Smithsonian Institution, National Museum of Natural History, 10(th) and Constitution Ave. NW, Washington, D.C. 20560-0105, U.S.A..
Smithsonian Institution, National Museum of Natural History, 10(th) and Constitution Ave. NW, Washington, D.C. 20560-0105, U.S.A.
Mol Phylogenet Evol. 2018 Oct;127:907-918. doi: 10.1016/j.ympev.2018.06.038. Epub 2018 Jun 30.
Historical museum specimens are invaluable for morphological and taxonomic research, but typically the DNA is degraded making traditional sequencing techniques difficult to impossible for many specimens. Recent advances in Next-Generation Sequencing, specifically target capture, makes use of short fragment sizes typical of degraded DNA, opening up the possibilities for gathering genomic data from museum specimens. This study uses museum specimens and recent target capture sequencing techniques to sequence both Ultra-Conserved Elements (UCE) and exonic regions for lineages that span the modern spiders, Araneomorphae, with a focus on Palpimanoidea. While many previous studies have used target capture techniques on dried museum specimens (for example, skins, pinned insects), this study includes specimens that were collected over the last two decades and stored in 70% ethanol at room temperature. Our findings support the utility of target capture methods for examining deep relationships within Araneomorphae: sequences from both UCE and exonic loci were important for resolving relationships; a monophyletic Palpimanoidea was recovered in many analyses and there was strong support for family and generic-level palpimanoid relationships. Ancestral character state reconstructions reveal that the highly modified carapace observed in mecysmaucheniids and archaeids has evolved independently.
历史博物馆标本对于形态学和分类学研究具有不可估量的价值,但通常情况下,这些标本的 DNA 已经降解,使得传统的测序技术难以或不可能应用于许多标本。最近在下一代测序技术方面的进展,特别是目标捕获技术,利用了典型降解 DNA 的短片段大小,为从博物馆标本中收集基因组数据开辟了可能性。本研究使用博物馆标本和最近的目标捕获测序技术,对跨越现代蜘蛛目(Araneomorphae)的谱系进行超保守元件(UCE)和外显子区域的测序,重点是 Palpimanoidea 目。虽然许多先前的研究已经在干燥的博物馆标本(例如,皮肤、针插昆虫)上使用了目标捕获技术,但本研究包括了过去二十年来收集并在室温下保存在 70%乙醇中的标本。我们的研究结果支持目标捕获方法在研究 Araneomorphae 内部的深层关系方面的有效性:来自 UCE 和外显子区域的序列对于解决关系至关重要;在许多分析中都恢复了单系的 Palpimanoidea 目,并且对科和属级别的 palpimanoid 关系有很强的支持。祖先特征状态重建揭示了在 mecysmaucheniids 和 archaeids 中观察到的高度修饰的甲壳已经独立进化。