Related Experiment Video
Updated: Jun 23, 2026
13:33
Infinium Assay for Large-scale SNP Genotyping Applications
Published on: November 19, 2013
Fine-scaled human genetic structure revealed by SNP microarrays
Jinchuan Xing1, W Scott Watkins, David J Witherspoon
1Department of Human Genetics, Eccles Institute of Human Genetics, University of Utah, Salt Lake City, UT 84112, USA.
Genome Research
|May 5, 2009
Summary
Human genetic variation is geographically continuous, yet distinct populations show clear genetic differences. This study analyzed over 240,000 single nucleotide polymorphism (SNP) loci in 554 individuals across diverse global populations.
Area of Science:
- Human Genetics
- Population Genetics
- Genomics
Background:
- Understanding human genetic variation is crucial for population studies.
- Previous research has indicated both shared and distinct genetic profiles across human populations.
- Expanding sampling to include underrepresented groups like Indian castes and Daghestanis provides a more comprehensive view.
Purpose of the Study:
- To analyze human genetic variation using a large single nucleotide polymorphism (SNP) dataset.
- To investigate genetic differentiation and relationships among diverse worldwide populations, including specific Indian and Caucasian groups.
- To correlate genetic data with geographic and social factors influencing population structure.
Main Methods:
- Genotyping of over 240,000 SNP loci in 554 individuals from 27 populations using Affymetrix SNP microarrays.
- Application of principal components analysis (PCA) and model-based clustering algorithms to analyze genetic data.
- Inclusion of diverse populations: African, Asian (including Indian castes and Iban), and European (including Daghestanis).
Main Results:
- Significant genetic differentiation was observed among most populations, with individuals accurately classifiable into continental groups.
- Genetic variation showed a correlation with geographic distance, supporting continuous variation.
- High-resolution genetic structure was revealed within Indian caste/tribal groups and between Daghestani populations, highlighting social influences.
Conclusions:
- Human genetic variation exhibits both continuity and discernible population-specific differentiation.
- Genetic classification aligns with continental groupings but can conflict with self-classification in closely related populations.
- Social factors play a significant role in shaping human population structure alongside geography.
Related Concept Videos
02:26Comparing Copy Number Variations and SNPs
Sequencing of the human genome has opened up several best-kept secrets of the genome. Scientists have identified thousands of genome variations that exist within a population. These variations can be a single nucleotide or a larger chromosomal variation.
Copy number variations or CNVs are the structural variations that cover more than 1kb of DNA sequence. The single nucleotide polymorphism (SNP), on the other hand, is a single nucleotide change or a point mutation that is found in more than 1%...
Copy number variations or CNVs are the structural variations that cover more than 1kb of DNA sequence. The single nucleotide polymorphism (SNP), on the other hand, is a single nucleotide change or a point mutation that is found in more than 1%...
01:05Single Nucleotide Polymorphisms-SNPs
A single nucleotide polymorphism or SNP is a single nucleotide variation at a specific genomic position in a large population. It is the most prevalent type of sequence variation found in the human genome. Point mutations that occur in more than 1% of the population qualify as SNPs. These are present once every 1000 nucleotides on an average in the human genome. Replacement of a purine with another purine (A/G) or a pyrimidine with another pyrimidine (C/T) is known as a transition. In contrast,...
01:11Genome-wide Association Studies-GWAS
Genome-wide association studies or GWAS are used to identify whether common SNPs are associated with certain diseases. Suppose specific SNPs are more frequently observed in individuals with a particular disease than those without the disease. In that case, those SNPs are said to be associated with the disease. Chi-square analysis is performed to check the probability of the allele likely to be associated with the disease.
GWAS does not require the identification of the target gene involved in...
GWAS does not require the identification of the target gene involved in...
02:54Evolutionary Relationships through Genome Comparisons
Genome comparison is one of the excellent ways to interpret the evolutionary relationships between organisms. The basic principle of genome comparison is that if two species share a common feature, it is likely encoded by the DNA sequence conserved between both species. The advent of genome sequencing technologies in the late 20th century enabled scientists to understand the concept of conservation of domains between species and helped them to deduce evolutionary relationships across diverse...
02:34DNA Microarrays
Microarrays are high-throughput and relatively inexpensive assays that can be automated to analyze large quantities of data at a time. They are used in genome-wide studies to compare gene or protein expression under two varied conditions, such as healthy and diseased states. Microarrays consist of glass or silica slides on which probe molecules are covalently attached through surface functionalization. Most commonly, the slides are prepared through the chemisorption of silanes to silica...
01:28Human Genetics
Human genetics provides a profound framework for understanding the interplay between genetic predispositions and human psychology. At the heart of this discipline lies the study of how genes influence physical traits, behaviors, and susceptibility to diseases. Each person carries a unique genetic code that subtly or significantly shapes their psychological and behavioral landscape.
The complex relationship between genetics and psychology is observable through common biological components such...
The complex relationship between genetics and psychology is observable through common biological components such...