Forgotten treasures – using historic collections to assess the diversity and systematics of wide-ranging taxa: A case study using African Hinge-back Tortoises (Kinixys spp.)

被遗忘的宝藏 â 使用历史收藏来评估广泛分类单元的多样性和系统性：使用非洲铰背龟（Kinixys spp.）的案例研究

• 批准号: 427271746
• 负责人: Dr. Flora Ihlow
• 金额: --
• 依托单位: Museum für Tierkunde
• 依托单位国家: 德国
• 项目类别: Research Grants
• 财政年份: 2019
• 资助国家: 德国
• 起止时间: 2018-12-31 至 2022-12-31
• 项目状态: 已结题
• 来源: https://gepris.dfg.de/gepris/projekt/427271746?language=en
• 关键词: Forgotten; treasures; using; historic; collections

The implementation of molecular genetic approaches into taxonomy accelerated exponentially the discovery of unrecognized taxa and many putatively widely distributed species were identified as species complexes. This implies that putatively widespread and common species may harbor multiple narrowly distributed and endangered taxa. Consequently, putatively widespread taxa need considerably more attention. However, obtaining range-wide sampling for taxa with ranges dissecting several political borders is expensive, time consuming, and hampered by legislative restrictions. Therefore, genetic samples obtained from scientific collections represent an appealing alternative. Unfortunately, DNA of museum specimens is often heavily degraded, fragmented, and contaminated with exogenous DNA. Thus, processing requires extensive precautions, special facilities, and approaches. The advent of Next Generation Sequencing (NGS) and hybridization-based target enrichment have revolutionized genetic research and improved the possibilities for using historic material significantly. The proposed project will apply NGS and aDNA approaches to elucidate exemplarily the diversity of three wide-ranging tortoise species using historic collection material, a set of mitochondrial and nuclear markers, and a stepwise analyses protocol. For the selected species only a few fresh samples are available from restricted range portions but large numbers of historic specimens are housed in scientific collections. All three species occupy wide distribution ranges spanning across up to 13 countries in sub-Saharan Africa. My preliminary genetic analyses revealed high misidentification rates for these morphologically challenging species and thus render the current taxonomic identification of name-bearing type specimens questionable. In addition, the currently accepted distribution ranges are evidently highly speculative as demonstrated by genetic analyses as well as species distribution models. In the frame of this project range-wide genetic variation and the taxonomic identity of the name-bearing type specimens and all respective synonyms of the African Hinge-back Tortoises Kinixys belliana, K. spekii and K. zombensis will genetically be re-examined. Taxonomy will be revised where necessary. By assigning dubious specimens to the correct species, distribution ranges will be corrected and updated. The project aims to develop a simple, fast, and cost-efficient workflow that facilitates quantitative assessments of genetic diversity for wide-ranging taxa using a limited number of historic samples. Taxonomically relevant levels of genetic divergence between congeners will be used to calibrate a ‘multi-locus yardstick’ to place observed divergences within the target group into a meaningful context. This will facilitate the reliable identification of cryptic or overlooked taxa. The resulting protocol can be applied to any wide-ranging vertebrate taxon.

分子遗传学方法在分类学中的应用加速了未被识别的分类群的发现，许多广泛分布的物种被确定为物种复合体。这意味着，广布和常见的物种可能窝藏多个狭窄的分布和濒危类群。因此，普适分布的类群需要更多的关注。然而，获得范围广泛的采样与范围解剖几个政治边界的类群是昂贵的，耗时的，并受到立法限制。因此，从科学收藏品中获得的遗传样本是一种有吸引力的选择。不幸的是，博物馆标本的DNA通常严重降解，碎片化，并被外源DNA污染。因此，处理需要广泛的预防措施，特殊设施和方法。下一代测序（NGS）和基于杂交的目标富集的出现彻底改变了遗传研究，并显着提高了使用历史材料的可能性。拟议的项目将采用NGS和aDNA方法，利用历史收集材料，一套线粒体和核标记，以及逐步分析方案，举例说明三种广泛分布的龟类物种的多样性。对于选定的物种，只有少数新鲜样品可从有限的范围部分，但大量的历史标本被安置在科学收藏。所有这三个物种都分布在撒哈拉以南非洲的13个国家。我的初步遗传分析显示，这些形态上具有挑战性的物种的错误识别率很高，因此使目前的分类鉴定的命名模式标本值得怀疑。此外，遗传分析和物种分布模型表明，目前公认的分布范围显然是高度推测性的。在本项目的框架内，对非洲铰背龟Kinixys belliana、K. spekii和K.松本虫的基因将被重新检验必要时将修订分类法。通过将可疑的标本分配给正确的物种，分布范围将得到纠正和更新。该项目旨在开发一个简单、快速和具有成本效益的工作流程，便于使用有限数量的历史样本对广泛的分类群进行遗传多样性的定量评估。同源物之间遗传差异的分类学相关水平将用于校准“多位点尺度”，以便将目标群体内观察到的差异置于有意义的背景下。这将有助于可靠地识别神秘或被忽视的类群。由此产生的协议可以适用于任何广泛的脊椎动物分类。