PolyaPeak

PolyaPeak is a software tool designed to improve the detection of transcription factor binding sites (TFBSs) by incorporating peak shape information. TFBSs are crucial regulatory elements in genetic transcription, and their accurate detection is essential to understanding gene regulation. ChIP-seq is a widely used method for identifying TFBSs, where sequence reads aligned to the forward and reverse strands of the reference genome form two separate peaks around each binding site. However, accurately identifying the true binding site between these two peaks can be challenging.

PolyaPeak addresses this challenge by modeling the peak shapes using a flexible Pólya model, which is automatically learned from data using the Minorization-Maximization algorithm. The resulting shapes are then integrated with read count information via a hierarchical model to distinguish true binding sites from background noises. This approach enables PolyaPeak to robustly improve TFBS detection compared to existing methods.

The software tool is freely available as an R package, and its effectiveness has been demonstrated in extensive real data analysis. By leveraging peak shape information, PolyaPeak provides an efficient method for accurately detecting TFBSs.