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arXiv 1208.3606q-bio.PEstat.AP
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不完全谱系分类下异源多倍体物种网络的统计推断

Statistical Inference of Allopolyploid Species Networks in the Presence of Incomplete Lineage Sorting

Graham Jones, Serik Sagitov, Bengt Oxelman

摘要:

多倍体是一种重要的物种形成机制,特别是在陆地植物中。异源多倍体物种是在不育亲本物种之间杂交后形成的。最近的理论进展导致成功实施的物种树模型,考虑到人口遗传参数。然而,这些模型没有包括异源多倍体杂交和异源多倍体物种树推断时所施加的特殊问题。在这里,两个新的模型的异源多倍体的进化历史的统计推断进行评估,使用模拟和两个经验数据集上证明。假设两个二倍体物种之间存在单一杂交事件,导致基因组异源四倍体。进化历史可以表示为一个网络或一个多标记树,其中一些对尖端被标记为相同的物种。在其中一个模型(AlloppMUL)中,直接推断多重标记树。这是最简单的模型,也是最广泛适用的模型,因为所做的假设较少。第二个模型(AlloppNET)明确地结合了杂交事件,这意味着需要估计的参数更少。这两个模型都在BEAST框架中实现。模拟表明,这两种模型都是有用的,如果它所基于的假设是有效的,AlloppNET是更准确的。该模型表明,以前分析的数据从属Pachycladon(菊科)和属蝇子草(石竹科)。

英文摘要:

Polyploidy is an important speciation mechanism, particularly in land plants. Allopolyploid species are formed after hybridization between otherwise intersterile parental species. Recent theoretical progress has led to successful implementation of species tree models that take population genetic parameters into account. However, these models have not included allopolyploid hybridization and the special problems imposed when species trees of allopolyploids are inferred. Here, two new models for the statistical inference of the evolutionary history of allopolyploids are evaluated using simulations and demonstrated on two empirical data sets. It is assumed that there has been a single hybridization event between two diploid species resulting in a genomic allotetraploid. The evolutionary history can be represented as a network or as a multiply labeled tree, in which some pairs of tips are labeled with the same species. In one of the models (AlloppMUL), the multiply labeled tree is inferred directly. This is the simplest model and the most widely applicable, since fewer assumptions are made. The second model (AlloppNET) incorporates the hybridization event explicitly which means that fewer parameters need to be estimated. Both models are implemented in the BEAST framework. Simulations show that both models are useful and that AlloppNET is more accurate if the assumptions it is based on are valid. The models are demonstrated on previously analyzed data from the genus Pachycladon (Brassicaceae) and from the genus Silene (Caryophyllaceae).

机构、总结、中文摘要均由AI分析而来,可能存在错误,请以论文正文为准。

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