Time filter

Source Type

Mo Z.,Chinese Academy of Fishery Sciences | Mo Z.,National Laboratory for Marine Science and Technology | Li S.,Ocean University of China | Kong F.,Ocean University of China | And 3 more authors.
Journal of Applied Phycology | Year: 2015

This study investigated a new fungal disease that attacks Pyropia yezoensis, an economically important red alga that is extensively cultured in China. An incidence was found in a P. yezoensis farm during mid to end November 2012 at Haizhou Bay, Jiangshu Province, China. Histopathology revealed that the naturally infected thalli were overwhelmed by a fungus, leading to progressive red rot symptoms. The causative agent was isolated, grown in pure culture, and identified as a member of the genus Alternaria by morphology and sequence analysis of the nuclear ribosomal DNA containing the internal transcribed spacer (ITS) region of ITS1 and ITS2. In artificial infection experiments on P. yezoensis blades, the fungal isolate was able to cause the same characteristic histopathology seen in natural infections. This fungal isolate grew well at a wide range of temperatures (8–36 °C) and at low salinities (5–50 ‰). In an orthogonal test used to determine the effects of environmental factors (temperature, salinity, and conidia concentration) on disease expansion, it was found that higher temperatures and lower salinities easily caused red rot disease, with the optimal conditions for disease development being 23 °C, 24 ‰ salinity, and a conidia concentration of 105 mL−1. This is the first report to show that Alternaria causes red rot disease in P. yezoensis. © 2015 Springer Science+Business Media Dordrecht

Li J.,Chinese Academy of Fishery Sciences | Li J.,National Laboratory for Marine Science and Technology | Mo Z.,Chinese Academy of Fishery Sciences | Mo Z.,National Laboratory for Marine Science and Technology | And 5 more authors.
Fish and Shellfish Immunology | Year: 2015

Edwardsiella tarda is an intracellular pathogen that causes edwardsiellosis in fish. The development of a live attenuated vaccine may be an effective approach for preventing this disease in fish. In this study, we introduced deletions of esrB, esaC, evpH, rpoS, and purA into the E.tarda LSE40δaroA strain, thereby generating five double-gene mutants (δaroAδesrB, δaroAδesaC, δaroAδrpoS, δaroAδevpH, and δaroAδpurA) and two triple-gene mutants (δaroAδesrBδevpH and δaroAδesaCδevpH). When blue gourami (Trichogaster trichopterus) was used as a fish model for the primary screening and evaluation of the vaccine candidates, all mutants were attenuated significantly by more than 2 to 3 logs in terms of the 50% lethal dose (LD50). Five double-gene mutants yielded relative percentage survival (RPS) rates of 26.1-82.6% after challenge with wild-type E.tarda. The δaroAδesrB mutant that conferred the highest RPS (82.6%) in blue gourami was also evaluated in flounder (Paralichthys olivaceus). After vaccination via intramuscular (i.m.) injection or immersion, this mutant could persist in the flounder for 14-35 days and it induced higher serum antibody titers than the control fish (P<0.01). Flounder vaccinated via i.m. injection at doses of 103-107CFU/fish had RPS rates of 14.3-66.7% after i.m. challenge with 104CFU/fish using wild-type E.tarda. Flounder vaccinated via immersion at a dose of 107CFU/ml exhibited 100% RPS against immersion challenge with 107CFU/ml using wild-type E.tarda. These results indicate that the δaroAδesrB mutant could be used as an effective live vaccine to combat edwardsiellosis in flounder. © 2015 .

Liu Q.-H.,Chinese Academy of Fishery Sciences | Liu Q.-H.,National Laboratory for Marine Science and Technology | Ma F.-F.,Chinese Academy of Fishery Sciences | Ma F.-F.,Shanghai Ocean University | And 8 more authors.
Fish and Shellfish Immunology | Year: 2015

