The Toxic Effect Of Microcystis On Litopenaeus Vannamei Immune Cell Gene Expression Level

Microcystin (MCs) is a blue-green algae blooms most common form of algal toxin,often in the hot season occurs in freshwater lakes and ponds, the water of life in aquaticorganisms caused great impact on aquaculture caused great harm. Microcystin toxin is aliver toxin, the main target organ is the liver of animals. Studies have shown that invannamei pond, formed the dominant species Microcystis aeruginosa and shrimpdisease outbreaks were positively correlated, shrimp pond showing the incidence ofdiatoms to cyanobacteria advantage succession. In production, aquaculture ponds late,the outbreak of blue-green algae blooms are often led shrimp unexplained death.Exposure to certain concentrations of Microcystis aeruginosa Procambarus shrimpvannamei and giant freshwater prawn juvenile survival rate was significantly lower,andthe shrimp’s Color and ultrastructural change significantly.Vannamei is one of three varieties of the world’s highest production in farmedshrimp(Monodon P. monodon, L. vannamei shrimp L. vannamei and China F.chinensis).It has a mixed diet, fast growth, fecundity, high survival rate, easy feeding andnutritional advantages, so loved by the farmers and consumers. However, due to theoutbreak of disease hazards shrimp farming it faces a high risk of farming. Even afterscientists,the government and enterprises tireless efforts to restore a certain amount ofaquaculture production, reducing the risk of breeding, but the epidemic is still hangingshrimp farmers in the heart of the sword. Therefore, carry out related research vannameiimmune defense mechanisms, prevention and treatment of immune explore new ways toachieve their health and disease control breeding have great significance.In this paper, research status at home and abroad, the immune defense mechanisms ofcrustaceans were reviewed, analyzed the immune mechanisms and immune-relatedgenes and proteins crustaceans such as cell-mediated immunity and humoral immunityprocess. Through vannamei injected by microcystin MC-LR exposure, access to thepancreas and liver tissue samples of blood, using Illumina Hiseq2500sequencingvannamei obtained before and after the injection of the blood and microcystinhepatopancreas transcriptome. Explore the mechanism of toxicity of microcystin shrimpfrom the liver and blood lymphocyte immune toxic effects. And the use of flow cytometry detect cell apoptosis in shrimp Litopenaeus after injection of microcystin.And using confocal observation verified the occurrence of apoptosis. The results wereas follows: In the blood and liver samples were found have significantly different genesequence expression, including through blood samples to determine the platelet-reactiveprotein (thrombospondin) and cyclin B (cyclin B) two genes, liver pancreas samples todetermine prophenoloxidase (prophenoloxidase), trypsin (trypsin) and C-type lectin(C-type lectin) and other10kinds of genes. No obvious areas of cellular immunity genetranscription occurs in a significant expression differences in the results appear,prophenoloxidase and C-type lectin belong to the scope of humoral immunity, but theshrimp immune system cells and humoral immune interaction itself, inseparable.(2)GO significantly different results confirmed the expression of cell adhesion,cell killingand cell adhesion molecule binding other immune-related gene expression in blood cells.In hepatopancreas sample group found no significant cellular immune related GOsignificantly differentially expressed, but it is worth mentioning that many of themoxidoreductase and GO significantly differentially expressed protein metabolism related.KEGG PATHWAY significant differences in the expression of results showed that thehepatopancreas and blood sample groups are present phagosome (Phagosome),apoptosis (Apoptosis), endocytosis (Endocytosis) and cell adhesion molecules (Celladhesion molecules (CAMs)) and other channels.(3)After trypan blue staining ofvannamei blood cells, count the cells number in various time periods, and calculate celldeath. The number of shrimp Litopenaeus blood cells:3.9×106-4.5×106cell/ml.3h,12h,24h,48h each cell mortality statistics:25.0%,37.5%,66.7%and73.3%.(4)Theresult of PI staining flow cytometry detect the hepatopancreas cells of vannamei whichinjected by Microcystis showed have obvious apoptosis been occurred. Theexperimental results confirmed in the case of microcystin-infected shrimp Litopenaeusapoptosis phenomenon exists, and there is a certain relationship with the injection time.(5) laser confocal cell apoptosis results also proved that after microcystin vannameiinfected liver cell apoptosis in hepatopancreas really happened.These results suggest that L. vannamei infected microcystin toxin variety ofimmune-related genes have undergone significant differential expression, confirmed thephagocytosis and cell apoptosis in immune response against infection microcystin playto an important role. Flow cytometry and confocal microscopy observations alsoconfirmed a significant phenomenon in shrimp cell apoptosis, and there is a certainrelationship between the time of infection.