klón

A klón is an organism, cell, or DNA fragment that is genetically identical to the donor from which it was derived. In biology, clones can arise naturally, for example through asexual reproduction or the formation of identical twins, or they can be produced artificially through cloning techniques. While clones share the same nuclear genome, epigenetic differences and environmental factors can introduce variation.

Cloning methods are typically categorized into molecular cloning, reproductive cloning, and therapeutic cloning. Molecular cloning involves creating copies of DNA fragments for research and biotechnology. Reproductive cloning aims to generate an entire organism with the same genome as the donor, usually via somatic cell nuclear transfer or related technologies. Therapeutic cloning seeks to produce embryonic stem cells that are genetically matched to a donor for medical treatment, rather than to create a whole organism.

Applications of cloning span science, medicine, and agriculture. Molecular cloning is foundational to genetic research, gene therapy development, and industrial biotechnology. Reproductive cloning has been used to reproduce animals with desirable traits or model species for study, though efficiency is often low and welfare concerns arise. Therapeutic cloning holds potential for personalized regenerative medicine. Ethical, legal, and social issues are central to cloning debates, including animal welfare, risks to health, genetic diversity, and the implications of human cloning, which is heavily regulated or prohibited in many jurisdictions.

Historically, natural clones such as identical twins preceded laboratory techniques. The first mammal cloned from an adult cell, Dolly the sheep, was reported in 1996 and announced in 1997 by researchers at the Roslin Institute. Since then, cloning has progressed but remains controversial and technically challenging, with many applications focusing on research and biotechnology rather than the creation of new individuals.