Discover what are INDUCED MUTATIONS

Mutations are all those changes that occur in the sequence or organization of DNA of an organism (genotype). There are many types of mutations and most of them occur by chance, they are called spontaneous mutations. In other situations, changes in DNA are caused by a certain agent. In that case they are called induced mutations.

But, What are induced mutations? What agents can cause them? In this lesson from a PROFESSOR we will review what induced mutations are and what are the main mutagenic agents that can cause them.

Inside of classification of mutations There are different types and one of them is the induced mutation which is any permanent change that occurs in the sequence or organization of the genetic material of a cell due to causes external to that cell. The other mutations, which are called spontaneous or random, are caused by the cell's own functioning. The machinery in charge of copying the DNA of the cell is not perfect and, sometimes, modifications occur (The cell makes a mistake and changes a specific nucleotide for another, leaves a certain sequence without copying, etc.).

Induced mutations are alterations product of different causes. These causes or agents are generally called mutagens. In nature there are many mutagens, which researchers classify into three groups depending on their origin: chemical mutagens (substances capable of modify DNA), physical mutagens (which are usually radiation) and biological mutagens (living beings that are capable of causing a change in the DNA of another cell).

Mutagens are substances that, as we will see below, are usually found normally in nature. Since the beginning of time, all organisms have been affected by mutagens, which are one of the forces of evolution that help us to better adapt to the environment in which we live.

At the same time, our bodies have developed systems to protect us from these mutagens, which can cause disastrous effects such as diseases, pathologies, etc.. With modern life, human contact with these mutagens has been greater and the amount and concentration of mutagens to which we are exposed is also greater. Therefore, it is important to know which agents are capable of changing our genetic code.

Biological mutagens are microorganisms that can modifyr permanently the DNA of a cell that does not belong to it. These microorganisms are capable of entering or injecting certain agents that integrate into the genome of the "occupied" cell. Biological mutagens are usually of two types:

• Transposons. Transposons are autonomous fragments of DNA that are capable of inserting themselves into the genome of another cell. Once inserted into it, they are copied with the cell's DNA sequence. Once copied, the transposons are cut and are able to continue "parasitizing" other cells.
• Virus. One of the best known mutagenic agents is viruses. Like transposons, viruses are capable of "infecting" a cell to insert portions of its genetic material. The virus uses the machinery of the cell to create copies of itself and in some cases (such as rhinoviruses or adenoviruses) is even capable of modifying the expression of the genes of the cell.

Despite their bad press, biological mutagens are a powerful tool in research (especially bacteriophages) and the development of current medicine. Biological mutagens allow us to develop vaccines, antitoxins, sera, or antigens important for the immunity and survival of many people.