title: Characterization of NLR-A subfamily members in miiuy croaker and comparative genomics revealed NLRX1 underwent duplication and lose in actinopterygii.
abstract: The NOD-like receptors (NLRs, nucleotide-binding domain and leucine-rich repeat containing receptors) are a recently identified family of intracellular pathogen recognition receptors in vertebrates. Several subfamilies of NLRs have been characterized in mammals and implicated in immunity and apoptosis, but studies of NLRs in teleost species have been lacking. Here we analyzed three NLR-A subfamily members from miiuy croaker: NLRC3, NLRC5, and NLRX1. Structural analysis showed that miiuy croaker NLR-A subfamily members own the feature of 5'UTR intron which may influence their role in enhancing translation level. Comparative analysis revealed NLRX1 duplicated into NLRX1a and NLRX1b, then NLRX1a was lost in actinopterygii and NLRX1b formed NLRX1 that now we called. Simultaneously, molecular evolutionary analysis indicated that the ancestral lineages of NLRX1 in tetrapod and actinopterygii under positive selection pressure. The positively sites in actinopterygii are mainly located in NACHT domain which was the critical region for signal transduction, suggesting that the evolution of NLRX1 gene in the ancestor of actinopterygii is beneficial in immune response. Pathogens challenge demonstrated that the expressions of NLRC3 and NLRC5 in miiuy croaker were induced not only by Vibrio anguillarum but also by poly (I:C), whereas NLRX1 exhibited more sensitive response to bacteria than virus.
authors.affiliation: Laboratory of Fish Biogenetics & Immune Evolution, College of Marine Science, Zhejiang Ocean University, Zhoushan, 316022, China.
authors.forename: Jinrui
authors.initials: J
authors.lastname: Li
authors.affiliation: College of Animal Science and Veterinary Medicine, Jilin Agriculture University, Changchun, 130118, China.
authors.forename: Lingcong
authors.initials: L
authors.lastname: Kong
authors.affiliation: College of Animal Science and Veterinary Medicine, Jilin Agriculture University, Changchun, 130118, China.
authors.forename: Yunhang
authors.initials: Y
authors.lastname: Gao
authors.affiliation: National Engineering Research Center of Marine Facilities Aquaculture, Zhejiang Ocean University, Zhoushan, 316022, China. Electronic address: wucwzjou@163.com.
authors.forename: Changwen
authors.initials: C
authors.lastname: Wu
authors.affiliation: Laboratory of Fish Biogenetics & Immune Evolution, College of Marine Science, Zhejiang Ocean University, Zhoushan, 316022, China. Electronic address: tianjunxu@163.com.
authors.forename: Tianjun
authors.initials: T
authors.lastname: Xu
mesh_terms: D000595:Amino Acid Sequence; D000818:Animals; D019143:Evolution, Molecular; D005393:Fish Diseases / Q000235:genetics* / Q000276:immunology / Q000382:microbiology; D029941:Fish Proteins / Q000737:chemistry / Q000235:genetics* / Q000378:metabolism; D010473:Perciformes; D010802:Phylogeny; D011070:Poly I-C / Q000494:pharmacology*; D016415:Sequence Alignment / Q000662:veterinary; D026801:Synteny; D014733:Vibrio / Q000502:physiology*; D014735:Vibrio Infections / Q000235:genetics / Q000276:immunology / Q000382:microbiology / Q000662:veterinary*
chemical_list: D029941:Fish Proteins; D011070:Poly I-C
keywords: Evolution analysis; Expression pattern; Gene duplication; NLR-A