Phylogenetic analysis and expression patterns of Pax genes in the onychophoran Euperipatoides rowelli reveal a novel bilaterian Pax subfamily
Phylogenetic analysis and expression patterns of Pax genes in the onychophoran Euperipatoides rowelli reveal a novel bilaterian Pax subfamily
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DOI：
10.1111/ede.12110
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发表时间：
2015-01-01
影响因子：
2.9
通讯作者：
Mayer, Georg
中科院分区：
文献类型：
--
作者：
Franke, Franziska Anni;Schumann, Isabell;Mayer, Georg
Pax家族基因编码一类调节各种发育过程的转录因子。为了阐明这些基因在泛节肢动物（Onychophora+缓步动物+节肢动物）的进化历史，我们分析了Pax剧目的胚胎和成人的onychophoran Euperipatoides rowelli的转录组。我们的数据显示，所有五个主要的双侧Pax亚科在这个物种，包括Pax 2/5/8，Pax 4/6，Pox-neuro，Pax 1/9/Pox-meso，和Pax 3/7的同源物。此外，我们确定了一个新的Pax成员，Pax-，它不属于任何其他已知的Pax亚科，而是集群在异源Pax-/含有后口动物，ecdysozoan，和lophotrochozoan基因序列的分支。这些发现表明，最后一个共同的双侧祖先拥有六个而不是五个Pax基因，这些基因在泛节肢动物谱系中保留下来。Pax直系同源基因在onychophoran胚胎中的表达数据揭示了独特的模式，其中一些可能与它们在最后一个共同的泛节肢动物祖先中的祖先角色有关，而另一些可能是特定于onychophoran谱系的。衍生的角色包括，例如，参与pax 2/5/8，痘神经，和pax 3/7 onychophoran nephridiogenesis，和一个额外的功能pax 2/5/8的腹侧和preventral器官的形成。此外，我们的转录组学分析表明，至少有一些Pax基因，包括pax 6和pax-，在成年的onychophoran头中表达，虽然相应的功能仍有待澄清。Pax表达模式的显着多样性凸显了这些基因在泛节肢动物中的功能和进化可塑性。
Pax family genes encode a class of transcription factors that regulate various developmental processes. To shed light on the evolutionary history of these genes in Panarthropoda (Onychophora+Tardigrada+Arthropoda), we analyzed the Pax repertoire in the embryonic and adult transcriptomes of the onychophoran Euperipatoides rowelli. Our data revealed homologs of all five major bilaterian Pax subfamilies in this species, including Pax2/5/8, Pax4/6, Pox-neuro, Pax1/9/Pox-meso, and Pax3/7. In addition, we identified a new Pax member, pax-, which does not fall into any other known Pax subfamily but instead clusters in the heterogenic Pax-/ clade containing deuterostome, ecdysozoan, and lophotrochozoan gene sequences. These findings suggest that the last common bilaterian ancestor possessed six rather than five Pax genes, which have been retained in the panarthropod lineage. The expression data of Pax orthologs in the onychophoran embryo revealed distinctive patterns, some of which might be related to their ancestral roles in the last common panarthropod ancestor, whereas others might be specific to the onychophoran lineage. The derived roles include, for example, an involvement of pax2/5/8, pox-neuro, and pax3/7 in onychophoran nephridiogenesis, and an additional function of pax2/5/8 in the formation of the ventral and preventral organs. Furthermore, our transcriptomic analyses suggest that at least some Pax genes, including pax6 and pax-, are expressed in the adult onychophoran head, although the corresponding functions remain to be clarified. The remarkable diversity of the Pax expression patterns highlights the functional and evolutionary plasticity of these genes in panarthropods.