Genome-Wide Identification, Characterization, and Expression Analyses of the Mucin Genes in Japanese Flounder (Paralichthys olivaceus).

Mucin family members play an indispensable role in immunity against pathogen invasion. Currently, there are very few studies on members of the mucin family in Japanese flounder Paralichthys olivaceus. In this regard, we characterized the mucin members in Japanese flounder as well as their involvement in response to pathogen infection. In our results, a total of 9 mucin genes were identified based on the whole genome database of flounder. Among them, MUC2-1, MUC2-2, MUC5AC-1, MUC5AC-2 and MUC5B are secreted mucins, while MUC3A, MUC3B, MUC13 and MUC15 are membrane binding mucins. The collinearity results showed that the adjacent MUC genes of flounder had collinearity relationship with many other teleosts. Phylogenetic tree results showed that the mucin gene of flounder was divided into several subfamilies. In addition, the expression patterns of flounder mucin family members were examined in 11 healthy tissues. The expression changes of mucin gene were also detected in six immune tissues (gill, intestine, skin, liver, kidney, spleen) after pathogen infection, revealing their role in disease resistance. Collinear analysis indicates the adjacent mucin genes. According to the protein interaction network (PPI) results, the mucin genes interact with the galnt genes. The results provide a solid foundation for further research on the function of mucins in mucosal immunity of flounder. [ABSTRACT FROM AUTHOR]