Recent large-scale studies of opsin gene contents in representatives of the largest order of insects, the Coleoptera (beetles), revealed that the blue wavelength-sensitive (B) opsin subfamily is absent in this clade, while the ultraviolet- (UV) and long wavelength-sensitive (LW) opsin subfamilies are broadly conserved with gene duplications possibly reintroducing blue sensitivity in select subclades. Little is known yet, however, how opsin genes are expressed in the compound eyes of beetles. In a previous study, we analyzed opsin gene expression in the red flour beetle Tribolium castaneum, a member of the family of darkling beetles (Tenebrionidae), and found that a singleton LW opsin homolog is homogeneously expressed in all photoreceptors of the compound eye retina with a singleton UV opsin homolog being co-expressed in the R7 subtype photoreceptors. To probe for the evolutionary conservation of these expression patterns, we isolated complete opsin transcript sequences from three additional species in the subfamily Tenebrionidae (Tribolium confusum, Tenebrio molitor, Zophobas morio) and studied their expression via whole mount in situ hybridization in the pupal retina. These experiments revealed very similar, if not identical, photoreceptor subtype-specific expression patterns in all three species compared with T. castaneum. Documenting a deep conservation of photoreceptor subtype-specific opsin gene expression in this range of darkling beetles, our study provides a first point of reference for broader comparative studies of retinal organization in the Coleoptera.

最近对最大的昆虫（鞘翅目）代表中的视蛋白基因含量的大规模研究表明，该进化枝中不存在对波长敏感的蓝色（B）视蛋白亚科，而紫外线（UV）和长波长敏感（LW）视蛋白亚家族在基因重复方面得到了广泛的保护，可能会在选择的子领域中重新引入蓝色敏感性。然而，关于视蛋白基因如何在甲虫的复眼中表达还知之甚少。在先前的研究中，我们分析了红色面粉甲虫Tribolium castaneum中的视蛋白基因表达，是黑夜虫科（Tenebrionidae）的成员，发现单眼LW视蛋白同系物在复合眼视网膜的所有光感受器中均质表达，而单眼UV视蛋白同系物在R7亚型光感受器中共表达。为了探究这些表达模式的进化保守性，我们从天蛾科亚科（Tribolium confusum，黄粉虫，黄粉虫（Zophobas morio））的三个其他物种中分离了完整的视蛋白转录序列，并通过在mount视网膜中的完整原位杂交研究了它们的表达。这些实验表明，与锥栗木compared相比，所有三个物种的感光体亚型特异性表达模式都非常相似，甚至不完全相同。。记录了在这一范围的黑甲虫中光受体亚型特异性视蛋白基因表达的深入保守，我们的研究为鞘翅目视网膜组织的更广泛的比较研究提供了第一参考点。