RNAi of CNS-expressed gene DjS']jSlk induces morphogenetic malformation and death in planarian Dugesia japonica

Ste20-like kinases are critically multifuctional proteins which play important roles in varieties of celluar processes and physiological events. Here, We characterized a Ste20-like kinase gene (DjSlk) in planarian Dugesia japonica. Whole-mount in situ hybridizations revealed that DjSlk was expressed in the central nervous system (CNS) including cephalic ganglia and ventral nerve cords (VNCs) in intact and regenerating animals. After RNA interference (RNAi) of DjSlk, adult planarians became immobilized and wrinkled, then swelled and lysed eventually. DjSlk RNAi treated regenerating planarians could form the entire animals, and then displayed the similar phenotype transformation. These results suggest that loss of function of DjSlk leads to morphogenetic malformation of planarian D. japonica probably via regulating cell volume instead of disrupting the balance between cell proliferation and apoptosis.