# miR-184 modulates Ilp8 to control developmental timing during normal growth conditions and in response to developmental perturbations

## TL;DR

The study shows that miR-184 controls developmental timing in fruit flies by regulating a hormone called Ilp8, both during normal growth and after tissue damage.

## Contribution

miR-184 is newly identified as a post-transcriptional regulator of Ilp8, influencing developmental timing in Drosophila.

## Key findings

- miR-184 regulates Ilp8 levels to ensure timely pupariation during normal larval development.
- miR-184 aids in Ilp8 induction following tissue damage, delaying pupariation.
- This reveals a novel post-transcriptional mechanism linking miR-184 to developmental timing.

## Abstract

Organismal development depends on the precise coordination of growth and developmental timing, which is regulated by a complex interplay of factors. However, the mechanisms underlying this regulation are not fully understood. Post-transcriptional regulation by microRNAs plays a pivotal role in ensuring the proper timing of gene expression during growth and development. Here, we conducted a genetic screen to identify microRNAs that regulate developmental timing in Drosophila. Our screen identified miR-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 identified Drosophila Insulin-like peptide 8 (Dilp8; Ilp8), a secreted factor that is crucial for regulating developmental stability, as a target of miR-184. During normal larval development, miR-184 facilitates timely pupariation by regulating Ilp8 levels. Furthermore, we demonstrate that miR-184 plays an essential role in tissue damage responses by aiding in the induction of Ilp8 expression, which delays pupariation. These findings reveal a previously unreported post-transcriptional regulatory mechanism that links miR-184 to the control of developmental timing under normal growth conditions and in response to tissue damage.

Summary: miR-184 modulates insulin-like peptide 8 to coordinate developmental timing in Drosophila under normal conditions and following tissue damage.