Jiji Li

Molecular characterization and expression analysis of a complement component C3 in large yellow croaker (Larimichthys crocea)

The complement system has been discovered in invertebrates and vertebrates, and plays a crucial role in the innate defense against common pathogens. Complement component 3 is a key molecule in the complement system, whose activation is essential for all the important functions performed by this system. In this study, the complete C3 cDNA sequence was isolated from the large yellow croaker (Larimichthys crocea), which was high similarity to other complement C3. We reported the primary sequence, tissue expression profile, polypeptide domain architecture and phylogenetic analysis of L. crocea complement component C3 (L.c-C3) gene. Its open reading frame (ORF) is 4962 bp and encodes for 1653 amino acids with a putative signal peptide of 23 amino acid residues. The deduced amino acid sequence showed that L.c-C3 has conserved residues and domains known to be crucial for C3 function. Phylogenetic analysis showed that L. crocea was closely related to Miichthys miiuy. The mRNA expressions of L.c-C3 was detectable at different tissues. L.c-C3 was expressed in a wide range of adult tissues, it showed highest expression in the liver. But the different developmental stages from fertilized egg to newborn larvae of the large yellow croaker the highest expression levels of L.c-C3 gene were not found. Bacterial challenge experiments showed that the levels of L.c-C3 mRNA expression were up-regulated in the liver, spleen and brain of adult large yellow croaker respectively. The results showed that L.c-C3 mRNA expression in the large yellow croaker is influenced by bacterial stress and L.c-C3 might play an important role in immunity mechanisms. This study will further increase our understanding of the function of L.c-C3 and molecular mechanism of innate immunity in teleosts.

Molecular characterization of complement component 3 (C3) in Mytilus coruscus improves our understanding of bivalve complement system

&NA; Complement component 3 (C3) plays a central role in the complement system whose activation is essential for all the important functions performed by this system. Here, a novel C3 gene, termed Mc‐C3, was identified from thick shell mussel (Mytilus coruscus). The deduced Mc‐C3 protein possessed the characteristic structure features present in its homologs and contained the A2M_N_2, ANATO, A2M, A2M_comp, A2M_recep, and C345C domains, as well as the C3 convertase cleavage site, thioester motif, and conserved Cys, His, and Glu residues. Mc‐C3 gene constitutively expressed in all examined tissues and predominantly expressed in immune‐related tissues such as gills, hemocytes and hepatopancreas. After stimulation with lipopolysaccharide or Cu2+, the expression of Mc‐C3 was significantly induced in gills. Further luciferase reporter assays showed the ability for activation of NF‐&kgr;B signaling transduction of Mc‐C3a. Taken together, these results show that C3 may play an essential role in the immune defense of M. coruscus. The present data therefore provide a more detailed insight into the functional activities of the bivalve complement system. HighlightsThe novel complement component 3 gene was identified from M. coruscus.Mc‐C3 gene constitutively expressed in all examined tissues.Mc‐C3 was significantly induced in gills with LPS and Cu2+ stimulations.Mc‐C3a could activate the NF‐&kgr;B signaling transduction.

Complete mitochondrial genome of the spineless cuttlefish Sepiella inermis (Sepioidea, Sepiidae)

Abstract In this study, we determined the complete mitochondrial genome of the spineless cuttlefish Sepiella inermis. The genome was 16,191 bp in length and contained 13 protein-coding genes, 22 transfer RNA genes, 2 ribosomal RNA genes, and 2 main non-coding regions [both are control regions (CR)]. The composition and order of genes, for the mitogenome found in S. inermis were similar to most other invertebrates. The overall base composition of S. inermis is T 35.6%, C 16.4%, A 40.0% and G 8.0%, with a highly A + T bias of 75.6%. Two control regions contain both termination-associated sequences and conserved sequence blocks. Thus, mitogenome sequence data would play an important role in the investigation of phylogenetic relationship, taxonomic resolution and phylogeography of the Sepiidae.

