Gene Conversion Article Index for
Gene
Website Links For
Gene
 

Information About

Gene Conversion




Gene conversion is a phenomenon which occurs during Meiotic division. It is a process by which DNA sequence information is transferred from one DNA helix (which remains unchanged) to another DNA helix, whose sequence is altered. It occurs occasionally during general Recombination .

Meiosis is the cell division step that produces the . The strands then segregate, over two cell division steps, into four Haploid daughter cells - with half the amount of genetic material each as the original mother cell.

If you have a gene at which an organism inherited different copies from each of its parents, it is called heterozygous: generically represented as genotype: Aa (i.e. one copy of variant ( Allele ) 'A', and one copy of allele 'a'). When a heterozygote creates gametes, the alleles should split, and end up in a 1:1 ratio in the resulting cells. However, gene conversion refers to an error during meiosis, in which a ratio other than the expected 1A:1a is observed - for example 3A:1a, 1A:3a, 5A:3a or 3A:5a.

This conversion of one allele to the other is due to inappropriate base mismatch repair during recombination: if one of the four strands during meiosis pairs up with one of the four strands of a different Chromosome , as can occur if there is sequence Homology , mismatch repair can alter the sequence of one of the chromosomes, to match identically that on the other.

Also is one of the ways a gene may be mutated to create a cancerous gene.