Joshi Bheem Dutt, Matura Rakesh, M A Predit, De Rahul, Pandav Bivash, Sharma Vipin, Nigam Parag, Goyal Surendra Prakash
Wildlife Institute of India, Dehradun, Uttakrakhand, India.
Mitochondrial DNA B Resour. 2018 Feb 15;3(1):245-249. doi: 10.1080/23802359.2018.1436990.
Genetic analysis is an important tool in understanding population structure, genetic diversity, and phylogenetics of endangered species likely to be affected by microevolution and anthropogenic factors. Western Ghats landscape is one of the identified biodiversity hotspots in India, and micro-evolutionary processes are observed in this landscape due to the presence of the gaps in the mountain ranges. Nilgiri tahr is endemic to and distributed in this landscape while very little is known about genetic characteristics, population structure and impact of these gaps on the species. In the present study, two different populations of Nilgiri tahr from the north (NPG) and south (SPG) of Palghat gap (PG) were studied using the cytochrome b gene (Cyt b; 310 bp) of mtDNA genome in the Western Ghats, India. Two variable sites were observed in the Cyt b fragment while the mean pairwise genetic distance between these two populations was 0.007. All the samples phylogenetically clustered in either north or south of PG. The presence of shallow divergence indicates the presence of suitable habitat in past which may have facilitated movement between NPG and SPG. A subsequent change in Paleo-climatic conditions and gradual formation of PG may have resulted in population diversification during the Pleistocene. Besides, Forensically Informative Nucleotide Sequence (FINS) observed would help in geo-assigning any individual from NPG or SPG to understand the likely influences on population demography due to poaching.
遗传分析是理解可能受微进化和人为因素影响的濒危物种的种群结构、遗传多样性和系统发育的重要工具。西高止山脉地区是印度已确定的生物多样性热点地区之一，由于山脉存在缺口，在该地区观察到了微进化过程。尼尔吉里塔尔羊是该地区特有的物种且分布于此，但人们对其遗传特征、种群结构以及这些缺口对该物种的影响知之甚少。在本研究中，利用印度西高止山脉线粒体DNA基因组的细胞色素b基因（Cyt b；310 bp），对来自帕尔加特缺口（PG）北部（NPG）和南部（SPG）的两个不同的尼尔吉里塔尔羊种群进行了研究。在Cyt b片段中观察到两个可变位点，而这两个种群之间的平均成对遗传距离为0.007。所有样本在系统发育上聚为PG的北部或南部。浅度分化的存在表明过去存在适宜的栖息地，这可能促进了NPG和SPG之间的迁移。古气候条件的后续变化以及PG的逐渐形成可能导致了更新世期间的种群多样化。此外，观察到的法医信息核苷酸序列（FINS）将有助于对来自NPG或SPG的任何个体进行地理定位，以了解偷猎对种群人口统计学可能产生的影响。
