Malukiewicz Joanna, Hepp Crystal M, Guschanski Katerina, Stone Anne C
School of Life Sciences, Arizona State University, Tempe, Arizona, 85287, USA.
School of Informatics, Computing, and Cyber Systems, Northern Arizona University, Flagstaff, AZ 86011, USA.
Am J Phys Anthropol. 2017 Jan;162(1):157-169. doi: 10.1002/ajpa.23105. Epub 2016 Oct 20.
Two subgroups make up the marmoset genus Callithrix. The "aurita" group is composed of two species, whereas evolutionary relationships among the four species of the "jacchus" group remain unclear. To uncover these relationships, we first sequenced mitochondrial genomes for C. kuhlii and C. penicillata to complement data available for congeners. We then constructed a phylogenetic tree based on mtDNA heavy chain protein coding genes from several primates to untangle species relationships and estimate divergence times of the jacchus group.
MtDNA genomes of C. kuhlii and C. penicillata were Sanger sequenced. These Callithrix mitogenomes were combined with other publically available primate mtDNA genomes. Phylogenies were produced using maximum likelihood and Bayesian inference. Finally, divergence times within the jacchus group of marmosets were estimated with Bayesian inference.
In our phylogenetic tree, C. geoffroyi was the sister to all other jacchus group species, followed by C. kuhlii, while C. jacchus and C. penicillata diverged most recently. Bayesian inference showed that C. jacchus and C. penicillata diverged approximately 0.70 MYA and that the jacchus group radiated approximately 1.30 MYA.
Callithrix nuclear and mtDNA phylogenies frequently result in polytomies and paraphyly. Here, we present a well-supported phylogenetic tree based on mitochondrial genome sequences, which facilitates the understanding of the divergence of the jacchus marmosets. Our results demonstrate how mitochondrial genomes can enrich Callithrix phylogenetic studies by alleviating some of the difficulties faced by previous mtDNA studies and allow formulation of hypotheses to test further under larger genomic-scale analyses.
狨属（Callithrix）由两个亚群组成。“奥里塔”（aurita）亚群由两个物种构成，而“狨”（jacchus）亚群的四个物种之间的进化关系仍不明确。为了揭示这些关系，我们首先对库氏狨（C. kuhlii）和彭氏狨（C. penicillata）的线粒体基因组进行测序，以补充其同属物种的现有数据。然后，我们基于几种灵长类动物的线粒体DNA重链蛋白质编码基因构建了系统发育树，以理清物种关系并估计狨亚群的分化时间。
对库氏狨和彭氏狨的线粒体DNA基因组进行桑格测序。将这些狨属有丝分裂基因组与其他公开可用的灵长类动物线粒体DNA基因组相结合。使用最大似然法和贝叶斯推断法构建系统发育树。最后，用贝叶斯推断法估计狨亚群内的分化时间。
在我们构建的系统发育树中，杰氏狨（C. geoffroyi）是所有其他狨亚群物种的姐妹群，其次是库氏狨，而普通狨（C. jacchus）和彭氏狨的分化时间最近。贝叶斯推断表明，普通狨和彭氏狨大约在0.70百万年前分化，狨亚群大约在1.30百万年前辐射分化。
狨属的核基因和线粒体DNA系统发育常常导致多歧分支和并系群。在此，我们基于线粒体基因组序列呈现了一个得到充分支持的系统发育树，这有助于理解狨亚群的分化。我们的结果表明线粒体基因组如何通过缓解先前线粒体DNA研究面临的一些困难来丰富狨属的系统发育研究，并允许提出假设以便在更大规模的基因组分析下进一步检验。
