Brk regulates wing disc growth in part via repression of Myc expression

The molecular mechanisms regulating tissue size represent an unsolved puzzle in developmental biology. One signalling pathway controlling growth of the Drosophila wing is Dpp. Dpp promotes growth by repression of the transcription factor Brk. The transcriptional targets of Brk that control cell growth and proliferation, however, are not yet fully elucidated. We report here a genome-wide ChIP-Seq of endogenous Brk from wing imaginal discs. We identify the growth regulator Myc as a target of Brk and show that repression of Myc and of the miRNA bantam explains a significant fraction of the growth inhibition caused by Brk. This work sheds light on the effector mechanisms by which Dpp signalling controls tissue growth.