Molecular evolution of ancient TIR containing gene family in innate immunity

为了揭示基底后口中含有信号分子的toll样受体（TLRs）和TIR的序列，我们分析了一种被跟踪的龙眼鱼Metacrinus rotundas的EST，并通过Next基因测序对其胚胎和幼虫的cDNA进行了测序。到目前为止，我们鉴定出6个tlr，由3个蝇型tlr基因和3个脊椎动物型tlr基因组成。在海百合的cDNA中也发现了myd88样基因和sarm样基因，表明这些基因存在于基底后口动物中。我们在海百合的测序数据中发现了独特的含有CARD-TIR和TPR-TIR的基因家族，这些基因家族在海胆基因组中没有，但在文昌鱼基因组中。这些数据表明，基底后口可以利用多基因的tlr和各种类型的含TIR基因。tlr和信号分子的细化可能发生在获得性免疫出现后。

To unveil a repertoire of Toll-like receptors (TLRs) and TIR containing signaling molecules in a basal deuterostome, we analyzed EST of a stalked crinoid, Metacrinus rotundas, whose embryonic and larval cDNA have been sequenced by Next Gene Sequencing. So far, we identified 6 TLRs that consist of 3 genes of fly-type and 3 genes of vertebrate type TLRs. MyD88-like genes and Sarm-like genes were also identified in the cDNA of the sea lily, suggesting these genes exist in a basal deuterostome. We found unique TIR containing gene families, CARD-TIR and TPR-TIR, in the sequencing data of the sea lily, which have not been in the genome of the sea urchin, but in that of amphioxus. These data suggest a basal deuterostome could utilize multigenes of TLRs and various types of TIR containing genes. And the refinement of TLRs and signaling molecules could happen after the appearance of acquired immunity.