High Mutation Rates in Canine Tetranucleotide Microsatellites: Too Much Risk for Genetic Compatibility Purposes?

The use and convenience of canine tetranucleotide microsatellite markers for forensic purposes is addressed. These are commonly used in human genetics due to their high polymorphism, ease of laboratorial management and low mutation rates. However, care should be taken before including these markers in canine panels due to the high mutation rates shown in this species and the risk of errors in paternity assignment. To answer this question a panel including 16 markers (8 of them tetranucleotides) were typed for the family members of the Dogmap Project reference panel, and their mutation rates calculated. The effect these rates would have in terms of the increase in the number of false positives is assessed. Excluding one single marker with extreme mutation rate from the panel considerably improves the average rate and the performance of the panel. Therefore, a careful examination of the mutational behaviour of the candidate markers is advised for any marker panel design, even prior to the assessment of their polymorphism.