Structure analysis of 85 dog breeds. Cluster results from a structure analysis of 414 dogs from 69 breeds and based on 96 microsatellite markers. Each breed was usually represented by five dogs, and all dogs were unrelated to one another at the grandparent level. Structure implements a Bayesian model-based clustering algorithm that attempts to identify genetically distinct subpopulations based on patterns of allele frequencies (Pritchard et al. 2000). Each genotyped dog is represented by a single vertical line divided into K colors, where K is the number of clusters assumed in each structure analysis. The length of the colored segment represents the individual's estimated proportion of membership in that cluster (Parker et al. 2004). At K = 4, four clusters are clearly defined representing genetically distinct breed grouping within the domestic dog (see text).
