title: Differential regulation drives plasticity in sex determination gene networks.
abstract: BACKGROUND
  Sex determination networks evolve rapidly and have been studied intensely across many species, particularly in insects, thus presenting good models to study the evolutionary plasticity of gene networks.
  
  
  RESULTS
  We study the evolution of an unlinked gene capable of regulating an existing diploid sex determination system. Differential gene expression determines phenotypic sex and fitness, dramatically reducing the number of assumptions of previous models. It allows us to make a quantitative evaluation of the full range of evolutionary outcomes of the system and an assessment of the likely contribution of sexual conflict to change in sex determination systems. Our results show under what conditions network mutations causing differential regulation can lead to the reshaping of sex determination networks.
  
  
  CONCLUSIONS
  The analysis demonstrates the complex relationship between mutation and outcome: the same mutation can produce many different evolved populations, while the same evolved population can be produced by many different mutations. Existing network structure alters the constraints and frequency of evolutionary changes, which include the recruitment of new regulators, changes in heterogamety, protected polymorphisms, and transitions to a new locus that controls sex determination.
authors.affiliation: CoMPLEX, University College London, UK.
authors.forename: Thomas
authors.initials: T
authors.lastname: MacCarthy
authors.forename: Robert M
authors.initials: RM
authors.lastname: Seymour
authors.forename: Andrew
authors.initials: A
authors.lastname: Pomiankowski
mesh_terms: D000818:Animals; D005075:Biological Evolution; D003198:Computer Simulation; D005260:Female; D018507:Gene Expression Regulation, Developmental; D053263:Gene Regulatory Networks; D056084:Genetic Fitness; D005838:Genotype; D008297:Male; D008957:Models, Genetic; D009154:Mutation; D011110:Polymorphism, Genetic; D019849:Sex Determination Processes / Q000235:genetics*