LAUSR

&NA; Nucleotide‐binding oligomerization domain 1 (NOD1) is an imperative cytoplasmic pattern recognition receptor (PRR) and considered as a key member of the NOD‐like receptor (NLR) family which plays a critical role in innate immunity through sensing microbial components derived from bacterial peptidoglycan. In the current study, the full‐length of duck NOD1 (duNOD1) cDNA from duck embryo fibroblasts (DEFs) was cloned. Multiple sequence alignment and phylogenetic analysis demonstrated that duNOD1 exhibited a strong evolutionary relationship with chicken and rock pigeon NOD1. Tissue‐specific expression analysis showed that duNOD1 was widely distributed in various organs, with the highest expression observed in the liver. Furthermore, duNOD1 overexpression induced NF‐&kgr;B activation in DEFs and the CARD domain is crucial for duNOD1‐mediated NF‐&kgr;B activation. In addition, silencing the duNOD1 decreased the activity of NF‐&kgr;B in DEFs stimulated by iE‐DAP. Overexpression of duNOD1 significantly increased the expression of TNF‐&agr;, IL‐6, and RANTES in DEFs. These findings highlight the crucial role of duNOD1 as an intracellular sensor in duck innate immune system. HighlightsduNOD1 is widely expressed in different tissues.The CARD domain of duNOD1 is essential for the NF‐&kgr;B activation.Knockdown of duNOD1 blocks the activation of NF‐&kgr;B in DEFs.