Oncogenic cooperation between Yorkie and the conserved microRNA in the wing disc of .

Tissue growth has to be carefully controlled to generate well-functioning organs. MicroRNAs are small non-coding RNAs that modulate the activity of target genes and play a pivotal role in animal development. Understanding the functions of microRNAs in development requires the identification of their target genes. Here, we find that , a conserved microRNA in the family, controls tissue growth and homeostasis in the wing imaginal disc. Upregulation of causes the repression of , the effector of the Hippo pathway in , and reduces tissue size. Remarkably, co-expression of and causes the formation of neoplastic tumors. We show that upregulation of represses the growth inhibitor , and depletion of cooperates with in the formation of neoplastic tumors. Hence, modulates a positive growth regulator, , and a negative growth regulator, Deregulation of this network can result in the loss of tissue homeostasis and the formation of tumors.