| With the artificial breeding technology continues to improve, Litopenaeus vannameishrimp has become a species account for1/3of the total output of the world. But with theexpansion of farming scale, process of breeding for disease has brought the huge economicloss to the shrimp industry. In addition to lack of the immune disease resistant mechanism, itis difficult to solve the problem of disease control and prevention of L. vannamei in process ofcultured.Therefore, we screening differentially expressed genes of Vibrio parahaemolyticusinfected L. vannamei and normal L. vannamei by using GeneFishing technology andanalyzing the expression and distribution of these genes in normal and virus L. vannameitissues and different age stages expression patterns by quantitative real-time PCR. At the sametime, we tested the relationship between the L. vannamei body size traits and immunity wasdiscussed, the following results were obtained:1. By using29pairs of ACPs, a total of9APs showed differentially amplified PCRbands with6up-regulated bands and3down-regulated bands in intensity in the treated groupcomparing to the control group. The DEGs including L. vannamei elongation factor1-alpha(LVEF1A), L. vannamei C type Lectin-1(LvCTL-1), L. vannamei hemocyanin (Lvhc), L.vannamei glutathione peroxidase (LvGPx), clone pc-528ribosomal protein S11andS-formylglutathione hydrolase.2. The RT-PCR results showed that those genes existing in all of the tissues, specificallyor predominantly expressed in hepatopancreas. Further illustrated that hepatopancreas playsimportant role in immune mechanisms of L. vannamei. Temporal expression analysis ofLvCTL-1, Lvhc and LvGPx revealed that within4h the mRNA expressions of these geneswere increased after V. parahaemolyticus injected compares with the control group. Theidentified DEGs may play primary roles in the resistance of bacteria in L. vannamei.GeneFishing technology is a simple and efficient method for screening DEGs. Besides, theexpression of EF1A, LvCTL-1, Lvhc and LvGPx of L. vannamei in different month has greatdifferences between hepatopancreas and blood tissue. Their expression in blood is not difference with body weight. While in the hepatopancreas, the relative expression of Lvhc andLvGPx was significantly difference (P <0.01) in3-month-old and5-month-old L. vannamei.All in all, hepatopancreas and blood tissue plays different role in shrimp immune system.3. Another part of this study is to discuss the relationship of L. vannamei body size traitsand immune ability. According to different body weight and body length,3-month-old and5-month-old L. vannamei were divided into4groups,3-month-old minimum group (W1),3-month-old maximum group (W2),5-month-old minimum group (W3),5-month-oldmaximum group (W4), respectively. Extract the shrimp blood to detection the activity of AKP,ACP, CAT, LZM, GSH-PX and SOD.Research has revealed that with body weight and lengthimproving, CAT and LZM activity increased with positive correlation. However the enzymeactivity of GSH-PX with body weight increasing decreased. In addition, AKP, ACP and SODactivity show no significantly related to shrimp body length and body weight.Finally we conclude: This study screened nine differential expressed genes after Vibrioparahaemolyticus infected in L. vannamei. We choose four immune related genes to geneverification. The results illstrited that after infected4h occurring the mountain of stressresponse. In the expression of the organization, hepatopancreas showed stronger stress level,and the organ is the main immune organs of shrimp. We found that different enzyme activitiesand body size traits showed distinct correlation by detecting the shrimp body size traits andimmune related enzyme activity levels and we conclude the body size traits and immuneability have a complex relationship, not lump together. These studies accumulation of data forshrimp immune mechanism, while the micro contact body measurement traits and immunityneeds further study. |
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