Microsatellite variation in Nordic semi-domestic reindeer

We have analyzed DNA microsatellites and the mitochondrial control region
in reindeer from 31 different husbandry areas in Norway, Sweden and
Finland in order to better understand the processes that underlie the
genetic variability of the Nordic domestic herds. The distinct
differentiation found in the nuclear markers but less so in the
mitochondrial marker, gives evidence of an origin from a common ancestral
population which later evolved into the two main gene pools characterizing
the nuclear genomes of domestic reindeer in Finland and most of Sweden and
Norway. Analyses of temporal trends in effective population size gives
evidence of a rapid increase in number of reindeer before the population
growth associated with the pastoral transition. This implies that the
ancestry of contemporary domestic reindeer lay among a rapid growing wild
population possibly located in the boreal areas of eastern Fennoscandia or
European Russia. The evolution of reindeer husbandry in Finland, perhaps
with input from European Russia, which later spread to northern Norway
could explain the shared genomic pattern observed in these areas today.
 The structured selection of productive female-centered herds may
explain the genetic structure in other parts of Norway and in Sweden. The
further sub-structuring of the Swedish/ Norwegian gene-pool appears to
follow the traditional language borders with the South Sámi language
dominating the southern- and the Central Sámi language in the more
northern genetic sub-clusters. This suggests that traditional knowledge,
cultural identities and herd migrations have contributed to shape the
genetic structure seen today. Ecological gradients are more pronounced
within as compared to between the genetic clusters, giving further
evidence that historical and social-cultural processes are important
drivers for the genetic differentiations found in domestic reindeer across
the Nordic countries.