Effect of WSSV-Infection on Relative Expression of Hemocyanin Genes in Litopenaeus Vannamei (Boone, 1931)

Abstract

A Litopenaeus vannamei injected with the serum from the shrimps infected with WSSV-showed the typical symptoms of white spot syndrome at 48hpi. These include lethargy, lack of appetite, reduced and disoriented swimming activity. The negative control and serum from healthy shrimps did not show any band and the test samples contained a band corresponding to 310 bp which was like that of the positive control. Thus, the test samples were confirmed positive for the WSSV-infection. The mean serum protein concentration in healthy shrimp was 86.4 ± 6.3 mg/ml. on the other hand the serum protein concentration of WSSV-injected shrimps declined linearly and significantly to 58.8 ± 3.9, 46.2 ± 5.32, and 38.7 ± 6.7 mg/ml at 12, 24, and 48 hpi, respectively. Relative quantity of hemocyanin gene (I) expression in WSSV-injected shrimps increased gradually from 6 to 48 hpi. Analyses of relative quantification of hemocyanin gene (II) in the experimental groups showed that the relative quantity in WSSV- injected shrimps increased from 6 hpi up to 24 hpi, whereas at 48 hpi the WSSV-injected shrimps showed a decrease in relative quantity of hemocyanin gene (II). Analyses of relative quantification of hemocyanin gene (III) in the experimental groups showed that the relative quantity in WSSV-injected shrimps increased slowly from 6 to 12 hpi and the increase was found to be high at 24 and 48 hpi. The relative quantity increased in sham-injected shrimps. The melt curve analysis showed two peaks corresponding to 18S rRNA and hemocyanin gene I, II and III, respectively. The objective of the present study was directed towards the relative quantification of the hemocyanin genes (I, II and III) in L. vannamei upon WSSV-infection.