UAS regulatory sequences drive expression of vn in which the endogenous EGF domain has been replaced with a chimeric EGF domain. The chimeric EGF domain consists of the A loop of the aos EGF domain and the B and C loops of the spi EGF domain.
visible, with Scer\GAL4ptc-559.1
anterior crossvein, with Scer\GAL4ptc-559.1
72% of wings lack the anterior crossvein in flies expressing argos::spi::vnA3S.Scer\UAS under the control of Scer\GAL4ptc-559.1.