[Whole sequence analysis of brain-derived neurotrophic factor gene in Asiatic Black Bear through faecal sampling]

Using our lab's improved protocol for faecal DNA extraction, the entire 753-bp DNA coding sequence of the nuclear brain-derived neurotrophic factor (BDNF) gene was cloned for the first time from Asiatic Black Bear Selenarctos thibetanus faecal samples with primers based on the reported sequence of the Malayan Bear BDNF gene. Hair was used as a positive control and the experiments were repeated several times to obtain reliable and identical results. Sequence analysis showed that the BDNF gene of Asiatic Black Bear was highly conserved compared to those of human and giant panda, with an identity of 94.5% and 98.9%, respectively. The deduced amino acid sequence of the mature protein was found to be identical to those of all the reported mammalians. According to gene sequence alignment, the giant panda appeared to be phylogenetically closer to Asiatic Black Bear than the lesser panda. This study represents the first time that a non-invasive method such as faecal sampling was used to analyze a functional nuclear BDNF gene of Asiatic Black Bear. It will not only provide important reference for the conservation and breeding of Asiatic Black Bear and open up new avenues of non-invasive sampling in the study of endangered wildlife, but also provide another molecular evidence for the study of relationship of Asiatic Black Bear and its related species.