Data from: Recent speciation and elevated Z-chromosome differentiation between sexually monochromatic and dichromatic species of Australian teals
Dhami, Kirandeep K., Wright State University
Joseph, Leo, Commonwealth Scientific and Industrial Research Organisation
Roshier, David A., Wright State University
Peters, Jeffrey L., Wright State University
Published Aug 04, 2015 on Dryad.
Cite this dataset
Dhami, Kirandeep K.; Joseph, Leo; Roshier, David A.; Peters, Jeffrey L. (2015). Data from: Recent speciation and elevated Z-chromosome differentiation between sexually monochromatic and dichromatic species of Australian teals [Dataset]. Dryad. https://doi.org/10.5061/dryad.p0p92
Sex chromosomes potentially have an important role in speciation and often have elevated differentiation between closely related species. In birds, traits associated with male plumage, female mate preference, and hybrid fitness have been linked to the Z-chromosome (females are heterogametic, ZW). We tested for elevated Z-differentiation between two recently diverged species of Australian ducks, the sexually monochromatic grey teal Anas gracilis and the dichromatic chestnut teal A. castanea. Despite prominent morphological differences, these two species are genetically indistinguishable at both mitochondrial DNA (mean ΦST < 0.0001) and 17 autosomal loci (mean ΦST = 0.0056). However, we detected elevated Z-differentiation (mean ΦST = 0.281) and tentative evidence of an island of differentiation on the Z-chromosome. This elevated differentiation was explained by a high frequency of derived alleles in chestnut teal that were absent in grey teal, which parallels independent evidence for a gain in dichromatism from a monochromatic ancestor. Coalescent estimates of demographic history and simulations indicated that the elevated Z-differentiation was unlikely to be explained by neutral processes, but instead supported a role of divergent selection. We discuss evidence for models of speciation with gene flow versus adaptive divergence in the absence of gene flow and find that both hypotheses are plausible explanations of the data. Overall, these teal have the weakest background differentiation documented to date for a species showing a large Z-effect, and they are an excellent model species for studying speciation genomics and the evolution of sexual dichromatism.
Specimen data for Australian Teal
Specimen information for 23 Chestnut teal (Anas castanea) and 48 grey teal (Anas gracilis), including specimen number, DNA number, sex, and collection locality.
Phased FASTA files
FASTA files for phased alleles from 7 Z-chromosome introns and 17 autosomal introns sequenced from chestnut teal and grey teal.
Concatenated NEXUS files
NEXUS files of concatenated DNA sequences for 7 Z-chromosome loci (69 individuals; 2637 bp) and 17 autosomal loci (71 individuals; 5351 bp). Each individual is represented by a single consensus sequence with polymorphic positions coded by IUPAC ambiguity codes. Missing data are coded as "?".
IMa2 input files
IMa2 input files for 7 Z-chromosome loci and 17 autosomal loci. Sequences are partitioned into two populations "CT" for chestnut teal and "GT" for grey teal. Sequences have been filtered to be consistent with no recombination.