
通讯作者：
Arikawa, Kentaro
中科院分区：
文献类型：
--
作者：
Awata, Hiroko;Matsushita, Atsuko;Arikawa, Kentaro
最近对蝴蝶的研究表明，它们的颜色视觉系统几乎是物种特异性的。为了解决这个惊人的多样性是如何进化的问题，我们研究了冰川阿波罗的眼睛，Parnassius glacialis，一种属于凤蝶科的活化石物种。我们在Parnassius的眼睛中鉴定了四种视蛋白-一种紫外线（PgUV），一种蓝色（PgB）和两种长波（PgL2, PgL3）吸收类型-并将它们的mrna定位在视网膜内。因此，我们发现了眼的基质异质性和明显的背-腹区。背部区域由三种基本类型的小眼组成，与其他昆虫相似，表明该背部区域保留了祖先的状态。在腹侧区域，我们发现了两种新的现象：紫外线和b吸收型视蛋白在一个光感受器亚群中共同表达，以及由于PgL2和PgL3 mrna的差异表达而导致远端层长波受体的亚功能化。有趣的是，来自近亲凤蝶属的蝴蝶（凤蝶科）至少有三种长波视蛋白，L1-L3。本研究表明，L2和L3的重复发生在凤蝶谱系分化之前，而L1在凤蝶谱系中是由L3产生的。
Recent studies on butterflies have indicated that their colour vision system is almost species specific. To address the question of how this remarkable diversity evolved, we investigated the eyes of the glacial Apollo, Parnassius glacialis, a living fossil species belonging to the family Papilionidae. We identified four opsins in the Parnassius eyes - an ultraviolet-(PgUV), a blue-(PgB), and two long wavelength (PgL2, PgL3)-absorbing types - and localized their mRNAs within the retina. We thus found ommatidial heterogeneity and a clear dorso-ventral regionalization of the eye. The dorsal region consists of three basic types of ommatidia that are similar to those found in other insects, indicating that this dorsal region retains the ancestral state. In the ventral region, we identified two novel phenomena: co-expression of the opsins of the UV- and B-absorbing type in a subset of photoreceptors, and subfunctionalization of long-wavelength receptors in the distal tier as a result of differential expression of the PgL2 and PgL3 mRNAs. Interestingly, butterflies from the closely related genus Papilio (Papilionidae) have at least three long-wavelength opsins, L1-L3. The present study indicates that the duplication of L2 and L3 occurred before the Papilio lineage diverged from the rest, whereas L1 was produced from L3 in the Papilio lineage.