Environmental and Comparative Genomics Section, Department of Environmental and Population Health, School of Veterinary Medicine, Tufts University, North Grafton, MA, USA
The bald eagle (Haliaeetus leucocephalus) is currently classified as threatened in the lower 48 United States. In Massachusetts, only 12 active nesting sites presently exist, and the majority of breeding birds originated from a population of eaglets imported from Nova Scotia in the 1980s. Previous work using random amplified polymorphic DNA (RAPD) demonstrated a genetic diversity among Massachusetts eagles of only 22%. The RAPD technique, while useful for genetic analysis of blood samples, proved inappropriate for analysis of feather samples from the same birds. To address this, our current work aimed at determining whether microsatellites would yield identical information for blood and feather samples. Utilizing GenBank sequences, 24 microsatellite primer sets representing 18 loci were designed and tested for polymorphism using DNA from eight blood samples and a single PCR annealing temperature. Thirteen microsatellites (54%) representing 11 loci were polymorphic, and three of these were selected to compare allele sizes in blood and feather DNA from the same eaglet. Preliminary results using microsatellite AJ620425 showed that 18 out of 44 blood/feather pairs amplified alleles of similar sizes. Feather DNA of the other 26 blood/feather pairs tested did not amplify any alleles. Data suggest that microsatellite alleles from blood and feather of the same bird may be consistent; however, multiple repetitions of the experiment are needed in order to determine optimum DNA concentration for feather samples. Additionally, we will need to refine the protocol so as to obtain greater amplification of feather DNA which tended to give somewhat weak signals.