mutagenez

Mutagenesis (French: mutagénèse) is the process by which the genetic information of an organism is altered, resulting in a genetic variant. In biology, the term covers both spontaneous genetic variation and laboratory-induced mutations used to study gene function and biology.

Mutagenesis can occur spontaneously or be induced in the laboratory. Induced mutagenesis uses mutagens—agents that increase the mutation rate. Mutagens are chemical (for example alkylating agents such as EMS, nitrosamines, base analogs), physical (UV or ionizing radiation such as X-rays and gamma rays), or, in some contexts, biological (certain transposons or viruses that disrupt genes).

Mutations arise through DNA damage or misreplication. Outcomes include base substitutions, insertions, deletions, and chromosomal rearrangements. The spectrum of mutations depends on the mutagen and the organism’s DNA repair systems, which influence error types and mutation hotspots during replication or repair.

Methods and approaches include forward genetics (screening organisms for interesting phenotypes to identify corresponding genes) and reverse genetics (testing the effect of specific gene changes). Laboratory techniques span chemical mutagenesis, transposon mutagenesis, and, in modern contexts, targeted mutagenesis and genome editing methods such as CRISPR/Cas9. Techniques like site-directed or saturation mutagenesis enable precise or comprehensive alteration of DNA sequences.

Applications of mutagenesis encompass functional genomics, model organism research, strain improvement in agriculture and industry, and protein engineering. It also provides insight into mutational processes and disease mechanisms, including cancer, by linking DNA damage to phenotypic outcomes.

Safety and ethics: mutagenesis experiments are conducted under appropriate biosafety guidelines and regulatory oversight to minimize risks to researchers and the environment.