The genetic recombination (or gene) refers to exchange genes between two nucleic acid molecules, to form new combinations of genes on a chromosome .If two chromosomes break and come together again, some genes carried by these chromosomes are exchanged, a process called crossing over.The original chromosomes recombine, so that each now carries a part of the genes of the other.
Types of Gene Recombination
Gene recombination can be homologous or non-homologous:
- Homologous gene recombination : occurs between identical or very similar DNA sequences. That is, between homologous sequences.
- Non-homologous gene recombination : occurs between DNA sequences without any similarity to each other.
Gene Recombination and Mutation
Gene recombination and mutation are different processes.
However, both processes are involved with the genetic variability of individuals .
The mutation corresponds to inherited changes in the DNA sequence. It is the primary source of variability.
Gene recombination is the mixing of genes between individuals of the same species. It increases the variability primarily produced by the mutation.
Thus, it can be said that mutation and recombination work together. Meanwhile, the mutation modifies DNA. Recombination promotes mixing between the modified genes between two individuals.
Gene Recombination and Evolution
The modern theory of evolution (Neodarwinism) considers three main factors in the evolutionary process: gene mutation, gene recombination and natural selection .
Mutation and gene recombination are responsible for genetic variability , ensuring that individuals are genetically different each generation.
Without the processes of genetic variability, such as gene recombination and mutation, evolution would be extremely slow. This is because, there would be no mechanisms to bring together the mutations of different individuals.
It is through genetic variability that organisms evolve and adapt to the environment.
Bacterial Genetic Recombination
acteria are microorganisms with a high capacity to reproduce, basically presenting asexual reproduction as a process of formation of new individuals. Because of this ability to reproduce in a few minutes, a single bacterium can give rise to a population of bacteria similar to the original. This set of bacteria caused by an “original” is known as a clone.
However, even without sexual reproduction, in certain species processes occur in which the mixture of genetic material allows the formation of different bacteria. These processes are known as genetic recombination in bacteria and can occur in 3 basic ways: transformation, transduction and conjugation.