- Aim of the study and expected results: We will study the genetic development and status of the North Swedish Spitz breeds, by comparing the genetic diversity of today's dogs with the diversity of the original population of non-breed dogs that lived 100 years or more ago, from which today's breeds originated. We will do this by performing DNA analysis of skins from this historic dog population, obtained from clothes used by both the Swedish and the Saami populations, and comparing the genome sequences of the historic population and the modern breeds. Hereby, we obtain exact measurements of the genetic difference between the historical and the modern populations, concerning, e.g., the amount of genetic diversity, level of inbreeding, heterozygosity and frequency of deleterious alleles. Based on this, we can draw conclusions about how the breeding process has affected the genetic status of the modern dog breeds. These results will lay a foundation for the breeding programs of the North Swedish Spitz breeds, and will be of significance for veterinary research for tracing genetic diseases and for identification of the genetic reasons behind the phenotypes. Importantly, this is to our knowledge the first study where the evolution of dog breeds is studied based on a comparison between the original and the derived population. This will give unique knowledge about how dog breeds develop from a non-bred source population, and how this affects genetic diversity and inbreeding in dog breeds, of importance for the management of dog breeds in general. The study will have a broad interdisciplinary scientific significance, of great importance for illuminating an important part of human history, and giving important building blocks for understanding the mechanisms behind breeding and evolution. -Specific goals: - Describe the genetic development and status of the North Swedish Spitz breeds, by comparing the genetic diversity of today's dogs with the diversity of the original population of non-breed dogs. - Measure how the breeding process has affected the modern breeds concerning amount of genetic diversity, level of inbreeding, heterozygosity and frequency of deleterious alleles. - Unravel the origin and relations of the North Swedish Spitz breeds. - Describe, for the first time, the genetic evolution behind the development of dog breeds, based on actual genetic comparison of the original non-breed population and the resulting dog breeds. Materials and methods: We have samples from 144 different dog skins, obtained from local museums, hembygdsföreningar and private individuals across north Sweden. The skins come mainly from clothes, for example from fur details on Saami kolts and from "forbonde" coats and are 100-200 years old. We will sequence the nuclear genome with 1x coverage for all samples giving also the mtDNA genome with >100x coverage, and 50 samples will be sequenced with 10-15x coverage of the nuclear genome. The genome sequences will be compared to existing datasets, from 120 dogs and wolves from across the world, including 33 dogs from Scandinavian spitz breeds and 30 dogs from other polar spitz breeds.