Molecular characterization of three toll-like receptors (TLR21, TLR22, and TLR25) from a primitive ray-finned fish Dabry's sturgeon (Acipenser dabryanus)
Molecular characterization of three toll-like receptors (TLR21, TLR22, and TLR25) from a primitive ray-finned fish Dabry's sturgeon (Acipenser dabryanus)
复制标题
DOI：
10.1016/j.fsi.2018.08.033
复制
发表时间：
2018-11-01
影响因子：
4.7
通讯作者：
Wei, Qiwei
中科院分区：
文献类型：
--
作者：
Qi, Zhitao;Wang, Sisi;Wei, Qiwei
达布里鲟（Acipenser dabryanus）是研究鱼类进化的有用模型，因为它是最原始的放线鱼物种之一。然而，对这种鱼免疫系统的研究有限。在这里，我们从达布里鲟中鉴定出三种 Toll 样受体（adaTLR21、adaTLR22 和 adaTLR25）。三个鲟鱼 TLR 具有特有的 TLR 特征，包括信号肽、几个富含亮氨酸的重复 (LRR) 结构域、跨膜结构域和 Toll/白细胞介素-1 受体 (TIR) 结构域。尽管由鲟鱼 adaTLR21、adaTLR22 和 adaTLR25 编码的预测氨基酸序列与其他鱼类 TLR 的序列同一性和相似性水平较低，但这三种鲟鱼 TLR 与我们的邻近连接系统发育树中的其他硬骨鱼 TLR 属于得到良好支持的进化枝。实时定量PCR表明，这三种鲟鱼TLR在健康成年鲟的所有检查组织中普遍表达，但它们的表达模式在不同组织之间差异很大。这三种鲟鱼 TLR 在所检查的所有胚胎发育阶段都有表达，但它们的表达水平在不同发育阶段有所不同。在脂多糖 (LPS) 和聚肌苷：聚胞苷酸 (polyI:C) 刺激后，头肾原代白细胞中所有三种 TLR 均上调。据我们所知，这是达比鲟中这三个 TLR 的首次表征。我们的研究结果为进一步研究鲟鱼中 TLR 配体特异性和信号通路提供了框架，并增加了我们对脊椎动物 TLR 功能进化的理解。
Dabry's sturgeon (Acipenser dabryanus) is a useful model for the study of fish evolution, as it is one of the most primitive actinopterygian species. However, studies of the immune system of this fish are limited. Here, we identified three toll-like receptors (adaTLR21, adaTLR22, and adaTLR25) from Dabry's sturgeon. The three sturgeon TLRs had characteristic TLR features, including a signal peptide, several leucine rich repeat (LRR) domains, a transmembrane domain, and a Toll/interleukin-1 receptor (TIR) domain. Although the predicted amino acid sequences encoded by the sturgeon adaTLR21, adaTLR22, and adaTLR25 had somewhat low levels of sequence identity and similarity with TLRs from other fish species, the three sturgeon TLRs fell in well-supported clades with other teleost TLRs in our neighbor-joining phylogenetic tree. Real-time quantitative PCR showed that the three sturgeon TLRs were ubiquitously expressed in all examined tissues from healthy adult sturgeon, but that their expression patterns varied greatly among the different tissues. The three sturgeon TLRs were also expressed across all embryonic developmental stages that were examined, but their expression levels differed between developmental stages. All three TLRs were upregulated in head-kidney primary leucocytes following lipopolysaccharide (LPS) and polyinosinic: polycytidylic acid (polyI:C) stimulation. To the best of our knowledge, this is the first characterization of these three TLRs in Darby's sturgeon. Our results provide a framework for further studies of TLR ligand specificity and signaling pathways in sturgeon, and increase our understanding of the functional evolution of TLRs in vertebrates.