Effects of anthropogenic intermixing on the genetic structure of Dybowski's frog populations in northeast China

Abstract

The Dybowski's frog (Rana dybowskii) is mainly distributed in northeast China and the Russian Far East. Its dried oviduct, or frog oil, has been used in traditional Chinese medicine for thousands of years. Frogs from different geographic regions exhibit variations in their body mass and oil productivity. As a result, farmers usually import high quality breeding stock from different areas to increase oviduct productivity. This practice could alter the genetic structure of the frog populations. We used 10 microsatellite loci to investigate the level of genetic variation for 10 frog populations in the context of human-mediated disturbance. The study populations comprised the following: the Hebei, Tieli, and Jiamusi populations from the Lesser Khingan Mountains; the Mudanjiang, Jilin, Jiaohe, and Huadian populations from the north central Changbai Mountains; and the Tonghua, Benxi, and Xiuyan populations from the southern Changbai Mountains. Our results showed that the 3 Lesser Khingan Mountain populations exhibited highly significant differentiation values (FST = 0.047–0.071, P < 0.001). In addition, the Tonghua population differentiated significantly from the other 6 populations of the Changbai Mountains (P < 0.001). The genetic differentiation coefficient (FST) and gene flow (Nem) estimates showed that the Benxi and Jiaohe populations had a high degree of genetic similarity despite being geographically separated by mountains and river systems. We obtained similar results for the Xiuyan and Tieli populations. Furthermore, the degree of gene flow between the Jiamusi and the north central Changbai Mountain populations was greater than that observed between the Jiamusi and the other Lesser Khingan Mountain populations. These results therefore suggest that the Benxi, Xiuyan, and Jiamusi populations have undergone substantial intermixing because of human-mediated relocation. Economic demands make completely stopping the geographical relocation of Dybowski's frog in northeast China virtually impossible. Consequently, effective management strategies are now a high priority to ensure that conservationists and local economies can work together to guarantee the long-term survival of this species. © 2013 The Wildlife Society.