Molecular Cloning And Tissues Expression Profile Of Goose TLR2-1and15Gene

Toll-like receptors (TLRs) are considered as key sensors to trigger the host’s innateimmune system and adaptive immune responses by recognizing various PAMPs andinitiating signal transduction. TLRs have a central role in innate immunity and are alsorequired for the development of an adaptive immune response, bridging innate andadaptive immunity. The present study was conducted to explore the potential role of Tolllike receptor on the goose immunity, and accumulate alternative genetic material for thegoose breeding for disease-resistant. We cloned the cDNA of TLR2-1and15by RT-PCR,SMART-RACE in MaGang goose, as well their expression profile in different tissue byqRT-PCR. The results showed that:（1）The cloned goose TLR2-1full length cDNA exhibited3119bp in length,including a5′-terminal (UTR) of359bp, a3′-terminal (UTR) of378bp and an openreading frame (ORF) of2382bp encoding793amino acides has a calculated molecularmass of90.17kDa, a theoretical pI of7.73, and a putative signal secretion peptide33aain its N-terminal region. Structurally, TLR2-1has a Toll/interleukin-receptor (TIR)domain, a transmembrane domain and9leucine-rich repeats (LRRs) domain which arethe hallnarks of TLR family. The leucine-rich domain (LRR) and interleukin-1receptordomain (TIR) were conserved in goose TLR2-1. Homology alignment of TLR2-1and itsTIR domains revealed that goose TLR2-1shared high percentage of identities with otherspecials (39.6-84.6%). By quantitative RT-PCR, we founded that the TLR2-1gene ofgoose was broadly expressed in all tested tissues. However, the expression levels differednoticeably among the tissues, with the highest expression in kidney, cloacal bursa, skinand brain.(2) The cloned goose TLR15full length cDNA exhibited2805bp in length,including a5′-terminal (UTR) of114bp, a3′-terminal (UTR) of93bp and an openreading frame (ORF) of2598bp encoding865amino acides and has a calculatedmolecular mass of98.85kDa, a theoretical pI of7.25and a putative signal secretionpeptide22aa in its N-terminal region. Structurally, TLR15has a Toll/interleukin-receptor(TIR) domain, a transmembrane domain and6leucine-rich repeats (LRRs) domain whichare the hallnarks of TLR family. The leucine-rich domain (LRR) and interleukin-1receptor domain (TIR) were conserved in goose TLR15. Homology alignment of TLR15and its TIR domains revealed that goose TLR15shared highest percentage of identities with Gallus Gallus TLR15(83%). By quantitative RT-PCR, we founded that the TLR15gene of goose was broadly expressed in all tested tissues. However, the expression levelsdiffered noticeably among the tissues, with the highest expression in muscular stomachand muscle.