Identification and functional characterization of Wts from kuruma Shrimp ( <i>Penaeus japonicus</i> ) in response to <i>Vibrio harveyi</i> challenge

As a key member in Hippo signal pathway, Wts plays an important role in animal growth and immunity. To investigate the role of Wts in innate immunity of kuruma shrimp Penaeus japonicus , the cDNA and genome sequence of Wts from P. japonicus (designated as PjWts) were isolated and characterized. The PjWts cDNA was 4,123 bp length, including an open reading frame of (ORF) 3,438 bp encoding 1,145 amino acids. No transmembrane structure or signal peptide was found in PjWts. The predicted protein contains a MobB domain and a STKc_LATS domain. The result of multiple alignment showed that these domains were highly conserved across different species. The genomic sequence of PjWts consists 7 exons and 6 introns. PjWts was expressed in all tested tissues, with high expression level in ganglia, gill, ovary and lymph. After Vibrio harveyi was injected, the expression of PjWts in the gill and hepatopancreas were significantly upregulated at 3h. After PjWts silencing, the expression of PjWts in hepatopancreas and gill were gradually decreased. The mortality rate of P. japonicus co-injected with dsRNA-Wts and V. harveyi was significantly higher than that of other groups. All of these results suggest that PjWts may be involved in the innate immunity of P. japonicus . This study provides a useful foundation for elucidating the function of Wts in P. japonicus innate immunity.