Key-string segmentation algorithm and higher-order repeat 16mer (54 copies) in human alpha satellite DNA in...

Area of Science:

• Genomics
• Molecular Biology
• Bioinformatics

Background:

• Alpha satellite DNA and higher-order repeat (HOR) units are crucial components of centromeric regions.
• Understanding the structure and variation of these repetitive elements is essential for chromosome stability and function.

Purpose of the Study:

• To introduce and exemplify a new key-string segmentation algorithm for identifying alpha satellite DNA and HOR units.
• To computationally segment and analyze a specific human alpha satellite DNA sequence (AC017075.8) from chromosome 7.

Main Methods:

• Development and application of a key-string segmentation algorithm.
• Scanning GenBank data for human alpha satellite DNA sequences.
• Computational segmentation of DNA sequences into HOR and non-HOR domains.
• Identification and analysis of monomer variants and structural variations (insertions, deletions).

Main Results:

• The algorithm successfully segmented human alpha satellite DNA sequence AC017075.8 into HOR and non-HOR domains.
• A dominant key-string (GTTTCT) facilitated segmentation into alpha monomers.
• The HOR domain contained 54 tandemly repeated HOR copies, with identified insertions and deletions.
• Monomer variants within HORs showed 20% divergence, while non-HOR variants diverged by 20-40%.

Conclusions:

• The key-string algorithm is effective for segmenting complex repetitive DNA sequences like alpha satellite DNA.
• The analysis revealed significant structural variation and monomer divergence within centromeric repetitive elements.
• This approach provides insights into the organization and evolution of higher-order repeats in the human genome.