The Role of MicroRNAs in Drosophila Regulation of Insulin-Like Peptides and Ecdysteroid Signalling: Where Are We Now?

Arthropods are the most successful group of terrestrial animals in terms of their diverse habitats and species numbers. Understanding their evolution has conventionally been linked to comparison of their developmental modes and morphologies. Within the field of evolutionary developmental biology, the actions of hormones are usually ignored as hormones are thought to function more as regulators of metabolic activity associated with late developmental stages, such as ecdysis and metamorphosis. In recent years, the field of evolutionary endocrinology has emerged with the advances in sequencing techniques. Here, we consolidate the current findings of microRNA actions on insulin-like peptides and ecdysteroids in the major insect genetic model, Drosophila melanogaster. MicroRNA regulation of hormone activity remains a neglected area that needs to be developed using other insect and arthropod models to understand the diverse adaptations exhibited by this most successful group of animals.