The genetic architecture of parallel armor plate reduction in threespine sticklebacks

PLoS Biol. 2004 May;2(5):E109. doi: 10.1371/journal.pbio.0020109. Epub 2004 Mar 30.


How many genetic changes control the evolution of new traits in natural populations? Are the same genetic changes seen in cases of parallel evolution? Despite long-standing interest in these questions, they have been difficult to address, particularly in vertebrates. We have analyzed the genetic basis of natural variation in three different aspects of the skeletal armor of threespine sticklebacks (Gasterosteus aculeatus): the pattern, number, and size of the bony lateral plates. A few chromosomal regions can account for variation in all three aspects of the lateral plates, with one major locus contributing to most of the variation in lateral plate pattern and number. Genetic mapping and allelic complementation experiments show that the same major locus is responsible for the parallel evolution of armor plate reduction in two widely separated populations. These results suggest that a small number of genetic changes can produce major skeletal alterations in natural populations and that the same major locus is used repeatedly when similar traits evolve in different locations.

Publication types

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

MeSH terms

  • Alleles
  • Animal Structures
  • Animals
  • Biological Evolution*
  • Chromosome Mapping
  • Crosses, Genetic
  • Evolution, Molecular
  • Female
  • Genetic Complementation Test
  • Genetic Variation
  • Genotype
  • Male
  • Models, Genetic
  • Molecular Sequence Data
  • Mutation
  • Phenotype
  • Quantitative Trait Loci
  • Selection, Genetic
  • Smegmamorpha / anatomy & histology*
  • Smegmamorpha / embryology*

Associated data

  • GENBANK/AY547294
  • GENBANK/BV102488
  • GENBANK/BV102489
  • GENBANK/BV102490
  • GENBANK/BV102491
  • GENBANK/BV102492
  • GENBANK/BV102493
  • GENBANK/BV102494
  • GENBANK/BV102495
  • GENBANK/BV102496
  • GENBANK/BV102497
  • GENBANK/BV102498
  • GENBANK/BV102499