Differentiation and levels of genetic variation in northern European lynx (Lynx lynx) populations revealed by microsatellites and mitochondrial DNA analysis

The European lynx (Lynx lynx) has experienced significant decline in population numbers over large parts of its former distribution area in central and northern Europe. In Scandinavia (Sweden and Norway), the species has been subject to intense hunting and in the early 20th century the population size may have been as low as about 100 animals. During the rest of the century there have been alternating periods of restricted hunting and total protection. Future management of the Scandinavian lynx population will require insight into what effects demographic bottlenecks may have had on genetic variability and structure. For this purpose, 276 lynxes from Sweden, Norway, Finland, Estonia and Latvia were analysed for polymorphism at 11 feline microsatellite loci and at the mitochondrial DNA (mtDNA) control region. Scandinavian lynxes were found to be fixed for a single mtDNA haplotype, while this and three additional haplotypes were seen in Finland and the Baltic States (Estonia and Latvia); the haplotypes were all very similar, only differing at 1-4 sites within a 700 bp region sequenced. Microsatellite variability was moderate (H-e = 0.51-0.62) with lower heterozygosity and fewer alleles in Scandinavia than in Finland and the Baltic States together, though significant so only for the latter. Heterozygosity data in Scandinavia were consistent with a recent population bottleneck. Various analyses (e.g. F-st, individual-based tree, assignment test) revealed distinct genetic differentiation between Scandinavian lynxes and animals from Finland and the Baltic States. Some structure was evident within Scandinavia as well, suggesting an isolation by distance. The observed partition of genetic variability between Scandinavia and the eastern countries thereof indicates that lynx populations from the two regions may need to be separately managed. We discuss what factors can have contributed to the population genetic structure seen in northern European lynx populations of today.