DjRlc is required for the intestinal regeneration in planarian Dugesia japonica

The myosin regulatory light chain (RLC) proteins play an important role in cellular processes, especially in muscle contraction. The planarian intestine is a fascinating system for studying the organogenesis during regeneration. In this paper, A homolog gene of Rlc, DjRlc, was identified and characterized in Dugesia japonica. The DjRlc sequence analysis revealed that it contains an opening reading frame encoding a putative protein of 175 amino acids with functionally domains that are highly conserved, including an EF-Hand motif and Ca2+ binding sites. Whole mount in situ hybridization showed that DjRlc is predominantly expressed in the intestine of intact and regenerating planarians. The cross sections of planarians revealed that the DjRlc distributes in the muscle of intact planarians. Knockdown of RNA interference of DjRlc by dsRNA-DjRlc affected the intestinal morphology, causing distinct defects in branching morphogenesis. These finding suggest that DjRlc is required for intestinal regeneration.