Duck Interleukin-22: Identification and Expression Analysis in Riemerella anatipestifer Infection

Figure 1

Molecular characterization and genetic analysis of duck IL-22 cDNA. (a) Sequences of nucleotide and deduced amino acid of duck IL-22. The underline indicated the predicted signal peptide region, black boxes indicated the conserved cysteine residues, and white box indicated the putative N-linked glycosylation area. (b) Multiple alignment of amino acid sequence of avian and mammalian IL-22. Clustal Omega software was used for multiple alignments. The identical residues among sequences were indicated with asterisks (). The underline indicated the signal peptide of duck IL-22, white boxes indicated the conserved cysteine residues between species, and the conserved IL-10 family motif is underlined using a dashed line. GenBank accession numbers used in the comparison are written after the species names. (c) Phylogenetic tree indicating the relationships between IL-22 amino acid sequences and other known IL-10 family members. The tree was made using the neighbor-joining method (MEGA version 7 program) and amino acid multiple alignments. The node values indicated percentage bootstrap confidence levels obtained from ten thousand replicates. The sequence accession numbers are written after the species name. The white box indicated duck IL-22.

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