Abstract:Bantam is a type of miRNA involved in cell proliferation and apoptosis, and can affect immune processes in animals. In the present study, bantam expression in the hepatopancreas and gill of WSSV-infected Chinese shrimp Fenneropenaeus chinensis was determined using the qRT-PCR technique. The results showed that bantam expression in the hepatopancreas of Chinese shrimp 6, 12, 24, and 48 h post infection was (0.16±0.03)(P<0.05), (0.63±0.26), (0.32±0.06) (P<0.05), and (0.41±0.13) fold that of the expression in the controls, respectively. Bantam expression in the gill of Chinese shrimp 6, 12, 24, and 48 h post infection was (0.30±0.17) (P<0.05), (1.88±0.26) (P<0.01), (0.84±0.36), and (0.51±0.25) fold that of the expression in the controls, respectively. The target genes of bantam were predicted using the miRanda software. The ubiquitin-conjugating enzyme E2 was the predicted target gene with the highest score. The Chinese shrimp ubiquitin-conjugating enzyme E2 contains the ubiquitin-conjugating enzyme E2, catalytic (UBCc) domain. Multiple alignment results showed that the UBCc domain was relatively conserved among different species. Phylogenetic analysis showed that the ubiquitin-conjugating enzyme E2 in species with closer taxonomic status was clustered in a branch. Pair-wise and multiple sequence alignment revealed that the ubiquitin-conjugating enzyme E2 was relatively well-conserved. Ubiquitin- conjugating enzyme E2 expression in the hepatopancreas and gill of WSSV-infected Chinese shrimp was further determined using qRT-PCR. The results showed that the expression of ubiquitin-conjugating enzyme E2 in the hepatopancreas of Chinese shrimp 6, 12, 24, and 48 h post-WSSV infection was (0.54±0.10), (1.19±0.62), (3.69±0.51)(P<0.01), and (1.94±0.07)(P<0.05) fold that of the expression in the controls, respectively. The expression of ubiquitin-conjugating enzyme E2 in the gill of Chinese shrimp 6, 12, 24 and 48 h post WSSV infection was (0.22±0.05), (1.34±0.38), (4.29±0.52) (P<0.01), and (1.28±0.79) fold that of the expression in the controls. These results suggest that both bantam and the target gene ubiquitin-conjugating enzyme E2 might be involved in the interaction between Chinese shrimp and WSSV. Whether the altered expression of bantam and ubiquitin-conjugating enzyme E2 represents the immune response of shrimps to WSSV infection, or the hijacking of cells by WSSV during the viral infection process, needs further study.
