Transversions have larger regulatory effects than transitions

Area of Science:

• Genomics
• Molecular Biology
• Evolutionary Biology

Background:

• Transversions (Tv's) and transitions (Ts's) are two types of point mutations with differing effects on protein sequences.
• The impact of Tv's and Ts's on non-protein-coding sequences, particularly gene regulation, is largely unknown.
• Genetic variants can affect gene expression by altering transcription factor (TF) binding sites.

Purpose of the Study:

• To investigate whether transversions have a greater impact than transitions on TF binding and gene expression.
• To explore the role of mutation type in regulatory DNA variation.

Main Methods:

• Analysis of TF binding motifs and allele-specific TF binding data.
• Massively parallel population-scale reporter assays to measure the activity of human gene regulatory elements.
• Comparative analysis of Tv and Ts impacts on DNA-binding protein interactions.

Main Results:

• Tv's were found to have larger impacts on regulatory DNA compared to Ts's.
• A depletion of Tv's was observed within TF binding motifs and TF binding sites.
• Reporter assays confirmed that Tv's significantly affect the activity of human gene regulatory elements.

Conclusions:

• Tv's are more likely to disrupt TF binding, leading to greater changes in gene expression.
• These findings highlight a novel property of regulatory variation with implications for understanding complex traits and diseases.
• Understanding functional non-coding variation is crucial for future genetic studies.