Identification and functional characterization of polymorphisms in promoter sequences of porcine NOD1 and NOD2 genes

Molecular characterisation and function analysis of NOD1 gene from Yangzhou goose (Anser cygnoides domesticus)

1. NOD1 is a significant member of the NOD-like receptor (NLR) family. Its main role is to identify microorganisms that invade the body, transmit immune signals and regulate innate immune responses. However, the expression and role of the NOD1 in immune defence against infection in geese remain unknown.2. The RT-PCR method and rapid amplification of cDNA ends (RACE) was used to obtain the full-length goose NOD1 (gNOD1) cDNA series. The cDNA for gNOD1 contains 2856-bp nucleotides, i.e. 47-bp 5' UTR, 135-bp 3' UTR, and 1275-bp ORF region, and encodes a 951-amino-acids (AAs) polypeptide chain. The nucleotide sequence of gNOD1 was found more than 90% similar to its homologs from other avian organisms.3. The qRT-PCR results showed that gNOD1 mRNA was widely distributed in different tissues, but highly expressed in liver, spleen, lung and caecum tissues.4. Following stimulation of goose embryo fibroblasts (GEFs) with lipopolysaccharide (LPS) and polyriboinosinic polyribocytidylic acid (poly(I:C)), the expression of gNOD1 and cytokines, such as IL-1β, IL-6, IL-18, and TNF-α, changed with the response-efficacy correlation at 24 and 48 h post-infection (hpi).5. When the goslings were challenged with Salmonella entertidis (SE) and LPS, the expression of gNOD1 was up-regulated at 3 and 6 hpi in the spleen and caecum tissues, respectively. However, after SE infection, the expression level of gNOD1 fluctuated, while in the LPS group, gNOD1 mRNA increased immediately at a peak time of 6 hpi and then steadily declined. These results indicated that NOD1 was associated with the potency to resist bacterial and viral infections in the goose, both in vivo and in vitro.