Complete mitochondrial genome of the common cuttlefish Sepia pharaonis (Sepioidea, Sepiidae)

Abstract In this study, the complete mitochondrial genome of the common cuttlefish Sepia pharaonis was determined first. The genome was 16,208 bp in length and contained 13 protein-coding genes, 22 transfer RNA genes, 2 ribosomal RNA genes and 2 main non-coding regions [both are control regions (CR)], the gene composition and order of which were similar to most other invertebrates. The overall base composition of S. pharaonis is T: 36.3%, C: 14.7%, A: 40.9% and G: 8.1%, with a hightly A + T bias of 77.2%. Two control regions all contain termination-associated sequences and conserved sequence blocks. This mitogenome sequence data would play an important role in the investigations of the phylogenetic relationships, taxonomic resolution and phylogeography of the Sepiidae.

Identification and functional characterization of three myeloid differentiation factor 88 (MyD88) isoforms from thick shell mussel Mytilus coruscus

Abstract Myeloid differentiation factor 88 (MyD88) is a pivotal adapter protein that involved in interleukin‐1 receptor/toll‐like receptor (IL‐1R/TLR) signal transduction, which could spur downstream cascades and eventually drawn into innate immune response. MyD88 has been extensively studied in vertebrates, however, the information ascribe to MyD88 in invertebrates is still very scarce especially its function annotation remains extremely obscure. At here, three novel MyD88 isoforms termed McMyD88a, McMyD88b and McMyD88c were firstly cloned from thick shell mussel Mytilus coruscus. McMyD88a, McMyD88b and McMyD88c shared domain topology containing the Death domain (DD) and TIR domain (TIR) with its counterparts in mammals. All three McMyD88s were ubiquitously expressed in examined tissues in thick shell mussel, with the higher expression levels in immune‐related tissues such as haemocytes, gills and digestive glands. Upon Vibrio alginolyticus, polyinosine‐polycytidylic acid (poly I:C) and lipopolysaccharide (LPS) challenge, McMyD88a, McMyD88b and McMyD88c transcripts were significantly induced in haemocytes despite of differential expression levels and responsive time points. Overexpression of McMyD88a, McMyD88b and McMyD88c showed a dose‐dependent induction to NF‐&kgr;B or ISRE in mammalian cell lines. Taken together, these results suggested that McMyD88a, McMyD88b and McMyD88c are members of MyD88 family and play potential roles in innate immune response to pathogenic invasions in thick shell mussel. Moreover, these results suggested indirectly the existence of a MyD88‐dependent signaling pathway in thick shell mussel, and provide insight into the immunoregulatory effect in molluscs. HighlightsThree novel MyD88 isoforms firstly characterized in M. coruscus.All three MyD88s shared domain topology containing the DD and TIR domains.Transcriptional levels of all three MyD88s up‐regulated in haemocytes upon V. alginolyticus, LPS and poly I:C challenge.Overexpressed McMyD88a, McMyD88b and McMyD88c could induce the activation of NF‐&kgr;B or ISRE.Suggested indirectly the existence of a MyD88‐dependent signaling pathway in thick shell mussel.

Corrigendum to “Anti-infective mannose receptor immune mechanism in large yellow croaker (Larimichthys crocea)” [Fish Shellfish Immunol. 54 (2016 Jul) 257–265]

Corrigendum to “Anti-infective mannose receptor immune mechanism in large yellow croaker (Larimichthys crocea)” [Fish Shellfish Immunol. 54 (2016 Jul) 257e265] Xiangli Dong , Jiji Li a, b, , Jianyu He , Wei Liu , Lihua Jiang , Yingying Ye , Changwen Wu a, * a National Engineering Research Center of Maricultural Facilities of China, College of Marine Science and Technology, Zhejiang Ocean University, Haida South Road 1, 316022, Zhoushan, Zhejiang, PR China b Universita degli Studi di Napoli “Federico II”, Parco Gussone 1, 80055, Portici, Naples, Italy c Enea CR Portici, P. le E. Fermi, 1, 80055, Portici, Naples, Italy