Abstract:
A fine-scale phylogenetic and phylogeographic analysis of Peripatopsis lawrencei s.l. was conducted with both mitochondrial and nuclear DNA sequence data, using both external morphology and scanning electron microscopy of taxonomically important characters. A total of 119 sequences were used for the mitochondrial cytochrome c oxidase subunit I (COI ) whereas a single representative specimen from each locality was sequenced for the nuclear 18S rRNA locus. Phylogenetic analyses were conducted on the total COI data set and the combined COI + 18S rRNA data set using a Bayesian analysis and maximum likelihood analyses. For the combined DNA sequence data set, a divergence time estimation was further undertaken in BEAST and specimens placed in a phylogenetic framework including all the described Peripatopsis species from South Africa. In addition, a phylogeographic study was conducted exclusively on P. lawrencei s.s. (clade A) using an analysis of molecular variance and haplotype network. Phylogenetic results indicated that, at the Oubos sample locality, two highly distinct genetic lineages were present (clades A and B), whereas a divergence time estimation suggests a Miocene cladogenesis of the novel Oubos lineage. Marked phylogeographic structure was observed for P. lawrencei s.s. (restricted to clade A) across the distribution range with limited maternal dispersal. Morphologically, the two sympatric lineages at Oubos A and B differed in leg pair number, ventral colour and dorsal scale rank counts, as evident from scanning electron microscopy. Our results support the recognition of a distinct species that occurs in sympatry with P. lawrencei s.s. The new species, P. aereus sp. nov. (clade B) is described and the implication for fine-scale taxonomic studies on saproxylic taxa is discussed. ZooBank: urn:lsid:zoobank.org:pub:AB6E0BDA-7B5F-4FD3-A863-BA7C814E278C.
摘要:
利用线粒体和核DNA序列数据对罗氏根瘤菌进行了精细的系统发育和系统地理学分析,使用外部形态和扫描电子显微镜对分类学上重要的特征。共有119个序列用于线粒体细胞色素c氧化酶亚基I(COI),而每个位置的单个代表性样本则针对核18SrRNA基因座进行了测序。使用贝叶斯分析和最大似然分析对总COI数据集和组合的COI+18SrRNA数据集进行系统发育分析。对于合并的DNA序列数据集,在BEAST中进一步进行了差异时间估计,并将标本置于系统发育框架中,包括来自南非的所有所述Peripatus物种。此外,仅对P.lawrenceis.s.(进化枝A)进行了系统地理学研究,使用分子方差分析和单倍型网络。系统发育结果表明,在Oubos样本地点,存在两个高度不同的遗传谱系(进化枝A和B),而分歧的时间估计表明,新的Oubos谱系的Miocene形成。观察到P.lawrenceis.s.(仅限于进化枝A)在整个分布范围内具有有限的母体散布。形态学上,OubosA和B的两个同胞血统在腿对数上不同,腹侧颜色和背侧尺度等级计数,从扫描电子显微镜可以明显看出。我们的结果支持对与P.lawrenceis.s.共生的不同物种的认识。新物种,P.aereussp.11月。描述了(进化枝B),并讨论了对腐植酸类群进行精细分类研究的意义。ZooBank:urn:lsid:zoobank.org:pub:AB6E0BDA-7B5F-4FD3-A863-BA7C814E278C。