Models of Unequal Crossing-Over
Smith (1974) as well as Black and Gibson (1974) were the first to show that the diversity of antibody genes and other multigene families may be adequately explained by assuming unequal crossing-overs. They used computer simulation for understanding the process of coincidental evolution. The basic idea is to start from linearly arranged genes, every one of which is represented by a different integer from others so that it is identified as a gene lineage in a later period of simulation (as in the example given in Fig. 1.7) and to find out how gene members become homogeneous through repeated unequal crossing-overs. Thus their simulation treats a single chromosomal line and an unequal crossing-over takes place between the sister-chromatids, i. e. intrachromosomal unequal crossing-over at somatic cell division. In order to simulate interchromosomal unequal crossing-over at meiosis, one needs to treat the whole population and thus an experiment of a much greater scale becomes necessary.
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