Use of molecular-based approach in resolving subspecies ambiguity of the rescued tiger cubs from Arunachal Pradesh, India and their relationship with other population

摘要

Genetic approach is often suggested for resolving taxonomic ambiguities in areas where there have been overlaps in distribution of a species or subspecies. The Northeast part of India is one of the identified biodiversity hotspots, having the junction of Palearctic and Indomalyan realms with dense canopy forests and rugged terrains. The distribution range of two tiger subspecies, i.e. Bengal tiger and northern IndoChinese tiger, overlaps with each other in this region. The government authorities rescued three tiger cubs from Angrim Valley Village, Arunachal Pradesh, Northeast India in November 2012. We carried out a comprehensive genetic study on the rescued cubs to elucidate their subspecies status and determine their relationship with the remnant tiger populations. Our findings based on 3661 base pair of mitochondrial DNA sequence spanning across six mitochondrial genes (ND1, ND2, ND5, ND6, 12S rRNA and CytB) and non-coding control region (CR) suggest the Bengal tiger ancestry of the rescued tiger cubs. Further, comparison of mitochondrial haplotype with other Bengal tiger populations reveals that the haplotype reported for the rescued cub is novel and has close affinity to the northeast tiger populations of India. However, detailed population assignment to infer the source of origin was not possible due to lack of genetic data for all Bengal tiger populations. The present study attempts an assessment of tiger status that has resulted in identification of another tiger occupied landscape in India (Dibang Tiger Reserve).