Project description:Cultured shrimp are continuously exposed to variable environmental conditions which are associated with stress and subsequent outbreaks of disease. To investigate the effect of environmental stress on Penaeus monodon gene expression, a 3853 random cDNA microarray chip was generated with clones originating from 6 stress-enriched hemocyte libraries generated by suppression subtractive hybridization and a normal hemocyte cDNA library. Changes in temporal gene expression were analyzed from shrimp exposed to hypoxic, hyperthermic and hypoosmotic conditions. 3.1% of the cDNAs were differentially expressed in response to at least one of the environmental stressors. 70% of the differentially expressed clones had no significant sequence similarity to previously known genes. Among those genes with high identity to known sequences, the most common functional groups were immune related genes and non-LTR retrotransposons. Hierarchical clustering revealed a set of cDNAs with temporal and stressspecific gene expression profiles as well as a set of cDNAs indicating a common stress response between stressors. Hypoxic and hyperthermic stressors induced the most severe short-term response in terms of gene regulation, and the osmotic stress had the least variation in expression profiles relative to the control. These expression data agree with observed differences in shrimp physical appearance and behavior following exposure to stress conditions. Keywords: stress response, shrimp, time series
Project description:Yellow head virus (YHV) is one of the most serious pathogens that causes worldwide shrimp production loss. It enters the cells via clathrin-mediated endocytosis and utilizes small GTPase Rab proteins such as PmRab5 and PmRab7 for intracellular trafficking. In this study, molecular cloning and functional analysis of Rab11 during YHV infection were investigated. PmRab11 cDNA was cloned by Rapid amplification of cDNA ends (RACEs). It contained two forms of sizes 1200 and 1050 bp distinct at the 5' UTR. The coding region of PmRab11 was 645 bp, encoding 214 amino acids. It also demonstrated the characteristics of Rab11 proteins containing five GTP-binding domains, five Rab family domains, four Rab subfamily domains and a prenylation site at the C-terminus. Suppression of PmRab11 using dsRNA-PmRab11 either before or after YHV-challenge resulted in significant inhibition of YHV levels in the hemocytes and viral release in the supernatant in both mRNA and protein levels. In addition, the silencing effect of PmRab11 in YHV-infected shrimps resulted in a delay in shrimp mortality for at least 2 days. Immunofluorescence study showed co-localization between PmRab11 and YHV at 24-72 h post YHV-challenge. In contrast, the co-localization signals were absence in the PmRab11 knockdown hemocytes and the YHV signals accumulated at the perinuclear region at 24 h post YHV-challenge. Then, accumulation of YHV was hardly observed after 48-72 h. These results suggested that PmRab11 is required for YHV infection in shrimp.
Project description:A virus with a circular Rep-encoding single-stranded DNA (ssDNA) (CRESS-DNA) genome (PmCV-1) was isolated from Penaeus monodon shrimps in Vietnam. The gene structure of the 1,777-nucleotide (nt) genome was similar to that of circoviruses and cycloviruses, but the nucleic acid and protein sequence identities to these viruses were very low.
Project description:High-resolution skim-sequencing based genotyping of wild and domesticated population of giant tiger shrimp (Penaeus monodon) in Indo-Pacific region