Identification of novel haplotypes and interpretation of gene flow of mitochondrial DNA control region of Eurasian otter (Lutra lutra) for the effective conservation.

The number and distribution of Eurasian otters have declined during twentieth century due to human activity and water pollution. The global conservation status of Eurasian otter is presently 'Near Threatened (NT)' and strictly protected by being listed on the international legislation and conventions. A number of studies using the mitochondrial DNA (mtDNA) control region (CR) have been conducted in order to effectively apply conservation and reintroduction programs, especially in Europe. However, aside from Europe, there have been few studies concerning genetic diversity and phylogeny of Eurasian otters. Therefore, in this study, we sequenced partial mtDNA CR sequences (232 bp) from five South Korean Eurasian otters and analyzed 27 otters originating from parts of northeast Asia (South Korea, China, Japan and Russia (Sakhalin)), and Europe. Out of 232 bp partial mtDNA CR sequences, 13 polymorphic sites (5.6%) were identified and 4 novel mtDNA CR haplotypes (Lut16-19) were discovered from 12 Eurasian otters originating from northeast Asian region. In this study, a comprehensive analysis of genetic diversity and population structure of Eurasian otter between Europe and northeast Asia continents were conducted. Of these, different past demographic histories in Pleistocene period might have largely impacted the genetic structure of each population differently. In addition, low degree of gene flow, isolation by distance (IBD) pattern from geographically wide distanced dataset and analysis of molecular variance (AMOVA) also represented distinct genetic characteristics of Eurasian otter between Europe and northeast Asia.