Polymerase-chain-reaction (pcr) Analysis of Microsatellites--a New Approach to Studies of Genetic Relationships in Birds

A13STRACT.--Genomic DNA libraries of the Barn Swallow (Hirundo rustica) and the Pied Flycatcher (Ficedula hypoleuca) were screened for the presence of dinucleotide microsatellite repeats. Two thymine-guanine repeats, "(TG),," and two thymine-cytosine repeats, "(TC),," were isolated and sequenced from the two species, respectively. Polymerase-chain-reaction (PCR) analysis of 25 unrelated Barn Swallows and 10 unrelated Pied Flycatchers revealed 3 to 15 alleles per locus and heterozygosities in the range of 0.46 to 0.89. Mendelian inheritance was confirmed for all four loci in 10 Pied Flycatcher and 2 Barn Swallow families comprising a total of 240 meioses. The occurrence of nonparental alleles in offspring from two Barn Swallow families was consistent with extrapair fertilization as revealed by a parallel DNAfingerprinting analysis. A DNA amount approximately corresponding to 0.01/•1 blood was used for PCR analysis. DNA was also prepared from feathers and approximately 1% of a preparation from a single remex or rectrix was sufficient for PCR amplification. One of the primer pairs from the Barn Swallow also amplified a polymorphic locus in the House Martin (Delichon urbica) and in the Bank Swallow (R. riparia). Received 3 October 1991, accepted 16 June 1992.