Myoinhibiting peptides are the ancestral ligands of the promiscuous Drosophila sex peptide receptor448, Poels, J, Van Loy T., Vandersmissen H.P., Van Hiel B., Van Soest S., Nachman R.J., and J. Broeck Vanden , Cell Mol.Life Sci., 0/10/2010, Volume 67, Issue 20, Number 3522, p.3511 - 3522, (2010)