Extreme changes to gene expression associated with homoploid hybrid speciation

Awduron Sefydliadau
  • Matthew Hegarty(Awdur)
  • Gary L. Barker(Awdur)
  • Adrian C. Brennan(Awdur)
  • Adrian C. Brennan(Awdur)
  • Keith J. Edwards(Awdur)
  • Richard J. Abbott(Awdur)
  • Simon J. Hiscock(Awdur)
Math Erthygl
Iaith wreiddiolSaesneg
Tudalennau (o-i)877-889
Nifer y tudalennau13
CyfnodolynMolecular Ecology
Rhif y cyfnodolyn5
Dyddiad ar-lein cynnar21 Ion 2009
Dangosyddion eitem ddigidol (DOIs)
StatwsCyhoeddwyd - Maw 2009
Cysylltiad parhaol
Gweld graff cysylltiadau
Fformatau enwi


Hybridization is an important cause of abrupt speciation. Hybrid speciation without a change in ploidy (homoploid hybrid speciation) is well-established in plants but has also been reported in animals and fungi. A notable example of recent homoploid hybrid speciation is Senecio squalidus (Oxford ragwort), which originated in the UK in the 18th Century following introduction of hybrid material from a hybrid zone between S. chrysanthemifolius and S. aethnensis on Mount Etna, Sicily. To investigate genetic divergence between these taxa, we used complementary DNA microarrays to compare patterns of floral gene expression. These analyses revealed major differences in gene expression between the parent species and wild and resynthesized S. squalidus. Comparisons of gene expression between S. aethnensis, S. chrysanthemifolius and natural S. squalidus identified genes potentially involved in local environmental adaptation. The analysis also revealed non-additive patterns of gene expression in the hybrid relative to its progenitors. These expression changes were more dramatic and widespread in resynthesized hybrids than in natural S. squalidus, suggesting that a unique expression pattern may have been fixed during the allopatric divergence of British S. squalidus. We speculate that hybridization-induced gene-expression change may provide an immediate source of novel phenotypic variation upon which selection can act to facilitate homoploid hybrid speciation in plants.