Gene conversion is a nonreciprocal transfer of genetic information. The
following figure illustrates the difference between gene conversion and DNA
crossover. An origin of gene
conversion is explanined in Figure 8-D-5.
Figure 8-D-4. Comparison between gene
conversion and DNA crossover. (a) Two DNA molecules. (b) Gene
conversion - the red DNA donates part of its
genetic information (e-e' region) to the blue DNA. (c) DNA
crossover - the two DNAs exchange part of their
genetic information (f-f' and F-F').
Figure 8-D-5. An origin of gene
conversion. (a) Heteroduplexes formed by the resolution
of Holliday structure or by other mechanisms. (b) The blue DNA
uses the invaded segment (e') as template to "correct" the mismatch,
resulting in gene conversion. (c) Both DNA molecules use their
original sequences as template to correct the mismatch. Gene conversion
does not occur.