Molecular cloning and expression of two β-defensin and two mucin genes in common carp (Cyprinus carpio L.) and their up-regulation after β-glucan feeding

In this study, we described the partial structure, mRNA tissue distribution and regulation of two carp mucin and two beta-defensin genes. This is the first description of these genes in fish. The genes might provide relevant tools to monitor feed-related improvements of fish health under aquaculture conditions. Carp mucin 2 and mucin 58 genes show a high similarity to their mammalian and avian counterparts. The carp beta-defensin 1 and beta-defensin 2 genes cluster together well with their piscine family members. The influence of a beta-glucan immunomodulant on the expression of these genes in mucosal tissues could be confirmed for the first time. Muc5B expression was significantly increased in the skin. For Muc2 no significant up- or down-regulation could be observed. Significantly higher expression levels of beta-defensin 2 in gills and both beta-defensin genes in skin were found. Thus, the mucosal system can be influenced by the addition of beta-glucans to the food. (C) 2011 Elsevier Ltd. All rights reserved.