On the origins of genetic variants.
Two contrasting mechanisms responsible for the creation of genetic variants are described: one is the manifestation of the limited accuracy of the cellular machinery for DNA replication, the other results from the ability of cells to repair damaged DNA. Replication-dependent variants and those caused by episodical DNA damage enhance the probability that a small fraction of a cell population may survive a sudden (physical or biological) change of environmental conditions. Replication-independent variants arise during persistent but not immediately lethal stress (e.g. starvation) of a non-dividing population. The variants observed under these conditions are of selective advantage because they are able to cope with the particular stress situation. The molecular basis of their creation is a matter of intensive debate.
Wintersberger
U
U
Department of Molecular Genetics, University of Vienna, Austria.
D005075:Biological Evolution; D004249:DNA Damage; D004260:DNA Repair; D004261:DNA Replication; D004926:Escherichia coli / Q000235:genetics; D014644:Genetic Variation; D009154:Mutation; D012641:Selection, Genetic