Book contents
- Frontmatter
- Contents
- List of Contributors
- PART 1 Basic Mechanisms of Genome Rearrangement in Bacteria
- 1 Mechanisms of homologous recombination in bacteria
- 2 Introduction to site-specific recombination
- 3 Site-specific recombination by the serine recombinases
- 4 Mobile introns and retroelements in bacteria
- PART 2 Horizontal Gene Transfer and Genome Plasticity
- PART 3 Biological Consequences of the Mobile Genome
- Index
- Plate Section
- References
2 - Introduction to site-specific recombination
Published online by Cambridge University Press: 06 August 2009
- Frontmatter
- Contents
- List of Contributors
- PART 1 Basic Mechanisms of Genome Rearrangement in Bacteria
- 1 Mechanisms of homologous recombination in bacteria
- 2 Introduction to site-specific recombination
- 3 Site-specific recombination by the serine recombinases
- 4 Mobile introns and retroelements in bacteria
- PART 2 Horizontal Gene Transfer and Genome Plasticity
- PART 3 Biological Consequences of the Mobile Genome
- Index
- Plate Section
- References
Summary
Recombination provides a means for creating genetic variety. Exchange of information within gene pools expands their diversity and enhances the choices available for natural selection to act on. Recombination can be broadly divided into two classes: the highly pervasive “homologous” recombination and the more specialized “site-specific recombination.”
HOMOLOGOUS RECOMBINATION
Before we discuss site-specific recombination, a brief overview of general (or homologous) recombination is useful for an appreciation of the distinctions between the two systems. Homologous recombination is a nearly universal mechanism employed by living organisms to reshuffle their genetic information. Within a cell, recombination can occur between two homologous chromosomes, between two sister chromatids formed by DNA replication, and between extrachromosomal elements such as plasmids or viral genomes. In eukaryotes, the rate of recombination during mitosis is relatively low and is markedly increased during meiosis. In fact, genetic exchange between homologs and chiasma formation appear to be a prerequisite for the proper reductional segregation of chromosomes and the generation of haploid gametes. The consequences of the resulting genetic configuration and the corresponding fitness contribution to an individual will be manifested directly, and almost immediately, in a haploid organism. For a diploid organism, the expression of the novel genetic makeup must await the fusion between the male and female gametes to produce a zygote. Recombination is therefore one of the forces that drive Darwinian evolution.
- Type
- Chapter
- Information
- The Dynamic Bacterial Genome , pp. 33 - 82Publisher: Cambridge University PressPrint publication year: 2005
References
- 4
- Cited by