Nemo phosphorylates Eyes absent and enhances output from the Eya-Sine oculis transcriptional complex during Drosophila retinal determination

► Nemo positively regulates Eya to promote Drosophila retinal determination. ► Nemo promotes expression of the Eya-So transcriptional targets dac and lozenge. ► Two consensus MAPK phosphorylation sites on Eya are phosphorylated by Nemo. ► Nemo phosphorylation of Eya is required for promotion of Eya-So activity in vivo.