Potential of inter- and intra-species variability of CHD1 gene in birds as a forensic tool

Abstract

Nowadays, illegal trafficking and smuggling of animals are among the greatest threats to many avian species. Most commonly smuggled birds belong to parrots, song birds, raptor species and owls. All of these species are protected by national and international legislations. In order to prevent and reduce wildlife trafficking, DNA methods have become an important forensic tool in species and sex identification. In this study, CHD1R/CHD1F primer pair was used to amplify a part of the CHD1 gene from 65 birds that belong to 43 species. For 36 species this is the first time that the length of CHD1 amplicons was measured for the purpose of species determination. The results were visualized using capillary electrophoresis and enabled simultaneous determination of sex and species. Based on the number of amplicons (two in females, one in males) sex was successfully determined in all species, even in cases where gel electrophoresis failed to give results. Moreover, the species was successfully determined in most bird species based on the species-specific sizes of CHD1 amplicon. The method used in this study is of great importance for veterinary forensic medicine and the prevention of wildlife smuggling. Still, further work is necessary to confirm the effectiveness of the method in all bird species.

Ilegalna trgovina i krijumčarenje divljim vrstama danas predstavlja jednu od najvećih pretnji koje ugrožavaju populacije velikog broja ptica. Najčešće vrste kojima se ilegalno trguje su papagaji, ptice pevačice, grabljivice i sove. Sve ove vrste ptica su zaštićene nacionalnim ili međunarodnim zakonskim regulativama. U cilju prevencije i smanjenja ilegalne trgovine, molekularne metode su postale bitno forenzičko oruđe u identifi kaciji vrste i pola zaštićenih vrsta ptica. U ovom istraživanju ispitano je ukupno 65 uzoraka ptica (ukupno 43 vrste), a u cilju umnožavanja dela CHD1 gena korišćen je CHD1R/CHD1F par prajmera. Za 36 vrsta ovo je prvi put da je dužina CHD1 gena određivana u cilju identifi kacije vrste. Dobijeni produkti su vizuelizovani koristeći kapilarnu elektroforezu i omogućili su simultano određivanje pola i vrste. Na osnovu analize amplikona (dva kod ženke, jedan kod mužjaka), pol je uspešno identifi kovan kod svih vrsta, čak i kod onih kod kojih gel elektroforeza nije bila uspešna.Vrsta je uspešno određena kod većine ptica na osnovu veličine CHD1 amplikona specifične za vrstu. Metoda korišćena u ovoj studiji je od velikog značaja u veterinarskoj forenzici i prevenciji ilegalne trgovine životinjama. Ipak, dalji rad na ovoj metodi je neophodan da bi se potvrdila efi kasnost metode na svim vrstama ptica.