| In all animals, heart development is regulated by a complex evolutionarily conserved genetic network involving T-box transcription factors. In Drosophila melanogaster, the two closely related genes H15 and midline are homologous to vertebrate Tbx20 genes, which encode T-box transcription factors required for proper heart development. H15 and midline are required for heart morphogenesis, and can induce ectopic heart cells when ectopically expressed in the mesoderm. Here, I show that H15 and midline are expressed in all cardioblasts, the contractile cells of the fly heart, midline expression in cardioblasts is regulated by the GATA Zn-finger transcription factor pannier, Notch signaling and the Egfr signaling pathway. Lastly, I provide genetic evidence that midline cooperates with other cardiogenic transcription factors in promoting heart cell fates. |
