Resilin, the gene for the molecular spring: its roles in the flight and jumping of Drosophila

Resilin is a member of the chitin-binding protein family that was originally found as a component of an elastic matrix present in the wing hinge of insects. The matrix made of resilin (resilin matrix) is found in multiple body parts including leg joints. It has been considered that the resilin matrix may work in the absorption/relief of stresses accumulating at joints, or in the efficient transformation of muscle power to body movement. The knockdown of the gene for this protein in Drosophila melanogaster ( Resilin ) causes the characteristic downturned wing posture, and the knockdown flies cannot move their wings (and therefore they cannot fly). The jump distance of the knockdown flies is around 50% shorter than that of the controls. Null mutant flies show the same phenotypes, which can be rescued by introducing a genomic fragment harboring the whole region of Resilin . These findings indicate that Resilin plays important roles in normal wing movement and jumping. In vitro experiments have shown that the elasticity of the resilin matrix is due to the dityrosine-mediated polymerization of Resilin molecules. Dual oxidase (Duox) is the most likely candidate for the in vivo polymerization of Resilin molecules. Duox knockdown induces phenotypes similar to those observed in wing posture and jump performance of the Resilin knockdown and knockout flies, which can be rescued by the overexpression of Duox gene from a beetle. These findings suggest that Duox is an essential factor for the proper function of Resilin as the major component of the resilin matrix.