Genetic variation in caribou and reindeer (Rangifer tarandus)

Area of Science:

• Genetics
• Wildlife Biology
• Conservation Science

Background:

• Understanding genetic diversity in wild and domestic populations of Rangifer tarandus is crucial for effective management and conservation.
• Microsatellite DNA markers are valuable tools for assessing population structure and gene flow in ungulates.

Purpose of the Study:

• To quantify genetic variation at seven microsatellite DNA loci in wild caribou and domestic reindeer populations.
• To assess population structure, genetic differentiation, and gene flow among herds across North America, Scandinavia, and Russia.

Main Methods:

• Microsatellite DNA analysis was performed on samples from 19 herds of wild caribou and domestic reindeer.
• Allelic diversity and heterozygosity were calculated for each locus within each herd.
• Population genetic statistics were used to infer population structure and gene flow.

Main Results:

• Most herds exhibited moderate to high genetic variation, with an average of 2.0-6.6 alleles per locus and observed heterozygosity of 0.33-0.50.
• A herd on Svalbard Island, Scandinavia, showed exceptionally low genetic diversity.
• Caribou herds in Alaska (Central Arctic, Western Arctic, Porcupine River) form a single breeding population.
• Domestic reindeer in Alaska and Siberia showed distinct allele frequencies but low genetic differentiation.
• Significant genetic differences were found between wild caribou and domestic reindeer in Alaska, indicating limited historical gene flow.

Conclusions:

• Genetic variation in Rangifer tarandus populations is geographically structured, with some unique genetic profiles (e.g., Svalbard herd).
• Wild caribou and domestic reindeer in Alaska represent genetically distinct populations with restricted gene flow.
• The findings have implications for the management and conservation of both wild caribou and domestic reindeer populations in Alaska and beyond.