Department of Biology, University of North Carolina Asheville, One University Heights, Asheville, NC 28804, USA.
Department of Biology, University of North Carolina Asheville, One University Heights, Asheville, NC 28804, USA; Department of Biology, Washington University in St. Louis, St. Louis, MO 63130, USA.
Mol Phylogenet Evol. 2022 Sep;174:107548. doi: 10.1016/j.ympev.2022.107548. Epub 2022 Jun 8.
The genus Cyclura includes nine extant species and six subspecies of West Indian Rock Iguanas and is one of the most imperiled genera of squamate reptiles globally. An understanding of species diversity, evolutionary relationships, diversification, and historical biogeography in this group is crucial for implementing sound long-term conservation strategies. We collected DNA samples from 1 to 10 individuals per taxon from all Cyclura taxa (n = 70 ingroup individuals), focusing where possible on incorporating individuals from different populations of each species. We also collected 1-2 individuals from each of seven outgroup species of iguanas (Iguana delicatissima; five Ctenosaura species) and Anolis sagrei (n = 12 total outgroup individuals). We used targeted genomic sequence capture to isolate and to sequence 1,872 loci comprising of 687,308 base pairs (bp) from each of the 82 individuals from across the nuclear genome. We extracted mitochondrial reads and assembled and annotated mitogenomes for all Cyclura taxa plus outgroup species. We present well-supported phylogenomic gene tree/species tree analyses for all extant species of Cyclura using ASTRAL-III, SVDQuartets, and StarBEAST2 methods, and discuss the taxonomic, biogeographic, and conservation implications of these data. We find a most recent common ancestor of the genus 9.91 million years ago. The earliest divergence within Cyclura separates C. pinguis from a clade comprising all other Cyclura. Within the latter group, a clade comprising C. carinata from the southern Lucayan Islands and C. ricordii from Hispaniola is the sister taxon to a clade comprising the other Cyclura. Among the other Cyclura, the species C. cornuta and C. stejnegeri (from Hispaniola and Isla Mona) form the sister taxon to a clade of species from Jamaica (C. collei), Cuba and Cayman Islands (C. nubila and C. lewisi), and the eastern (C. rileyi) and western (C. cychlura) Lucayan Islands. Cyclura cychlura and C. rileyi form a clade whose sister taxa are C. nubila and C. lewisi. Cyclura collei is the sister taxon to these four species combined.
该属包括 9 种现存的西印度岩鬣蜥物种和 6 个亚种，是全球最濒危的有鳞目爬行动物之一。了解该类群的物种多样性、进化关系、多样化和历史生物地理学对于实施健全的长期保护策略至关重要。我们从所有 Cyclura 分类群（n=70 个内群个体）中收集了 1-10 个个体的 DNA 样本，尽可能集中在每个物种的不同种群中纳入个体。我们还从七种鬣蜥外群物种（Iguana delicatissima；五种 Ctenosaura 物种）和 Anolis sagrei 中收集了 1-2 个个体（n=12 个外群个体）。我们使用靶向基因组序列捕获技术从核基因组中的 82 个个体中分离和测序了 1872 个包含 687308 个碱基对（bp）的位点。我们提取了线粒体读取序列，并组装和注释了所有 Cyclura 分类群加外群物种的线粒体基因组。我们使用 ASTRAL-III、SVDQuartets 和 StarBEAST2 方法为所有现存的 Cyclura 物种提供了支持良好的基因组系统发育树/物种树分析，并讨论了这些数据的分类学、生物地理学和保护意义。我们发现该属的最近共同祖先出现在 991 万年前。Cyclura 最早的分化将 C. pinguis 与一个包含所有其他 Cyclura 的分支分开。在后一组中，一个由南卢卡扬群岛的 C. carinata 和伊斯帕尼奥拉岛的 C. ricordii 组成的分支是另一个由其他 Cyclura 组成的分支的姐妹分类群。在其他 Cyclura 中，C. cornuta 和 C. stejnegeri（来自伊斯帕尼奥拉岛和莫纳岛）与来自牙买加（C. collei）、古巴和开曼群岛（C. nubila 和 C. lewisi）以及东部（C. rileyi）和西部（C. cychlura）卢卡扬群岛的物种形成姐妹分类群。Cyclura cychlura 和 C. rileyi 形成一个分支，其姐妹分类群是 C. nubila 和 C. lewisi。Cyclura collei 是这四个物种的姐妹分类群。
