RT Journal Article
SR Electronic
T1 Conserved DNA polymorphisms distinguish species in the eastern North American white oak syngameon: Insights from an 80-SNP oak DNA genotyping toolkit
JF bioRxiv
FD Cold Spring Harbor Laboratory
SP 602573
DO 10.1101/602573
A1 Andrew L. Hipp
A1 Alan T. Whittemore
A1 Mira Garner
A1 Marlene Hahn
A1 Elisabeth Fitzek
A1 Erwan Guichoux
A1 Jeannine Cavender-Bares
A1 Paul F. Gugger
A1 Paul S. Manos
A1 Ian S. Pearse
A1 Charles H. Cannon
YR 2019
UL http://biorxiv.org/content/early/2019/04/09/602573.abstract
AB The eastern North American white oaks, a complex of approximately 16 potentially interbreeding species, have become a classic model for studying the genetic nature of species in a syngameon. Genetic work over the past two decades has demonstrated the reality of oak species, but gene flow between sympatric oaks raises the question of whether there are conserved regions of the genome that define oak species. Does gene flow homogenize the entire genome? Do the regions of the genome that distinguish a species in one part of its range differ from the regions that distinguish it in other parts of its range, where it grows in sympatry with different species? Or are there regions of the genome that are relatively conserved across species ranges? In this study, we revisit seven species of the eastern North American white oak syngameon using a set of 80 SNPs selected in a previous study because they show differences among, and consistency within, the species. We test the hypothesis that there exist segments of the genome that do not become homogenized by repeated introgression, but retain distinct alleles characteristic for each species. We undertake a rangewide sampling to investigate whether SNPs that appeared to be fixed based on a relatively small sample in our previous work are fixed or nearly fixed across the range of the species, Each of the seven species remains genetically distinct across its range, given our diagnostic set of markers, with relatively few individuals exhibiting admixture of multiple species. This application of a DNA barcode designed for the simple problem of identifying speices in the field has an important implication: the eastern North American white oak syngameon is composed of entities that most taxonomists would consider “good species,” and species in the syngameon retain their genetic cohesion because characteristic portions of the genome do not become homogenized despite a history of introgression.