miR-184 modulates dilp8 to control developmental timing during normal growth conditions and in response to developmental perturbations

Organismal development depends on the precise coordination of growth and developmental timing, which is regulated by a complex interplay of intrinsic and extrinsic factors. However, the mechanisms underlying this regulation are not fully understood. Post-transcriptional regulation by microRNAs (miRNAs) plays a pivotal role in ensuring the proper timing of gene expression necessary for growth and development. In this study, we conducted a genetic screen to identify microRNAs that regulate developmental timing inDrosophila. Our screen identifiedmiR-184,previously implicated in germline maturation and embryonic development, as a regulator of pupariation timing by acting in the larval imaginal discs. Using genetic and molecular approaches, we identifiedDrosophila insulin-like peptide 8(Dilp8), a paracrine factor critical for regulating developmental stability, as a target ofmiR-184. During normal larval development miR-184 facilitates timely pupariation by regulatingdilp8levels. Furthermore, we demonstrate that miR-184 plays a critical role in tissue damage responses by inducingdilp8expression, which delays pupariation to enable damage repair mechanisms. These findings reveal a novel post-transcriptional regulatory mechanism that links miR-184 to the control of developmental timing under normal growth conditions and in response to tissue damage.