Feindt Wiebke, Oppenheim Sara J, DeSalle Robert, Goldstein Paul Z, Hadrys Heike
University of Veterinary Medicine Hannover, ITZ-Division of Ecology and Evolution, Hannover, Germany.
Leibniz University Hannover, Hannover, Germany.
PLoS One. 2018 Jan 12;13(1):e0189898. doi: 10.1371/journal.pone.0189898. eCollection 2018.
The evolution, development and coloration of insect wings remains a puzzling subject in evolutionary research. In basal flying insects such as Odonata, genomic research regarding bauplan evolution is still rare. Here we focus on the world's largest odonate species-the "forest giant" Megaloprepus caerulatus, to explore its potential for looking deeper into the development and evolution of wings. A recently discovered cryptic species complex in this genus previously considered monotypic is characterized by morphological differences in wing shape and color patterns. As a first step toward understanding wing pattern divergence and pathways involved in adaptation and speciation at the genomic level, we present a transcriptome profiling of M. caerulatus using RNA-Seq and compare these data with two other odonate species. The de novo transcriptome assembly consists of 61,560 high quality transcripts and is approximately 93% complete. For almost 75% of the identified transcripts a possible function could be assigned: 48,104 transcripts had a hit to an InterPro protein family or domain, and 28,653 were mapped to a Gene Ontology term. In particular, we focused on genes related to wing development and coloration. The comparison with two other species revealed larva-specific genes and a conserved 'core' set of over 8,000 genes forming orthologous clusters with Ischnura elegans and Ladona fulva. This transcriptome may provide a first point of reference for future research in odonates addressing questions surrounding the evolution of wing development, wing coloration and their role in speciation.
昆虫翅膀的进化、发育和着色在进化研究中仍然是一个令人困惑的课题。在诸如蜻蜓目等基础飞行昆虫中，关于体构进化的基因组研究仍然很少。在这里，我们聚焦于世界上最大的蜻蜓物种——“森林巨人”大蓝痣蟌，以探索其在深入研究翅膀发育和进化方面的潜力。在这个之前被认为是单型的属中，最近发现的一个隐存物种复合体具有翅膀形状和颜色模式的形态差异。作为在基因组水平上理解翅膀模式分歧以及参与适应和物种形成的途径的第一步，我们使用RNA测序技术对大蓝痣蟌进行了转录组分析，并将这些数据与另外两种蜻蜓物种进行了比较。从头转录组组装由61,560个高质量转录本组成，完整性约为93%。对于近75%已鉴定的转录本，可以确定其可能的功能：48,104个转录本与一个InterPro蛋白质家族或结构域匹配，28,653个转录本被映射到一个基因本体学术语。特别是，我们关注了与翅膀发育和着色相关的基因。与另外两个物种的比较揭示了幼虫特异性基因以及一组超过8000个保守的“核心”基因，它们与优雅蟌和黄纹蟌形成直系同源簇。这个转录组可能为未来蜻蜓研究提供首个参考点，这些研究将围绕翅膀发育进化、翅膀着色及其在物种形成中的作用等问题展开。
