Genetic structure of sub-ethic groups of newar population of Kathmandu valley

Abstract

Diversity in geographical region, physical environment, flora, and fauna including humans in Nepal has offered suitable platforms to study their origin and genetic relationship. There are very few studies on the populations of Nepal. To understand their genetic structure and affinities, for the first time, we studied Shakya (N = 19), Bajracharya (N = 20) and Udaaya (N=59) population of Newar ethnic group using high resolution Y Chromosomal, Mitochondrial and Autosomal DNA markers. About 10 ml of blood samples were collected from 98 healthy and unrelated individuals, inhabiting Kathmandu Valley with their informed written consent. DNA was extracted from the whole blood with the standard phenol-chloroform method and target regions were amplified using Polymerase chain reaction (PCR). Y-chromosomal Biallelic markers were used to dissect the paternal lineages and whole mitochondrial genome was sequenced and the variations were scored against the revised Cambridge Reference Sequence (rCRS) to trace the maternal lineages. Based on the variations, putative Haplogroups were assigned and were confirmed by coding region markers. Our mtDNA result indicates the dominance of Macrohaplogroup M (90%: includes M2, M3, M5, M9, M30, M33, M35, M38, Z, D, etc.) along with the branches of R (R6, R9) and U (U2 and U7) Haplogroups. Their maternal Genepool was found to harbour around 50% of South Asian, 25% East/Southeast Asian and 20% Central Asian specific Genepool. West Eurasian haplogroup were negligible (5%). Y-chromosome analysis revealed the presence of major haplogroups such as M117-O3a3, M17-R1a, M82-H1, M15-D1 and M124-R2. Overall, South Asian and East/Southeast Asian signature were found prominent among the Newars. The analyses of Autosomal markers (MYBPC3, LCT, SLC24A, EDAR, etc.) showed that the genetic structure of Newar population is more or less similar to the Indian Tibeto-Burman populations. In conclusion, the Newar population of Nepal was found to harbour prominent Genepool from South Asia, East/ Southeast Asia. Further, analysis on Y-STRs and high density Autosomal markers will help in tracing the precise origin and affinity of the Newar population of Nepal. Key Words: Biallelic marker, Haplogroup, Genepool, Autosomal Marker, Y-STR, rCRS