Utility of chicken-specific microsatellite primers for mapping the turkey genome

As part of the University of Minnesota's initiative to map the turkey genome, we are currently evaluating chicken microsatellite loci for use in mapping the turkey genome. To date, 141 primer pairs have been tested for amplification at six different combinations of temperature and MgCl₂ concentration. Micro satellite primer pairs from the Chicken Comprehensive Mapping Kit #2, and additional unpublished chromosome 1 and 2 primers were screened. Analyzable PCR products were produced from 78 of the 141 (55%) primer combinations. In the majority of cases (68%), PCR fragments obtained from the turkey were similar in size to respective chicken loci. The presence of dinucleotide repeats (CA/TG repeats) was determined by Southern hybridization with a (TG)₁₅ oligonucleotide probe. Five of 12 (41.6%) turkey fragments hybridized under low stringency conditions. The length of the dinucleotide repeats in the turkey, relative to the chicken sequences, were found to correspond directly with hybridization intensity. Amplification of homologous loci was confirmed by direct sequencing and subsequent alignment of the turkey and chicken sequences. The results of this study indicate that the use of chicken-specific microsatellite primers will rapidly and significantly enhance construction of a genetic map for the turkey.