Genomic blueprint of population of Rajasthan based on autosomal STR markers

Aim: Genetic diversity and forensic efficacy of 20 autosomal STR genetic markers were investigated in a highly diverse population of Rajasthan, a state in north-western India.Subjects and methods: In this study, 317 blood samples from unrelated healthy individuals were directly amplified using the PowerPlex^® 21 multiplex system (Promega). Amplified products were separated by capillary electrophoresis using a Genetic Analyser -3500 XL (Thermo Fisher Scientific). The data thus obtained was statistically analysed using population genetic software.Results: The studied population showed genetic affinity with the geographically close populations. The locus Penta-E was found to be the most polymorphic with a value of 0.90 in the studied population. The combined discrimination power (CPD) and combined power of exclusion (CPE) were observed as >0.999999999 and 0.999999997, respectively, for all the studied 20 autosomal STR loci. The combined probability of match (CPm) was 1.39 × 10^-25 and combined paternity index (CPI) was 3.66 × 10⁸ for all the studied loci.Conclusion: The results conclusively support the hypothesis that the studied autosomal STR loci are polymorphic in nature and, besides being useful in forensic applications they can also be applied in anthropological and other population genetic studies. This study supports the 'isolation-by-distance' model. Genetic data obtained from this study will enrich the population data bank.

Genetic dissection of five ethnic groups from Punjab, North-West India-A study based on Autosomal Markers

The present study assessed the applicability of Alu insertion elements and Single Nucleotide Polymorphisms (SNPs) in forensic identification and estimated the extent of genetic variation in five major ethnic groups of Punjab, North-West India. A total of 1012 unrelated samples belonging to Banias, Brahmins, Jat Sikhs, Khatris and Scheduled Castes were genotyped for four Alu elements (ACE, APO, PLAT, D1) and six Single Nucleotide Polymorphisms [ESR (PvuII), LPL (PvuII), HTR2A (MspI), DRD2 Taq1A, Taq1B, Taq1D]. Allele frequencies observed heterozygosity and forensic efficacy parameters were determined. The data on the genetic affinity of the studied populations among themselves and with other populations of India was also analysed using a Neighbor-Joining tree and multidimensional scaling plot respectively. All the 10 loci were polymorphic and their average observed heterozygosity ranged from 0.3872 (Banias) to 0.4311 (Scheduled Castes). Allele frequency variation at the 9 out of 10 loci led to statistically significant pairwise differences among the five study population groups. The result from AMOVA, Structure analysis, and Phylogenetic tree suggests that these populations are homogenous. In the multidimensional scaling plot, the present study populations formed a compact cluster clearly separated from other populations, suggesting a unique genetic identity of the Punjab populations as a whole. All these observations suggest that either a recent common origin of these populations or extensive gene flow across the populations that dissolve the original genetic differences. The data generated in this study will be useful for forensic genetics, molecular anthropological and demographic studies.