recombinant

Recombinant describes genetic material or organisms that contain DNA from two or more sources. In molecular biology, recombinant DNA refers to DNA fragments that have been joined together artificially, producing sequences that do not occur as a single natural molecule in any one organism. A recombinant organism carries this recombinant DNA in its genome or as a plasmid or viral vector.

Natural recombination is a biological process that shuffles genetic material during reproduction and replication. In meiosis, homologous recombination and crossing over create new allele combinations, increasing genetic diversity. Bacteria and some viruses also exchange DNA by recombination through mechanisms such as transformation, transduction, and conjugation, while non-homologous end joining can join fragments from different sources in cells.

Recombinant DNA technology uses enzymes such as restriction enzymes and DNA ligase to cut and paste DNA. Fragments are inserted into vectors such as plasmids or viral genomes and introduced into host cells, which replicate the DNA and express the encoded genes. This allows production of recombinant proteins and the study of gene function.

Applications include therapeutic proteins such as insulin and monoclonal antibodies, vaccines, diagnostic enzymes, and industrial enzymes. Recombinant organisms are used to improve crops, produce biofuels, and serve as research tools. Gene therapy and genome editing rely on recombinant methods to insert, delete, or replace genetic material.

Safety and regulation: Recombinant DNA techniques are subject to biosafety guidelines and regulatory oversight to minimize risks of unintended effects, horizontal gene transfer, or ecological impact. Ethical concerns focus on consent, long-term consequences, and access to benefits. See also recombinant DNA technology, homologous recombination, site-specific recombination.