Insulin signalling underlies both plasticity and divergence of a reproductive trait in Drosophila

Proc Biol Sci. 2014 Feb 5;281(1779):20132673. doi: 10.1098/rspb.2013.2673. Print 2014 Mar 22.

Abstract

Phenotypic plasticity is the ability of a single genotype to yield distinct phenotypes in different environments. The molecular mechanisms linking phenotypic plasticity to the evolution of heritable diversification, however, are largely unknown. Here, we show that insulin/insulin-like growth factor signalling (IIS) underlies both phenotypic plasticity and evolutionary diversification of ovariole number, a quantitative reproductive trait, in Drosophila. IIS activity levels and sensitivity have diverged between species, leading to both species-specific ovariole number and species-specific nutritional plasticity in ovariole number. Plastic range of ovariole number correlates with ecological niche, suggesting that the degree of nutritional plasticity may be an adaptive trait. This demonstrates that a plastic response conserved across animals can underlie the evolution of morphological diversity, underscoring the potential pervasiveness of plasticity as an evolutionary mechanism.

Keywords: Drosophila erecta; Drosophila sechellia; insulin receptor; ovariole; ovary; phenotypic plasticity.

Publication types

  • Research Support, N.I.H., Extramural
  • Research Support, Non-U.S. Gov't
  • Research Support, U.S. Gov't, Non-P.H.S.

MeSH terms

  • Animals
  • Drosophila / genetics
  • Drosophila / metabolism
  • Drosophila / physiology*
  • Female
  • Fertility
  • Genotype
  • Insulin / metabolism*
  • Ovary / anatomy & histology
  • Ovary / growth & development
  • Ovary / physiology
  • Phenotype
  • Signal Transduction*
  • Somatomedins / metabolism

Substances

  • Insulin
  • Somatomedins