Plant & Animal Genomes XI Conference

January 11-15, 2003
Town & Country Convention Center
San Diego, CA

Poster: Natural Populations
            

LOW FREQUENCY OF MICROSATELLITES IN COMMON LOON (Gavia immer) GENOME

Department of Environmental and Population Health, Tufts University School of Veterinary Medicine, North Grafton, MA 01536

We report here the first microsatellites from the common loon (Gavia immer) genome. A total of 224 recombinant clones were isolated from a genomic library of the common loon that were directly sequenced without probe hybridization. One hundred and five clones contained 192 short sequence repeats (SSRs), or microsatellites, with three or more repeats. The majority of motifs were quite short, with a maximum of eight repeats. Microsatellite motifs with three repeats represented 88.5% of all 192 sequences. Only 1.5% of motifs were longer than three repeats. Di-nucleotide motifs were by far the most common (87.5%), followed by tri- (10.9%), tetra- (1.0%), and hexa-nucleotides (0.52%). Eighteen primer sets were designed and tested for polymorphism at a single annealing temperature of 52ēC, 15 (83.3%) of which successfully amplified bands, but most need further optimization. Two (13.3%) of the 15 primers showed polymorphism when genotyped in twelve common loons presented at Tufts University School of Veterinary Medicine Wildlife Clinic. These 12 samples represent the species ranging from Maine, New Hampshire, Massachusetts and Connecticut. The results suggest that these microsatellites will be useful in population genetic studies. Additional markers are also being developed to construct a low-density genetic map for the common loon.