Nonmuscular Troponin-I is required for gastrulation in sea urchin embryos.

These results strongly suggested that TnI regulates nonmuscular actin-myosin interactions during sea urchin gastrulation. So far, Troponin system is treated as specific only for muscle components, especially for striated muscle, but our data clearly show that TnI is involved in nonmuscular event. It is also reported that recent sensitive gene expression analysis revealed that Troponin genes are expressed in nonmuscular tissues in mammals (Ono et al., Sci Data, 2017;4:170105). These evidences propose the new evolutionary and functional scenario of the involvement of Troponin system in nonmuscular cell behaviors using actin-myosin system in bilaterians including human being.