The interaction between viral structural proteins and host plays key functions in viral infection. In previous studies, most research have been undertaken to explore the interaction of envelope structural proteins with host molecules. However, how the nucleocapsid proteins of WSSV interacted with host molecules remained largely unknown. In this study, the interaction of nucleocapsid protein VP51 and ribosomal protein L7 of Litopenaeus vannamei (LvRPL7) was reported. Furthermore, the mRNA transcriptional response of LvRPL7 to WSSV was investigated. The results showed that LvRPL7 was widely distributed in all analyzed tissues of L. vannamei. The high expression levels of LvRPL7 were found in the tissues of muscle and gills. The temporal expression of LvRPL7 in WSSV-challenged shrimp showed that LvRPL7 was up-regulated (P<0.5) in the muscle at 8h and 24h post WSSV challenge and then restored to the normal levels. But the LvRPL7 expression was up-regulated (P<0.5) in the hepatopancreas at 8h post WSSV challenge and down-regulated at 12h and 24h post WSSV challenge. Indirect immunofluorescence assay indicated that LvRPL7 was mainly located on the surface and cytoplasm of hemocytes. Far-Western blotting showed that VP51 bound with LvRPL7. Moreover, ELISA results appeared that LvRPL7 interacted with VP51 in concentration dependent manner. Neutralization assay invivo showed that anti-LvRPL7 antibody significantly delayed WSSV infection. Our results reveal that LvRPL7 was involved in WSSV infection. © 2015 Elsevier Ltd.

Liu P.-F.,Chinese Academy of Fishery Sciences | Liu P.-F.,Dalian Ocean University | Liu Q.-H.,Chinese Academy of Fishery Sciences | Liu Q.-H.,National Laboratory for Marine Science and Technology | And 3 more authors.
Journal of Invertebrate Pathology | Year: 2015

Thioredoxin (TRX), a major intracellular antioxidant, has a wide range of biological functions. It was up-regulated and targeted by WSSV. However, the relevance of TRX with WSSV infection and signaling pathway remains largely unknown. Sequence analysis indicated that TRX might interact with the WSSV030 (VP362) and WSSV454 (thymidine kinase-thymidylate kinase, TK-TMK) of WSSV. In this study, TRX, VP362 and TK-TMK were expressed and the interaction of TRX with VP362 or TK-TMK was investigated. Furthermore, how TRX affect the process of WSSV infection and the gene transcription of inhibitor of nuclear factor kappa-B kinase (IKK), a p38 mitogen-activated protein kinase (LvP38) and signal transducer and activator of transcription (STAT) in the hemocytes and hepatopancreas was explored. Far-western blot and enzyme-linked immuno assay (ELISA) results showed that TRX interacted with VP362 and TK-TMK. The mRNA expressions of IKK, LvP38 and STAT were significantly affected by the over-presence of TRX of Litopenaeus vannamei. Neutralization experiment in vivo indicated that TRX induced the transcription expression of VP28 and increased the viral copy numbers in the early stage of WSSV infection and it may attribute to the death of shrimps infected by WSSV. © 2015 Elsevier Inc.

Huang L.,CAS Qingdao Institute of Oceanology | Huang L.,University of Chinese Academy of Sciences | Huang L.,Qingdao University | Li G.,Chinese Academy of Fishery Sciences | And 8 more authors.
PLoS ONE | Year: 2015

Background: Japanese flounder (Paralichthys olivaceus) is an economically important marine fish in Asia and has suffered from disease outbreaks caused by various pathogens, which requires more information for immune relevant genes on genome background. However, genomic and transcriptomic data for Japanese flounder remain scarce, which limits studies on the immune system of this species. In this study, we characterized the Japanese flounder spleen transcriptome using an Illumina paired-end sequencing platform to identify putative genes involved in immunity. Methodology/Principal Findings: A cDNA library from the spleen of P. olivaceus was constructed and randomly sequenced using an Illumina technique. The removal of low quality reads generated 12,196,968 trimmed reads, which assembled into 96,627 unigenes. A total of 21,391 unigenes (22.14%) were annotated in the NCBI Nr database, and only 1.1% of the BLASTx top-hits matched P. olivaceus protein sequences. Approximately 12,503 (58.45%) unigenes were categorized into three Gene Ontology groups, 19,547 (91.38%) were classified into 26 Cluster of Orthologous Groups, and 10,649 (49.78%) were assigned to six Kyoto Encyclopedia of Genes and Genomes pathways. Furthermore, 40,928 putative simple sequence repeats and 47, 362 putative single nucleotide polymorphisms were identified. Importantly, we identified 1,563 putative immune-associated unigenes that mapped to 15 immune signaling pathways. Conclusions/Significance The P. olivaceus transciptome data provides a rich source to discover and identify new genes, and the immune-relevant sequences identified here will facilitate our understanding of the mechanisms involved in the immune response. Furthermore, the plentiful potential SSRs and SNPs found in this study are important resources with respect to future development of a linkage map or marker assisted breeding programs for the flounder. © 2015 Huang et al.

Discover hidden collaborations