Expression Analysis of Lily Type Lectin Isotypes in the Rock Bream, Oplegnathus fasciatus: in the Tissue, Developmental Stage and Viral Infection

Abstract

Lectins belong to the pattern-recognition receptors (PRRs) class and play important roles in the recognition and elimination of pathogens via the innate immune system. Recently, it was reported that lily-type lectin-1 is involved when a pathogen attacks in the early immune response of fish. However, this study is limited to information that the lectin is involved in the innate immune response against viral infection. In the present study, the lily-type lectin-2 and -3 of Oplegnathus fasciatus (OfLTL-2 and 3) have been presented to be included B-lectin domain and two D-mannose binding sites in the amino acid sequence that an important feature for the fundamental structure. To investigate the functional properties of OfLTLs, the tissue distribution in the healthy rock bream and temporal expression during early developmental stage analysis are performed using quantitative real-time PCR. OfLTL-2 and 3 are predominantly expressed in the liver and skin, but rarely expressed in other organ. Also, the transcripts of OfLTLs are not expressed during the early developmental stage but its transcripts are increased after immune-related organs which are fully formed. In the challenge experiment with RBIV (rock bream iridovirus), the expression of OfLTLs was increased much more strongly in the late response than the early, unlike previously known. These results suggest that OfLTLs are specifically expressed in the immune-related tissues when those organs are fully formed and it can be inferred that the more intensively involved in the second half to the virus infection.

Expression Analysis of Interferon-Stimulated Gene 15 in the Rock Bream Oplegnathus fasciatus against Rock Bream Iridovirus (RSIV) Challenge

“…Adults inhabit coastal rocky reefs, while juveniles associate with drifting seaweed and feed on zooplankton. It is an economically important resource in the fishing industry in Korea ( Oh et al, 2007 ; Lee et al, 2016 ). Due to the rapid development of the aquaculture industry in recent years, the spread of bacterial and viral diseases has resulted in economic losses, including massive losses and reductions in productivity ( Jung & Oh, 2000 ; Lee et al, 2016 ).…”

“…The generation of antibodies against a particular pathogen takes a day or several days ( Medzhitov & Janeway, 1997 ; Magnadottir et al, 2006 ). Moreover, because there is a delay before the initial adaptive immune response takes effect, the innate immune response plays a critical role in the control of infections during this period ( Lee et al, 2016 ).…”