de Jong Wilfried W, van Dijk Marjon A M, Poux Céline, Kappé Guido, van Rheede Teun, Madsen Ole
Department of Biochemistry, 161 NCMLS, University of Nijmegen, The Netherlands.
Mol Phylogenet Evol. 2003 Aug;28(2):328-40. doi: 10.1016/s1055-7903(03)00116-7.
Despite the availability of large molecular data sets, the position of the root of the eutherian tree remains a controversial issue. Depending on source data, taxon sampling and analytical approach, the root can be placed at either Afrotheria, Xenarthra, Afrotheria+Xenarthra, or murid rodents. We explored the phylogenetic potential of indels in four nuclear protein-coding genes (SCA1, PRNP, TNFalpha, and HspB3) with regard to a possible rooting at the murid branch. According to parsimony principles, five indels were interpreted to contradict such a rooting, and one indel to support it. The results illustrate that indels, despite the occurrence of homoplasy, can be convincing sources of independent molecular evidence to distinguish between alternative phylogenetic hypotheses.
尽管有大量的分子数据集可用，但真兽类谱系树根部的位置仍然是一个有争议的问题。根据源数据、分类群抽样和分析方法的不同，根部可以置于非洲兽总目、异关节总目、非洲兽总目+异关节总目或鼠科啮齿动物处。我们探讨了四个核蛋白编码基因（SCA1、PRNP、TNFalpha和HspB3）中插入缺失在鼠科分支处可能的生根方面的系统发育潜力。根据简约原则，五个插入缺失被解释为与这种生根相矛盾，一个插入缺失则支持这种生根。结果表明，插入缺失尽管存在同塑性，但可以成为区分不同系统发育假说的令人信服的独立分子证据来源。
