Toll-like receptors (TLRs) play an important role in detecting pathogen-associated molecular patterns (PAMPs). Among the TLRs, TLR7 is involved in the recognition of antiviral compounds and single-stranded RNA. This study was designed to explore the structure and function of TLR7 in duck (Anas platyrhynchos), a natural host for avian influenza virus. Firstly, the full-length cDNA of Shaoxing egg-laying duck TLR7 (duTLR7) was obtained using reverse transcription-polymerase chain reaction (RT-PCR) and rapid amplification of cDNA ends (RACE). It consisted of 38 base pairs (bp) 5′-untranslated region (UTR), 187 bp 3′-UTR, and 3270 bp open reading frame that encodes a single protein of 1089 amino acid residues. DuTLR7 shares high identity with TLR7 genes from other vertebrates. In healthy ducks, duTLR7 transcripts were broadly expressed in different tissues, with higher expression levels in the liver, kidney, and thymus. The highest relative transcript level of duTLR7 could be induced with R848 stimulation. In addition, overexpression of duTLR7 by stimulating with poly(I:C) significantly promoted IFN-β, NF-κB, IRF7, TRIF, Mx, STAT1 and STAT2 expressions. Taken together, these results suggest that TLR7 may play an important role in the innate immune response of ducks.

Toll 样受体 (TLR) 在检测病原体相关分子模式 (PAMP) 中发挥重要作用。在 TLR 中，TLR7 参与识别抗病毒化合物和单链 RNA。本研究旨在探讨鸭 ( Anas platyrhynchos ) 中 TLR7 的结构和功能。)，禽流感病毒的天然宿主。首先，通过逆转录聚合酶链反应（RT-PCR）和cDNA末端快速扩增（RACE）获得绍兴产蛋鸭TLR7（duTLR7）的全长cDNA。它由 38 个碱基对 (bp) 5'-非翻译区 (UTR)、187 bp 3'-UTR 和 3270 bp 开放阅读框组成，编码 1089 个氨基酸残基的单个蛋白质。DuTLR7 与其他脊椎动物的 TLR7 基因具有高度同一性。在健康鸭中，duTLR7 转录本在不同组织中广泛表达，在肝脏、肾脏和胸腺中的表达水平较高。用 R848 刺激可以诱导 duTLR7 的最高相对转录水平。此外，通过用 poly(I:C) 刺激过表达 duTLR7 显着促进了 IFN-β、NF-κB、IRF7、TRIF、Mx、STAT1 和 STAT2 的表达。