Dinucleotide repeat polymorphisms in waterfowl (family Anatidae): Characterization of a sex-linked (Z-specific) and 14 autosomal loci

Canada goose (Branta Canadensis) and harlequin duck (Histrionicus histrionicus) DNAs were digested with Sau3AI, and size selected (300-700 bp) fragments were ligated into BamHI-digested pBluscriptII KS⁺. The enrichment protocol of Ostrander et al.¹ was followed. The resulting libraries were screened using a [ƴ-³²P]ATP end-labelled (CA)₂₀ oligonucleotides as a hybridization probe. Positive clones were sequenced using cycle-sequencing protocols (Epicentre Technologies, Madison, WI) and primers flanking the inserts. PCR primers were designed to amplify the repeat and yield amplification products of ≈100-200 bp. DNA  samples were screened for variation at these loci using [ƴ-³²P]ATP end-labelled primers. The products were resolved using 6% denaturing polyacrylamide gels and autoradiography.