Invasion of diverse habitats by few Japanese knotweed genotypes is correlated with epigenetic differentiation.
The expansion of invasive species challenges our understanding of the process of adaptation. Given that the invasion process often entails population bottlenecks, it is surprising that many invasives appear to thrive even with low levels of sequence-based genetic variation. Using Amplified Fragment Length Polymorphism (AFLP) and methylation sensitive-AFLP (MS-AFLP) markers, we tested the hypothesis that differentiation of invasive Japanese knotweed in response to new habitats is more correlated with epigenetic variation than DNA sequence variation. We found that the relatively little genetic variation present was differentiated among species, with less differentiation among sites within species. In contrast, we found a great deal of epigenetic differentiation among sites within each species and evidence that some epigenetic loci may respond to local microhabitat conditions. Our findings indicate that epigenetic effects could contribute to phenotypic variation in genetically depauperate invasive populations. Deciphering whether differences in methylation patterns are the cause or effect of habitat differentiation will require manipulative studies.
Department of Integrative Biology, University of South Florida, Tampa, FL 33617, USA. clr@usf.edu
Christina L
CL
Richards
Aaron W
AW
Schrey
Massimo
M
Pigliucci
D054458:Amplified Fragment Length Polymorphism Analysis; D017753:Ecosystem; D044127:Epigenesis, Genetic; D045468:Fallopia japonica / Q000235:genetics* / Q000254:growth & development; D014644:Genetic Variation; D005838:Genotype; D058865:Introduced Species; D010641:Phenotype; D011157:Population Dynamics