Bacterial Recombination,Genetic Constituents,Chromosomes,Episomes,Plasmids,genetic constituents, e.g. chromosomes, episomes, plasmids,genetic constituents, e.g. chromosomes, episomes, plasmids,Transformation,Conjugation,Transduction

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	Bacterial Recombination - Bacteria divide by simple fission, and are usually haploid with multiple copies and types of genetic constituents, e.g. chromosomes, episomes, plasmids, etc. Bacteria do not undergo mitotic or meiotic cycles; hence they do not undergo sexual reproduction process involving gametic union. The genetic recombination events associated with sexual reproduction like segregation, chromosomal exchange, etc. are not integral parts of the life cycle of bacteria. Recombination, however is undoubtedly important in the evolution of eukaryotes, so is it with bacteria. Although they do not undergo sexual reproduction by the fusion of haploid gametes, bacteria and viruses do undergo processes that incorporate genetic material from one cell or virus into another cell or virus forming recombinants. Actually, bacteria have three different methods to gain access to foreign genetic material; transformation, conjugation and transduction.
The most obvious difference between these three processes is the mode of transfer of DNA from one cell to another. Transformation involves the uptake of naked DNA molecules from one bacterium to another. Transduction occurs when bacterial genes are carried from one bacterium to another by a bacteriophage. Conjugation is the process during .which DNA from a donor or male cell is transferred to a recipient or female cell through a specialized sex pilus or conjugation tube. The three modes of recombination in bacteria can be distinguished by two simple criteria sensitivity to the presence of deoxyribonuclease (DNase) and dependence on cell contact. Recombination by conjugation is not sensitive to DNase and requires the contact of donor and recipient cell whereas transformation is sensitive to DNase treatment and requires no contact of donor and recipient cell. Transduction is very peculiar in that it does not require any contact of donor or recipient cell and is not sensitive to DNase treatment.