Related Experiment Videos
Genomic regions exhibiting positive selection identified from dense genotype data
Christopher S Carlson1, Daryl J Thomas, Michael A Eberle
1Department of Genome Sciences, University of Washington, Seattle, Washington 98195-7730, USA. csc47@u.washington.edu
Genome Research
|October 28, 2005
Summary
Researchers identified specific DNA regions showing signs of recent natural selection across human populations. These findings highlight potential evolutionary pressures shaping the human genome and offer targets for further investigation.
Area of Science:
- Population Genetics
- Evolutionary Biology
- Genomics
Background:
- The allele frequency spectrum of DNA polymorphisms can reveal natural selection signatures deviating from neutral theory.
- Tajima's D is a statistical test used to detect such deviations.
Purpose of the Study:
- To identify genomic regions under recent, strong selective sweeps using Tajima's D.
- To compare patterns of selection across different human populations.
Main Methods:
- Validated Tajima's D statistic correlation between full resequencing and genome-wide genotyping data.
- Performed a sliding window analysis of Tajima's D across the human genome.
- Identified Contiguous Regions of Tajima's D Reduction (CRTRs) in African, European, and Chinese descent populations.
- Conducted full resequencing of genes within identified CRTRs.
Main Results:
- A significant correlation (P = 0.001) was found for Tajima's D between different data types.
- Numerous CRTRs were identified: 7 in African-descent, 23 in European-descent, and 29 in Chinese-descent populations.
- Limited overlap of CRTRs was observed between populations, suggesting population-specific selection.
- Genes within CRTRs showed frequency spectra inconsistent with neutral evolution.
Conclusions:
- The study successfully identified genomic regions likely shaped by recent selective sweeps.
- Population-specific CRTRs indicate diverse evolutionary pressures across human groups.
- Further research into functional polymorphisms within CRTRs can illuminate recent human adaptation.