Identification of Genetic Variation on the Horse Y Chromosome and the Tracing of Male Founder Lineages in Modern Breeds
Figure 3
Geographic distribution and history of Y-haplotypes in modern horse breeds.
(a) Geographic distribution of Y-chromosomal haplotypes in a set of modern horse breeds. Only a few important breeds are specified, the full list with information on breeds and HT frequencies is given in Table S7. (b) Origin of modern domestic horse founders deduced from pedigree data. Each founder is represented by a drum with its size proportionally to the number of offspring in the dataset. The number in the drums serve as founder identifiers. Detailed information on founders (name, year of birth, breed, origin, information on import) is listed in Table 1. (c) Male introgression routes deduced from the pedigree and the distribution of HT2 and HT3 in our dataset. HT2 (yellow arrows) arrived from South-East at early times and has been spread during the Neapolitan and Oriental introgression waves, but did not reach Northern Europe and the Iberian peninsula. The English wave in red is well documented through pedigree data and the spread of HT3 (red arrows). Due to the ubiquitous occurrence of HT1, this haplotype is not considered. The black solid lines reflect the limits of the observation of HT2 and HT3.