Huang Jie, Luo Xiaotian, Bourland William A, Gao Feng, Gao Shan
Institute of Evolution & Marine Biodiversity, Ocean University of China, Qingdao, China.
Department of Biological Sciences, Boise State University, Boise, USA.
Mol Phylogenet Evol. 2016 Aug;101:101-110. doi: 10.1016/j.ympev.2016.05.007. Epub 2016 May 6.
Phylogenetic analyses of ciliated protozoa have been increasingly relied on multigene information, which was revealed to provide more robust interpretations than single-gene information. Previous studies showed that Amphisiellidae was an extremely divergent group within the order Stichotrichida, with species widely dispersed throughout the stichotrichid assemblage, while Trachelostylidae, excluding gonostomatid species, is a monophyletic group within the order Sporadotrichida. In the present study, we provide 38 new sequences of SSU-rDNA, ITS1-5.8S-ITS2 and LSU-rDNA genes to infer phylogenetic relationships among all taxa available in Amphisiellidae and Trachelostylidae. The results indicate that: (1) Amphisiellidae is polyphyletic, with Amphisiella, Hemiamphisiella, Orthoamphisiella, Uroleptoides, and Urospinula distributing in different clades; (2) Amphisiella is separated into two clades in phylogenetic trees, corroborated by difference in cortical granule distribution. Thus, cortical granule pattern and distribution may be strong diagnostic features to divide Amphisiella species into two subgenera; (3) the monophyly of Trachelostylidae sensu Berger (2008) is strongly supported, suggesting it is a well-defined family; (4) Gonostomatidae is confirmed to be a valid family.
纤毛虫的系统发育分析越来越依赖多基因信息，研究表明多基因信息比单基因信息能提供更可靠的解读。以往研究显示，双毛科是排毛目内一个极度分化的类群，其物种广泛分布于整个排毛类组合中，而除殖口类物种外的尾柱科是散毛目内的一个单系类群。在本研究中，我们提供了38条新的小亚基核糖体DNA（SSU-rDNA）、内转录间隔区1-5.8S-内转录间隔区2（ITS1-5.8S-ITS2）和大亚基核糖体DNA（LSU-rDNA）基因序列，以推断双毛科和尾柱科所有已知分类单元之间的系统发育关系。结果表明：（1）双毛科是多系的，双毛虫属、半双毛虫属、直双毛虫属、类尾柱虫属和尾刺虫属分布在不同的分支中；（2）双毛虫属在系统发育树中分为两个分支，皮层颗粒分布的差异证实了这一点。因此，皮层颗粒模式和分布可能是将双毛虫属物种分为两个亚属的有力诊断特征；（3）强烈支持Berger（2008）定义的尾柱科的单系性，表明它是一个界定明确的科；（4）殖口科被确认为一个有效的科。
