Question

Describe what a CG island is, where it is found, and how it controls gene expression

Answer 1

CG islands are parts of DNA are usually found in the promoter region, they are not very common as these become methylated due to mutation.

They are typically located in the 5' end of genes and act as gene markers.CG islands are associated with genes indicating that they help in locating and regulating genes within DNA sequences.

DNA methylation has been a subject of great interest in recent years as it affect the gene expression mainly because of the presence of CG islands. Targeted methylation at CG islands is important is determinig the mechanism that governs the activation of chromosomes and also in determining specific expression patterns of genes in different cells.