title: A population genetic model to infer allotetraploid speciation and long-term evolution applied to two yarrow species.
abstract: Allotetraploid speciation, that is, the generation of a hybrid tetraploid species from two diploid species, and the long-term evolution of tetraploid populations and species are important in plants. We developed a population genetic model to infer population genetic parameters of tetraploid populations from data of the progenitor and descendant species. Two yarrow species, Achillea alpina-4x and A. wilsoniana-4x, arose by allotetraploidization from the diploid progenitors, A. acuminata-2x and A. asiatica-2x. Yet, the population genetic process has not been studied in detail. We applied the model to sequences of three nuclear genes in populations of the four yarrow species and compared their pattern of variability with that in four plastid regions. The plastid data indicated that the two tetraploid species probably originated from multiple independent allopolyploidization events and have accumulated many mutations since. With the nuclear data, we found a low rate of homeologous recombination or gene conversion and a reduction in diversity relative to the level of both diploid species combined. The present analysis with a novel probabilistic model suggests a genetic bottleneck during tetraploid speciation, that the two tetraploid species have a long evolutionary history, and that they have a small amount of genetic exchange between the homeologous genomes.
authors.affiliation: Ministry of Education Key Laboratory for Biodiversity Science and Ecological Engineering, and College of Life Sciences, Beijing Normal University, Beijing, 100875, China.
authors.forename: Yan-Ping
authors.initials: YP
authors.lastname: Guo
authors.affiliation: Ministry of Education Key Laboratory for Biodiversity Science and Ecological Engineering, and College of Life Sciences, Beijing Normal University, Beijing, 100875, China.
authors.forename: Xiao-Yuan
authors.initials: XY
authors.lastname: Tong
authors.affiliation: College of Life Sciences, Henan University, Kaifeng, 475001, China.
authors.forename: Lan-Wei
authors.initials: LW
authors.lastname: Wang
authors.affiliation: Institute of Animal Breeding and Genetics, University of Veterinary Medicine, A-1210, Vienna, Austria.
authors.forename: Claus
authors.initials: C
authors.lastname: Vogl
mesh_terms: D031162:Achillea / Q000235:genetics*; D000483:Alleles; D005075:Biological Evolution; D002467:Cell Nucleus / Q000235:genetics; D003198:Computer Simulation; D003600:Cytosol / Q000201:enzymology; D018742:DNA, Chloroplast / Q000235:genetics; D017343:Genes, Plant / Q000235:genetics; D049810:Genetic Speciation; D005828:Genetics, Population; D005956:Glucose-6-Phosphate Isomerase / Q000235:genetics; D006239:Haplotypes / Q000235:genetics; D008390:Markov Chains; D008957:Models, Genetic; D009010:Monte Carlo Method; D018087:Plastids / Q000235:genetics; D011110:Polymorphism, Genetic; D057891:Tetraploidy
chemical_list: D018742:DNA, Chloroplast; D005956:Glucose-6-Phosphate Isomerase