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CLONE definition: 1. a plant or animal that has the same genes as the original from which it was produced 2. someone…. Learn more.
Dec 1, 2023 · Learn how to create an exact copy of your data on a new drive using free tools for Windows and macOS. Follow the step-by-step instructions for DiskGenius and SuperDuper! to clone your drive.
- Overview
- Early cloning experiments
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Cloning is the process of generating a genetically identical copy of a cell or an organism. Cloning happens all the time in nature. In biomedical research, cloning is broadly defined to mean the duplication of any kind of biological material for scientific study, such as a piece of DNA or an individual cell.
Why is cloning important?
Therapeutic cloning enables the cultivation of stem cells that are genetically identical to a patient. This approach, by avoiding risk of rejection by the immune system, has the potential to benefit many patients, including those affected by Alzheimer disease, diabetes, and spinal cord injury.
Why is cloning controversial?
The cloning of humans remains universally condemned, primarily for the associated psychological, social, and physiological risks. There are also concerns that cloning promotes eugenics, the idea that humanity could be improved through the selection of individuals possessing desired traits. There also exists controversy over the ethics of therapeutic and research cloning, which makes use of embryos that are otherwise discarded.
cloning, the process of generating a genetically identical copy of a cell or an organism. Cloning happens often in nature—for example, when a cell replicates itself asexually without any genetic alteration or recombination. Prokaryotic organisms (organisms lacking a cell nucleus) such as bacteria create genetically identical duplicates of themselves using binary fission or budding. In eukaryotic organisms (organisms possessing a cell nucleus) such as humans, all the cells that undergo mitosis, such as skin cells and cells lining the gastrointestinal tract, are clones; the only exceptions are gametes (eggs and sperm), which undergo meiosis and genetic recombination.
Reproductive cloning was originally carried out by artificial “twinning,” or embryo splitting, which was first performed on a salamander embryo in the early 1900s by German embryologist Hans Spemann. Later, Spemann, who was awarded the Nobel Prize for Physiology or Medicine (1935) for his research on embryonic development, theorized about another cloning procedure known as nuclear transfer. This procedure was performed in 1952 by American scientists Robert W. Briggs and Thomas J. King, who used DNA from embryonic cells of the frog Rana pipiens to generate cloned tadpoles. In 1958 British biologist John Bertrand Gurdon successfully carried out nuclear transfer using DNA from adult intestinal cells of African clawed frogs (Xenopus laevis). Gurdon was awarded a share of the 2012 Nobel Prize in Physiology or Medicine for this breakthrough.
Advancements in the field of molecular biology led to the development of techniques that allowed scientists to manipulate cells and to detect chemical markers that signal changes within cells. With the advent of recombinant DNA technology in the 1970s, it became possible for scientists to create transgenic clones—clones with genomes containing pieces of DNA from other organisms. Beginning in the 1980s mammals such as sheep were cloned from early and partially differentiated embryonic cells. In 1996 British developmental biologist Ian Wilmut generated a cloned sheep, named Dolly, by means of nuclear transfer involving an enucleated embryo and a differentiated cell nucleus. This technique, which was later refined and became known as somatic cell nuclear transfer (SCNT), represented an extraordinary advance in the science of cloning, because it resulted in the creation of a genetically identical clone of an already grown sheep. It also indicated that it was possible for the DNA in differentiated somatic (body) cells to revert to an undifferentiated embryonic stage, thereby reestablishing pluripotency—the potential of an embryonic cell to grow into any one of the numerous different types of mature body cells that make up a complete organism. The realization that the DNA of somatic cells could be reprogrammed to a pluripotent state significantly impacted research into therapeutic cloning and the development of stem cell therapies.
Cloning is the generation of a genetically identical copy of a cell or an organism. Learn about the history, methods, and applications of cloning in biomedical research, agriculture, and conservation.
- Michael Rugnetta
The term clone is used in horticulture to refer to descendants of a single plant which were produced by vegetative reproduction or apomixis. Many horticultural plant cultivars are clones, having been derived from a single individual, multiplied by some process other than sexual reproduction. [22]
Learn the meaning of clone as a noun and a verb, with synonyms, examples, and word history. Find out how cloning works in plants, animals, and DNA.
Nov 17, 2021 · In humans, every cell in the body is a clone of the first embryo cell created when the father's sperm fertilized the mother's egg, and identical twins are natural clones.
May 9, 2022 · Select the drive to clone; Select a cloning destination drive; Select partitions; Save your configuration; Clone; Read on for detailed instructions regarding each step.
