Keeping an Eye on Plasticity Genes: Insulin/TOR Pathway Components Mediating Nutritional Plasticity of Eyes Within and Between Sex

Perturbing Insulin/TOR pathway nodes in Drosophila melanogaster modulates how starvation-driven nutritional variation scales eye size, with effects that are sex-dependent.

• Why it matters: Nutrient-dependent eye sizing and allometry within and between sexes are poorly understood, despite known gene networks for eye patterning and growth.
• What they did: A screen of the Insulin/TOR pathway showed pathway perturbations alter nutritional effects on eye size and scaling; RNAi knockdown of each component in an eye-specific manner quantified impacts on mean, slope, intercept, variance, and sex-limited plasticity.
• The result: Starvation reduced eye size and body size proportionately in females but changed eye-to-body size disproportionately in males, and pathway components ranged from shutting off plasticity to amplifying it, implying morphospace evolution via plasticity genes.