Development of diagnostic microsatellite markers from whole-genome sequences of Ammodramus sparrows for assessing admixture in a hybrid zone

Studies of hybridization and introgression and, in particular, the identification of admixed individuals in natural populations benefit from the use of diagnostic genetic markers that reliably differentiate pure species from each other and their hybrid forms. Such diagnostic markers are often infrequent in the genomes of closely related species, and genomewide data facilitate their discovery. We used whole-genome data from Illumina HiSeqS2000 sequencing of two recently diverged (600,000 years) and hybridizing, avian, sister species, the Saltmarsh (Ammodramus caudacutus) and Nelson's (A. nelsoni) Sparrow, to develop a suite of diagnostic markers for high-resolution identification of pure and admixed individuals. We compared the microsatellite repeat regions identified in the genomes of the two species and selected a subset of 37 loci that differed between the species in repeat number. We screened these loci on 12 pure individuals of each species and report on the 34 that successfully amp...