Gene conversion

Gene conversion is a molecular biological process where one DNA sequence replaces a homologous sequence such that the sequences become identical after the conversion event. Gene conversion can be either allelic, or ectopic:

• Allelic gene conversion occurs between two alleles of the same gene, which are located at the same locus on homologous chromosomes.
• Ectopic gene conversion occurs between sequences that are similar but not alleles. They are located at different loci on the same or on different chromosomes.

Mechanism

Gene conversion occurs during meiosis, the process that generates gametes for sexual reproduction. It begins when a double-strand break occurs in one of the two DNA molecules. The broken DNA molecule uses the intact homologous DNA sequence as a template to repair the break. This process is called homologous recombination.

Consequences

Gene conversion can have significant effects on genetic diversity. It can increase the frequency of a beneficial allele in a population, and it can also contribute to the maintenance of harmful alleles. Gene conversion can also lead to the evolution of new genes.

See also

• Genetic recombination
• Homologous recombination
• Meiosis
• Molecular biology

References

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  Gene conversion
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  Gene conversion