Data from: Unidirectional diploid–tetraploid introgression among British birch trees with shifting ranges shown by restriction site-associated markers ...

• Main Authors: Zohren, Jasmin, Wang, Nian, Kardailsky, Igor, Borrell, James S., Joecker, Anika, Nichols, Richard A., Buggs, Richard J. A.
• Format: Dataset
• Language: English
• Published: Dryad 2016
• Subjects: mapping; Betula pubescens; R object; FST; reference sequence; Betula nana; Betula pendula; Dwarf birch
• Online Access: https://dx.doi.org/10.5061/dryad.815rj; https://datadryad.org/stash/dataset/doi:10.5061/dryad.815rj

Hybridization may lead to introgression of genes among species. Introgression may be bidirectional or unidirectional, depending on factors such as the demography of the hybridizing species, or the nature of reproductive barriers between them. Previous microsatellite studies suggested bidirectional introgression between diploid Betula nana (dwarf birch) and tetraploid B. pubescens (downy birch) and also between B. pubescens and diploid B. pendula (silver birch) in Britain. Here, we analyse introgression among these species using 51 237 variants in restriction site-associated (RAD) markers in 194 individuals, called with allele dosages in the tetraploids. In contrast to the microsatellite study, we found unidirectional introgression into B. pubescens from both of the diploid species. This pattern fits better with the expected nature of the reproductive barrier between diploids and tetraploids. As in the microsatellite study, introgression into B. pubescens showed clear clines with increasing introgression from ... : Genotyping method (mixed ploidy dataset)This script allows the genotyping of a mixed ploidy data set (including polyploids). It is based on read counts and average base quality. The algorithm calculates the most likely variant configuration at each locus using a log-likelihood model.genotyping.RBeta-binomial model for allelic ratiosFunction to model number of reads per SNP allele as a mixture of beta-binomial distributions. The data are censored to be between two cutoff values.betabinomial.RPlotting of figuresCollection of scripts used for plotting figures in the present study.plotting.RAnalyses used in present studyCollection of scripts used for analyses in the present study.analyses.RBetula RAD reference sequenceThese sequences were concatenated and used as a reference for the mapping of the 213 RAD individuals.Betula_RAD_reference.fasta.gzInput file for STRUCTURE analysisThis file was used to analyse the RAD data in STRUCTURE. The first row contains loci names, the first column individual names, the ...