Adaptive evolution of pelvic reduction in sticklebacks by recurrent deletion of a Pitx1 enhancer

Science. 2010 Jan 15;327(5963):302-5. doi: 10.1126/science.1182213. Epub 2009 Dec 10.


The molecular mechanisms underlying major phenotypic changes that have evolved repeatedly in nature are generally unknown. Pelvic loss in different natural populations of threespine stickleback fish has occurred through regulatory mutations deleting a tissue-specific enhancer of the Pituitary homeobox transcription factor 1 (Pitx1) gene. The high prevalence of deletion mutations at Pitx1 may be influenced by inherent structural features of the locus. Although Pitx1 null mutations are lethal in laboratory animals, Pitx1 regulatory mutations show molecular signatures of positive selection in pelvic-reduced populations. These studies illustrate how major expression and morphological changes can arise from single mutational leaps in natural populations, producing new adaptive alleles via recurrent regulatory alterations in a key developmental control gene.

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

  • Alleles
  • Animals
  • Biological Evolution*
  • Chromosome Fragile Sites
  • Chromosome Mapping
  • Crosses, Genetic
  • DNA, Intergenic
  • Enhancer Elements, Genetic*
  • Fish Proteins / genetics*
  • Molecular Sequence Data
  • Mutation
  • Paired Box Transcription Factors / genetics*
  • Pelvis / anatomy & histology
  • Selection, Genetic
  • Sequence Deletion*
  • Smegmamorpha / anatomy & histology*
  • Smegmamorpha / genetics*
  • Smegmamorpha / growth & development


  • DNA, Intergenic
  • Fish Proteins
  • Paired Box Transcription Factors
  • homeobox protein PITX1

Associated data

  • GENBANK/GU130433
  • GENBANK/GU130434
  • GENBANK/GU130435
  • GENBANK/GU130436
  • GENBANK/GU130437