Genetic variation in local Swedish sheep breeds

Abstract: Sheep have played a very important part in rural history. In Sweden there were many kinds of small native breeds, kept for their meat and fleece. Women cared for the flock that often had very little to feed on during the cold and sometimes harsh winter months. This meant that these sheep over time acquired special phenotypic properties depending on the environment they lived in, and easily fed compared to modern breeds kept for meat. Most of these sheep have since become extinct. Since the rediscovery of the 9 breeds we have today, a lot of work has been done to preserve the biological diversity of them. It is a certainty that sheep are inbred within each breed, since there were very few individuals to start off with. It is however not known how closely related the breeds are. Each breed has been named by the area it has been rediscovered in and, if more than one group of individuals has been found, their phenotypic similarities have decided which breed they belong to. The aim of this study was to determine kinship by genetic variability between the breeds using 18 microsatellites as genetic markers. Blood samples were collected from at least 2 different flocks and at least 15 individuals of each breed (with the exception of Fjällnäs and Gestrike sheep). Individuals closely related to founder parents were preferably chosen, as well as individuals from different families. The results of this study showed a rather surprising genetic diversity between each breed, involving at least one unique allele in all breeds. Though the sample range is questionable with it being small and many individuals being closely related, there is also a variability of alleles within each breed therefore acknowledging that all these breeds should if possible be kept from interbreeding.