Genomic DNA k-mer spectra: models and modalities

Area of Science:

• Genomics
• Bioinformatics
• Computational Biology

Background:

• DNA k-mer frequencies offer insights into genomic complexity.
• Large-scale genomic data enables analysis of longer k-mers.

Purpose of the Study:

• Investigate k-mer spectra across diverse species.
• Explain observed spectral modalities using probabilistic models.

Main Methods:

• Analyzed k-mer spectra of over 100 species (Archea, Bacteria, Eukaryota).
• Applied low-order Markov models to explain spectral properties.

Main Results:

• Most species show unimodal k-mer spectra.
• Mammals and tetrapods exhibit multimodal spectra.
• Low-order Markov models partially explain spectral modalities.

Conclusions:

• Multimodal spectra correlate with specific C+G content and CpG suppression ranges, characteristic of tetrapods.
• Other genomes with CpG suppression, like Entamoeba histolytica, lack multimodal spectra.
• Human genome functional elements display modality dependent on these genomic features.