høyGC

høyGC is a term used to describe regions of DNA with high guanine–cytosine content, or GC-rich regions. GC content is the percentage of nucleotides that are guanine or cytosine in a sequence. Because G–C base pairs form three hydrogen bonds, GC-rich DNA is more thermally stable and has a higher melting temperature than AT-rich DNA.

GC content varies widely among organisms and across genomes. Bacterial GC content ranges roughly from 25% to over 70%; many eukaryotic genomes average around 40–50%. GC-rich regions often associate with regulatory elements and higher gene density in some species; CpG islands near promoters are typically GC-rich and are subject to methylation, influencing gene regulation.

High GC content poses technical challenges for sequencing and amplification. GC-rich regions can exhibit poor coverage, biases in PCR, and difficulties in genome assembly. Mitigation strategies include PCR-free library preparation, alternative sequencing chemistries, and targeted enrichment.

Analyses of høyGC commonly use sliding-window calculations of GC percentage, GC skew, and isochore or domain analyses to study genome structure, evolution, and regulatory landscapes. Such analysis helps in understanding genome organization and facilitating comparative genomics.

In biology and medicine, høyGC content influences DNA stability, chromatin organization, and gene regulation. The concept aids in explaining variation in genome architecture and informs experimental design in sequencing and annotation projects.