Statistical tests between competing hypotheses of Hox cluster evolution.
Statistical tests between competing hypotheses of Hox cluster evolution.
复制标题
Hox 簇演化的竞争假设之间的统计检验。
DOI：
10.1080/10635150802430079
复制
发表时间：
2008
影响因子：
6.5
通讯作者：
L. Bromham
中科院分区：
文献类型：
--
作者：
R. Lanfear;L. Bromham
Hox基因编码的转录因子在迄今为止研究的所有两侧门的前后图案中起着至关重要的作用。此外，通过复制获得Hox基因已被广泛认为是动物身体计划进化的驱动力。正因为如此，重建Hox星系团的演化一直是研究兴趣的焦点。通常认为，一个祖先的四基因ProtoHox簇在动物进化的早期被复制，产生了Hox和ParaHox簇。然而，这一假设最近受到质疑，并提出了一些Hox和ParaHox基因进化的替代假设。在这里，我们提出了第一个统计比较目前的假设Hox和ParaHox基因进化。我们使用两种统计方法，代表两种不同的方法来处理系统发育的不确定性。在第一种方法中，我们估计每个假设的最大似然树，并使用参数自举方法将这些树相互比较。在第二种方法中，我们使用贝叶斯遗传学来估计树的后验分布，然后我们从这个分布中计算每个假设的支持度。两种方法的结果基本一致。我们发现，我们能够拒绝五个目前的Hox和ParaHox基因进化的假设，我们认为。我们的结论是，ProtoHox集群很可能包含三个或四个基因，但在同源结构域中没有足够的系统发育信号来区分这些替代品。
The Hox genes encode transcription factors that play vital roles in the anterior-posterior patterning of all bilaterian phyla studied to date. Additionally, the gain of Hox genes by duplication has been widely implicated as a driving force in the evolution of animal body plans. Because of this, reconstructing the evolution of the Hox cluster has been the focus of intense research interest. It has been commonly assumed that an ancestral four-gene ProtoHox cluster was duplicated early in animal evolution to give rise to the Hox and ParaHox clusters. However, this hypothesis has recently been called into question, and a number of alternative hypotheses of Hox and ParaHox gene evolution have been proposed. Here, we present the first statistical comparisons of current hypotheses of Hox and ParaHox gene evolution. We use two statistical methods that represent two different approaches to the treatment of phylogenetic uncertainty. In the first method, we estimate the maximum-likelihood tree for each hypothesis and compare these trees to one another using a parametric bootstrapping approach. In the second method, we use Bayesian phylogenetics to estimate the posterior distribution of trees, then we calculate the support for each hypothesis from this distribution. The results of both methods are largely congruent. We find that we are able to reject five out of the eight current hypotheses of Hox and ParaHox gene evolution that we consider. We conclude that the ProtoHox cluster is likely to have contained either three or four genes but that there is insufficient phylogenetic signal in the homeodomains to distinguish between these alternatives.