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Transduction This is an illustration of the difference between generalized transduction, which is the process of transferring any bacterial gene to a second bacterium through a bacteriophage and specialized transduction, which is the process of moving restricted bacterial genes to a recipient bacterium. While generalized transduction can occur ...
Esther Miriam Zimmer Lederberg (December 18, 1922 – November 11, 2006) was an American microbiologist and a pioneer of bacterial genetics.She discovered the bacterial virus lambda phage and the bacterial fertility factor F, devised the first implementation of replica plating, and furthered the understanding of the transfer of genes between bacteria by specialized transduction.
Bacteriophage Lambda binds to an E. coli cell by means of its J protein in the tail tip. The J protein interacts with the maltose outer membrane porin (the product of the lamB gene) of E. coli, [9] a porin molecule, which is part of the maltose operon. The linear phage genome is injected through the outer membrane.
E. coli is a gram-negative, facultative anaerobe, nonsporulating coliform bacterium. [18] Cells are typically rod-shaped, and are about 2.0 μm long and 0.25–1.0 μm in diameter, with a cell volume of 0.6–0.7 μm 3. [19] [20] [21] E. coli stains gram-negative because its cell wall is composed of a thin peptidoglycan layer and an outer membrane.
It was originally thought that Escherichia coli, a commonly used laboratory organism, was refractory to transformation. However, in 1970, Morton Mandel and Akiko Higa showed that E. coli may be induced to take up DNA from bacteriophage λ without the use of helper phage after treatment with calcium chloride solution. [6]
A prime example concerning the spread of exotoxins is the adaptive evolution of Shiga toxins in E. coli through horizontal gene transfer via transduction with Shigella species of bacteria. [57] Strategies to combat certain bacterial infections by targeting these specific virulence factors and mobile genetic elements have been proposed. [12]
Transduction is associated with viral-mediated vectors transferring DNA material from one bacterium to another within the genome. [18] Bacterial DNA is placed into the bacteriophage genome via bacterial transduction. In bacterial conjugation, DNA is transferred via cell-to-cell communication.
In Escherichia coli, homologous recombination events mediated by RecA can occur during the period after DNA replication when sister loci remain close. RecA can also mediate homology pairing, homologous recombination and DNA break repair between distant sister loci that had segregated to opposite halves of the E. coli cell. [15]