Individual identification of Amur tigers via non-invasive molecular genetic techniques

Individual identification of Amur tigers via non-invasive molecular genetic techniques

2 April 2014

A non-invasive molecular genetic technique for the individual identification of Amur tigers has been developed under the Amur Tiger Programme in the Russian Far East. It has been used to determine the number, gender and kinship of tigers in the Ussuri Nature Reserve of the Russian Academy of Sciences’ Far Eastern branch.

 

A comparison of the results of the recovery, amplification and analysis of cell nucleus DNA from different samples (blood, fur and droppings) has revealed a considerable semblance in the length of the microsatellite DNA sequences. This means that droppings and fur collected in the Amur tiger’s native habitat can be used for the individual identification of these animals.

 

Droppings, urea and fur are widely used in the molecular genetic study of wild populations. A molecular genetic analysis is complicated because the predators’ droppings include both their own DNA and that of their prey. Therefore, scientists only use colorectal epithelial mucus from the droppings’ outer layer to identify the DNA of the animal being studied. The samples of blood, fur and droppings of the Amur tiger were collected in the Far East to improve the molecular genetic technique of non-invasive identification.

 

The study of tiger droppings using this technique has shown that there are six or seven tigers in the area, which means that this method can be used to identify Amur tigers. However, a polymerase chain reaction-based identification method includes many variables and so can lead to erroneous conclusions due to the small amount of cell nucleus DNA that can be recovered from animal droppings. Hence, several series of tests should be done to reduce the number of possible errors. Another important element is the preservation of DNA invariance in samples. It is very difficult to say if a given sample is eligible for analysis, so the best option is to use the collected samples within two or three days at the most.

 

Furthermore, these data show that molecular genetic techniques can be used to determine parentage and genetic relationship in distinct groups of Amur tigers.

 

These data will be added to the Amur tiger’s genetic database collected in different areas using the non-invasive techniques. In addition to resolving some environmental issues, these techniques can be used for forensic and nature protection purposes, because the Amur tiger is a rare species included in Russia’s Red Data Book.

 

Authors: V.V. Rozhnov., P.A. Sorokin, S.V. Naidenko, V.S. Lukarevsky, Jose A. Hernandez-Blanco, M.N. Litvinov, A.K. Kotlyar, V.G. Yudin