(jeh-NOH-mik in-stuh-BIH-lih-tee) The increased tendency for DNA mutations (changes) and other genetic changes to occur during cell division. Genomic instability is caused by defects in certain processes that control the way cells divide.
What causes genome instability?
Changes that occur during DNA repair, chromosome duplication, and transmission or via recombination provide a natural source of genetic variation. They occur at low frequency because of the intrinsic variable nature of genomes, which we refer to as genome instability.
What is genome instability and mutation?
Genome instability (also genetic instability or genomic instability) refers to a high frequency of mutations within the genome of a cellular lineage. These mutations can include changes in nucleic acid sequences, chromosomal rearrangements or aneuploidy. Genome instability does occur in bacteria.
How is genomic instability detected?
Commonly used markers of mitochondrial genome instability detected by PCR and followed by direct sequencing include point mutations, insertions, deletions, and length changes in homopolymeric or dimeric nucleotide tracts.
How does genetic instability cause cancer?
In summary, CIN and aneuploidy could together create a state in which cancer cells not only continuously lose and gain whole chromosomes, but also acquire new mutations and translocations, which interfere with the function of genes involved in DNA repair, mitotic fidelity and cell cycle progression, thereby promoting …
Why is genomic instability important?
The genomic instability provides individuals a shorter cell cycle and/or an advantage of bypassing intracellular and immunological control systems, thereby give cancerous cells a growth advantage and being selected as malignantly transformed cells.
How does genomic instability affect bacteria?
Genome instability is also used by pathogenic bacteria to facilitate host infection without being attacked by immune systems. Some instabilities are programmed, whereas others are random. They can be the result of specialized genetic elements and/or of the action of endogenous pathways of DNA metabolism.
What is a microsatellite instability?
Listen to pronunciation. (MY-kroh-SA-teh-lite in-stuh-BIH-lih-tee) A change that occurs in certain cells (such as cancer cells) in which the number of repeated DNA bases in a microsatellite (a short, repeated sequence of DNA) is different from what it was when the microsatellite was inherited.
How is chromosomal instability measured?
The number of fluorescent foci present within a cell can be used as a surrogate marker for chromosome copy numbers, and this can be monitored through multiple rounds of cell division. Thus, both population heterogeneity and the temporal dynamics of copy number gains or losses can be quantified to evaluate N-CIN.
What is a genomic scar?
A genomic scar can be defined as a genomic aberration with a known origin. Recent attempts at developing an assay that acknowledges the different means by which defects in HR may occur besides BRCA1/2 dysfunction have centered around the measurement of such scars (Table 1) [29,33-35].