Atypical insects: molecular mechanisms of unusual life history strategies.

Metamorphosis undeniably shaped the evolutionary success of winged insects. So far, what we know about the hormonal regulation and molecular mechanisms controlling insect metamorphosis lies on the understanding of complete and incomplete metamorphosis. Rarer types of metamorphosis are overlooked, yet they could provide important insights as they represent deviations in life history strategies that are associated with unique ecological traits. The molecular mechanisms of these atypical metamorphoses are still poorly understood. With the rise of next-generation sequencing, and increasing interest in emerging organismal systems, it is now possible to start exploring the molecular mechanisms underlying atypical metamorphoses in insects. By focusing on neometaboly and paedomorphosis, we discuss how exploring their molecular mechanisms can complete our understanding on the evolution of insects and impact applied research areas. Continued decrease in next-generation sequencing costs and progress in genome editing will help decipher the proximate mechanisms of unusual life history strategies in insects.