PDF(Pubmed)
Abstract：
Aquaporins (AQPs) are a family of membrane channels facilitating diffusion of water and small solutes into and out of cells. Despite their biological relevance in osmoregulation and ubiquitous distribution throughout metazoans, the presence of AQPs in annelids has been poorly investigated. Here, we searched and annotated Aqp sequences in public genomes and transcriptomes of annelids, inferred their evolutionary relationships through phylogenetic analyses and discussed their putative physiological relevance. We identified a total of 401 Aqp sequences in 27 annelid species, including 367 sequences previously unrecognized as Aqps. Similar to vertebrates, phylogenetic tree reconstructions clustered these annelid Aqps in four clades: AQP1-like, AQP3-like, AQP8-like and AQP11-like. We found no clear indication of the existence of paralogs exclusive to annelids; however, several gene duplications seem to have occurred in the ancestors of some Sedentaria annelid families, mainly in the AQP1-like clade. Three of the six Aqps annotated in Alitta succinea, an estuarine annelid showing high salinity tolerance, were validated by RT-PCR sequencing, and their similarity to human AQPs was investigated at the level of \"key\" conserved residues and predicted three-dimensional structure. Our results suggest a diversification of the structures and functions of AQPs in Annelida comparable to that observed in other taxa.
摘要：
水通道蛋白(AQP)是促进水和小溶质进出细胞的扩散的膜通道家族。尽管它们在渗透调节和整个后生动物普遍存在的分布中具有生物学相关性，对环节动物中AQPs的存在研究甚少。这里,我们在环节动物的公共基因组和转录组中搜索并注释了Aqp序列，通过系统发育分析推断它们的进化关系，并讨论了它们推定的生理相关性。我们在27个环节动物物种中总共鉴定出401个Aqp序列，包括以前未识别为Aqps的367个序列。类似于脊椎动物，系统发育树重建将这些环状Aqps聚集在四个分支中：AQP1样，类似AQP3，AQP8样和AQP11样。我们没有发现明确的迹象表明存在环节动物专有的旁系同源物；然而，一些Sedentaria环节动物家族的祖先似乎发生了几个基因重复，主要在AQP1样进化枝。在Alittasuccinea注释的六个Aqps中的三个，一种表现出高耐盐性的河口环节动物，通过RT-PCR测序验证，在“关键”保守残基和预测的三维结构水平上研究了它们与人类AQPs的相似性。我们的结果表明，与其他分类群相比，Annelida中AQP的结构和功能多样化。
