STR Typing of European Elk (Moose) and European Roe Deer with Novel Forensic Assays Reveals Contrasting Patterns of Genetic Structure of the Two Cervids in Belarus

摘要

Abstract Cervids are popular game mammals and frequent victims of poaching in Europe. Investigation into illegal hunting and commercialisation often requires not only species identification, but also assignment of animal samples to an individual. For the purpose of wildlife forensic identity testing, we developed DNA typing assays for two common cervid species of Europe: European elk (Alces alces) and European roe deer (Capreolus capreolus), which comprised 16 and 12 short tandem repeats (STRs), respectively. The assays were tested for robustness in individualisation of biological samples based on data from 386 elk and 360 roe deer from all administrative regions of Belarus. Analysis of molecular variance revealed almost countrywide genetic homogeneity of elk and significant genetic differentiation of local roe deer. Reduced genetic diversity in European elk from Belarus compared to Siberia and historically documented massive population decline followed by rapid expansion explain the observed genetic structure as legacy of homogeneous genetic substrate inherited from a small ancestral population after genetic bottleneck in the 1920s. On the other hand, the observed geographic stratification of European roe deer is likely to result from numerous genetic drifts and/or local interspecies gene flow with Siberian roe deer (Capreolus pygargus), driven both naturally and artificially by large-scale releases of individuals of both roe deer species in Eastern Europe in the 20th century. Power of discrimination of unrelated individuals based on the pan-Belarusian database for European elk was higher than 0.99999999999. In case of regional databases for European roe deer, the value exceeded 0.999999999. Our results demonstrate the developed STR assays to be highly efficient tools for verification of genetic identity of cervid specimens, even in case of populations which suffered from massive population decline. To our knowledge, this is the first study presenting genetic identity testing assays for European elk and roe deer samples with a number of STR markers and statistical parameters sufficient to generate extremely strong DNA evidence in wildlife forensic casework, which were used to characterise genetic structure on a broad countrywide scale.