Riverine barrier effects on population genetic structure of the Hanuman langur (Semnopithecus entellus) in the Nepal Himalaya.

BACKGROUND: Past climatological events and contemporary geophysical barriers shape the distribution, population genetic structure, and evolutionary history of many organisms. The Himalayan region, frequently referred to as the third pole of the Earth, has experienced large-scale climatic oscillations in the past and bears unique geographic, topographic, and climatic areas. The influences of the Pleistocene climatic fluctuations and present-day geographical barriers such as rivers in shaping the demographic history and population genetic structure of organisms in the Nepal Himalaya have not yet been documented. Hence, we examined the effects of late-Quaternary glacial-interglacial cycles and riverine barriers on the genetic composition of Hanuman langurs (Semnopithecus entellus), a colobine primate with a wide range of altitudinal distribution across the Nepalese Himalaya, using the mitochondrial DNA control region (CR, 1090 bp) and cytochrome B (CYTB, 1140 bp) sequences combined with paleodistribution modeling. RESULTS: DNA sequences were successfully retrieved from 67 non-invasively collected fecal samples belonging to 18 wild Hanuman langur troops covering the entire distribution range of the species in Nepal. We identified 37 haplotypes from the concatenated CR + CYTB (2230 bp) sequences, with haplotype and nucleotide diversities of 0.958 ± 0.015 and 0.0237 ± 0.0008, respectively. The troops were clustered into six major clades corresponding to their river-isolated spatial distribution, with the significantly high genetic variation among these clades confirming the barrier effects of the snow-fed Himalayan rivers on genetic structuring. Analysis of demographic history projected a decrease in population size with the onset of the last glacial maximum (LGM); and, in accordance with the molecular analyses, paleodistribution modeling revealed a range shift in its suitable habitat downward/southward during the LGM. The complex genetic structure among the populations of central Nepal, and the stable optimal habitat through the last interglacial period to the present suggest that the central mid-hills of Nepal served as glacial refugia for the Hanuman langur. CONCLUSIONS: Hanuman langurs of the Nepal Himalaya region exhibit high genetic diversity, with their population genetic structure is strongly shaped by riverine barrier effects beyond isolation by distance; hence, this species demands detailed future phylogenetic study.

Multilocus approaches reveal underestimated species diversity and inter-specific gene flow in pikas (Ochotona) from southwestern China.

The phylogeny of living pikas (Ochotonidae, Ochotona) remains obscure, and pika species diversity in southwestern China has never been well explored. In this study, 96 tissue samples from 11 valid species in three classified subgenera (Pika, Ochotona and Conothoa) from 23 locations were characterized using multilocus sequences of 7031bp. Two mitochondrial (CYT B and COI) and five nuclear gene segments (RAG1, RAG2, TTN, OXAIL and IL1RAPL1) were sequenced. We analysed evolutionary histories using maximum likelihood (RAxML) and Bayesian analyses (BEAST), and we also used molecular species delimitation analyses (BPP) to explore species diversity. Our study supported O. syrinx (O. huangensis) as a distinct clade from all named subgenera. Relationships among subgenera were not fully resolved, which may be due to a rapid diversification in the middle Miocene (∼13.90Ma). Conflicting gene trees implied mitochondrial introgression from O. cansus to O. curzoniae. We uncovered three cryptic species from Shaanxi, Sichuan and Yunnan with strong support, suggesting an underestimation of species diversity in the "sky-island" mountains of southwest China.

Multilocus phylogeny suggests a distinct species status for the Nepal population of Assam macaques ( Macaca assamensis): implications for evolution and conservation.

Phylogenetic relationships within the sinica-group of macaques based on morphological, behavioral, and molecular characteristics have remained controversial. The Nepal population of Assam macaques ( Macaca assamensis) (NPAM), the westernmost population of the species, is morphologically distinct but has never been used in phylogenetic analyses. Here, the phylogenetic relationship of NPAM with other congeners was tested using multiple mitochondrial and Y-chromosomal loci. The divergence times and evolutionary genetic distances among macaques were also estimated. Results revealed two major mitochondrial DNA clades of macaques under the sinica-group: the first clade included M. thibetana, M. sinica, and eastern subspecies of Assam macaque ( M. assamensis assamensis); the second clade included M. radiata together with species from the eastern and central Himalaya, namely, M. leucogenys, M. munzala, and NPAM. Among the second-clade species, NPAM was the first to diverge from the other members of the clade around 1.9 million years ago. Our results revealed that NPAM is phylogenetically distinct from the eastern Assam macaques and closer to other species and hence may represent a separate species. Because of its phylogenetic distinctiveness, isolated distribution, and small population size, the Nepal population of sinica-group macaques warrants detailed taxonomic revision and high conservation priority.

First report of malaria parasites in water buffalo in Nepal.

We present the first molecular-based report on ungulate malaria parasites from water buffalo in Nepal. Fifty-six blood samples were collected from different groups of water buffalo (wild, feral, and domestic) and PCR assays were conducted using Plasmodium spp. cytb specific primers. Two positive cases were detected, one each from feral and domestic individuals. Complete mitochondrial genome sequence (5987 bp) was obtained and examined for nucleotide variations. Sequence analysis revealed identity with type II water buffalo malaria parasites, reported previously, with one A to T nucleotide difference at position 5344. Prevalence, as well as possible economic impacts of water buffalo malaria, should be determined on a wider set of samples from buffalo across Nepal.