However, it should be recognized that recombination covers a much wider spectrum of events including, (i) crossing over, both meiotic and mitotic (reciprocal exchange of segments), (ii) gene conversion (non- reciprocal events), (iii) exchange between sister chromatids (even though this does not lead to a change in genotype), (iv) repair of DNA damage, etc. For the purpose of this section, in the treatment of recombination, we have excluded processes, in which different DNA sequences are simply ligated together to produce, what is commonly called recombination DNA.
The recombinant DNA and gene cloning will be separately discussed in Genetic Engineering and Biotechnology 1. Recombinant DNA and PCR (Cloning and Amplification of DNA)
. As earlier discussed in Linkage and Crossing Over in Diploid Organisms (Higher Eukaryotes)
, the mechanism of genetic recombination is mainly based on breakage and reunion process, which has been demonstrated experimentally both at the level of chromosomes as well as at the level of DNA molecules (Linkage and Crossing Over in Diploid Organisms (Higher Eukaryotes)