Inference of recombinational hotspots using gametic disequilibrium values

Area of Science:

• Population genetics
• Molecular evolution

Background:

• Gametic disequilibrium (GD) is used to identify recombination hotspots.
• Common measures of GD, like the correlation coefficient, are sensitive to allele frequencies.
• This frequency dependence can lead to misinterpretations in genetic studies.

Purpose of the Study:

• To evaluate the impact of allelic frequencies on measures of gametic disequilibrium.
• To highlight potential misinterpretations arising from frequency-dependent GD measures.
• To demonstrate the utility of frequency-independent measures, such as Lewontin's normalized disequilibrium.

Main Methods:

• Analysis of gametic disequilibrium measures.
• Comparison of frequency-dependent (correlation coefficient) and frequency-independent (Lewontin's normalized disequilibrium) metrics.
• Application of these measures to data from the beta-globin gene cluster.

Main Results:

• The correlation coefficient is significantly influenced by allelic frequencies.
• Lewontin's normalized disequilibrium measure provides a more robust assessment, independent of allele frequencies.
• Illustrative data from the beta-globin gene cluster demonstrate potential misinterpretations with frequency-dependent measures.

Conclusions:

• Allele frequency must be considered when interpreting gametic disequilibrium.
• Frequency-independent measures are crucial for accurately inferring recombination hotspots.
• The beta-globin gene cluster serves as a case study for these genetic analysis principles.