Together with Abl, involved in embryonic neural development. May have a role in eye development. Acts as an adapter protein for SH2-domain containing proteins during sevenless (sev) signaling. Binds the SH3 domains of drk via the Pro-rich domain. When phosphorylated, can interact with the SH2 domains of drk. Binds sev via the phosphotyrosine interaction domain (PID). Uniformly expressed in the embryo from blastoderm through gastrulation. Highly expressed in the mesoderm and CNS during germ-band retraction. CNS expression is later localized to axon bundles. Detected in the embryonic PNS and body wall muscles. Expressed in the eye at the morphogenetic furrow and in developing photoreceptor cells posterior to the furrow. Embryonic axonogenesis. Probably phosphorylated by the Abl tyrosine kinase. Phosphorylated on tyrosine residues in response to sevenless activation. Intron retention.