Genetic Variation in Bacteria

Different methods, such as horizontal gene transfer, induced mutations, and spontaneous mutations, can result in genetic variation in bacteria. A brief description of these processes is provided below:

Spontaneous Mutation

During DNA replication, spontaneous mutations are unintentional modifications to the DNA sequence.

• Errors in the replication of DNA, DNA repair procedures, or exposure to chemicals or radiation from the environment can all cause these mutations.
• Genetic diversity is gradually increased throughout time by spontaneous mutations.

Induced Muatation

When external causes, including exposure to mutagenic chemicals, affect the DNA sequence, it is referred to as an induced mutation.

• Radiation (such as UV light), certain chemicals, and physical factors that speed up mutations are examples of mutagenic agents.
• Gene function may be studied in the lab using induced mutations, or strains with desired characteristics can be produced.

Horizontal Gene Transfer

Genetic material can be transferred across different species or persons within the same generation through a process known as horizontal gene transfer. Because HGT enables the quick exchange of genetic information, it has a major impact on the evolution of bacteria. The three primary processes of horizontal gene transfer in bacteria are: Transformation, transduction, and conjugation.

Bacterial Genetic Transformation

Bacteria are able to pick up free DNA from their surroundings and integrate it into their genomes during transformation. Particular proteins that can bind and transfer extracellular DNA into the cell are present on the surface of bacteria, which helps to facilitate this process.

Bacterial Genetic Transduction

Genetic material is transferred from one bacterium to another by bacteriophages, which are viruses that infect bacteria. This process is known as transduction. A bacteriophage delivers genetic material to another bacterium by infecting it and incorporating the bacterial DNA into its viral genome during the transduction process. It is of two types: Generalized Transduction and Specilized Transduction.

Generalized Transduction

Generalized transduction is the process by which a bacteriophage transfers any type of bacterial DNA, including plasmid and chromosomal DNA, from a donor bacterium to a recipient bacterium during the viral life cycle.

• During the production of new phage particles, a bacteriophage may accidentally package bacterial DNA rather than its own viral DNA, leading to this sort of transduction.
• After the donor bacteria is lysed, the resultant transducing particle a phage containing bacterial DNA is subsequently released.
• This transducing particle has the ability to introduce bacterial DNA into the cytoplasm of another bacterium it infects. Genetic exchange may result from the transmitted DNA recombining with the receiving bacterium’s chromosome.

Specilized Transduction

Only particular genes from the bacterial chromosome are passed on during specialized transduction, a more focused type of transduction.

• During lysogeny, a latent phase of the viral life cycle, a temperate bacteriophage incorporates its DNA into the bacterial chromosome as a prophage.
• Sometimes the prophage excises uncontrollably, removing neighboring bacterial genes in the process.
• The phage can contain both its own DNA and the bacterial genes that were inadvertently deleted when it multiplies and enters the lytic cycle.
• When a phage infects a new bacterium, it injects the recipient bacterium with both its own DNA and the bacterial genes. Following integration, the recipient chromosome and the integrated bacterial genes could recombine.

Bacterial Genetic Conjugation

Conjugation is the process by which genetic material is directly transferred from one bacteria to another by physical contact. Usually, a conjugative plasmid carrying the genes required for the transfer process is used in the transfer. Genetic material may be transferred between the donor and recipient bacteria by the formation of a pilus, a tiny attachment resembling hair, which allows for physical contact.

Also Read: Difference Between Lytic and Lysogenic Cycle

Bacterial Genetics is the study that focuses on the transmission of genetic information, both within and between interbreeding lines of bacteria, as well as the expression of genetic information and how genotype (or genetic information) influences phenotype (or the physiology) of the bacterium. There are three methods of DNA transfer in bacteria: Bacterial conjugation, Natural transformation, and Transduction. In this article, we will learn about bacterial genetics, its type, and importance.