How Does Clone Genetics Impact Biology and Modern Science?
Cloning is the process of manufacturing individuals with identical or virtually identical DNA, either naturally or artificially. Naturally, the clones are produced by many organisms through agamogenesis. Cloning in biotechnology refers to the method of making clones of organisms or copies of cells or DNA fragments.
Define Clone in Biology
The term clone, coined by Herbert J. Webber, springs from the traditional Greek word “κλών klōn”, which means "twig". In botany, the term lusus was traditionally used. In horticulture, the spelling clon was used until the 20th century; the last word ‘e’ came into use to point the vowel as a "long o" rather than a "short o". Since the term entered the favoured lexicon during a more general context, the spelling clone has been used exclusively.
Clone, also spelt clon, cell, or organism that's genetically just like the first cell or organism from which it's derived. The word clone originates from the traditional Greek klon, meaning “twig.”
A clone is a group of individuals obtained through progeny or asexual reproduction from a single parent.
Types of Artificial Cloning
There are three different kinds of artificial cloning: Gene cloning produces copies of genes or segments of DNA. Reproductive cloning produces copies of whole animals. Therapeutic cloning produces embryonic stem cells for experiments aimed toward creating tissues to exchange injured or diseased tissues.
1. Gene Cloning: Gene cloning also referred to as DNA cloning, maybe a very different process from reproductive and biomedical cloning. Reproductive and biomedical cloning share many equivalent techniques but are finished with different purposes. Gene cloning is the scientific word for cloning of the genes, where this scientific word indicates, production of a copy of genes or DNA.
2. Reproductive Cloning: In cloning, researchers remove a mature vegetative cell, like a somatic cell, from an animal that they want to repeat. They then transfer the DNA of the donor animal's vegetative cell into an ovum, or oocyte, that has had its DNA-containing nucleus removed.
Researchers can add the DNA from the vegetative cell to the empty egg in two alternative ways. In the first method, they remove the DNA-containing nucleus of the vegetative cell with a needle and inject it into the empty egg. In the second approach, they use an electrical current to fuse the whole vegetative cell with the empty egg. In both processes, the egg is allowed to become an early-stage embryo within the test-tube then is implanted into the womb of a woman animal.
Ultimately, the woman gives birth to an animal that has an equivalent genetic structure because of the animal that donated the vegetative cell. This young animal is mentioned as a clone. Reproductive cloning may require the utilization of a mother to permit the development of the cloned embryo, as was the case for the foremost famous cloned organism, Dolly the sheep.
3. Therapeutic Cloning: Therapeutic cloning involves creating a cloned embryo for the only purpose of manufacturing embryonic stem cells with an equivalent DNA because of the donor cell. These stem cells are often utilized in experiments aimed toward understanding disease and developing new treatments for disease. To date, there's no evidence that human embryos are produced for biomedical cloning.
The richest source of embryonic stem cells is tissue formed during the primary five days after the egg has begun to divide. At this stage of development, called the blastocyst, the embryo consists of a cluster of about 100 cells which will become any cell type. Stem cells are harvested from cloned embryos at this stage of development, resulting in the destruction of the embryo while it is still in the test tube.
Conclusion
Clone genetics helps the livestock breeders to create a genetic copy exactly which helps in the production of healthier breeds. It helps scientists to develop medicines for humans. The cloned animals such as monkeys are used to develop medicine. Cloning is done in various methods that include gene cloning, therapeutic cloning, and reproductive cloning.
FAQs on Clone Genetics Explained: Meaning, Types & Key Examples
1. What is a clone in the context of genetics?
In genetics, a clone is an organism, cell, or a piece of DNA that is genetically identical to its source or parent. Clones are produced through asexual reproduction, meaning they arise from a single parent. This results in offspring that share the exact same set of genes as the parent, for example, in bacteria that divide by binary fission or plants that reproduce vegetatively.
2. What are the main types of artificial cloning used in biotechnology?
There are three primary types of artificial cloning, each with a different goal:
- Gene Cloning: This type creates copies of specific genes or segments of DNA. It is a fundamental technique in molecular biology, used for sequencing genes, producing proteins like insulin, and creating genetically modified organisms.
- Reproductive Cloning: This process creates a whole organism that is genetically identical to another. The most famous example is Dolly the sheep. The primary method used is Somatic Cell Nuclear Transfer (SCNT).
- Therapeutic Cloning: This involves creating cloned embryos for the purpose of producing embryonic stem cells. These cells can be used to grow healthy tissues to replace injured or diseased ones, offering potential treatments for conditions like Parkinson's disease or severe burns.
3. Can you provide some examples of clones, both natural and artificial?
Clones exist both in nature and as a result of laboratory techniques. Natural clones include bacteria (reproducing by binary fission), yeast (reproducing by budding), and identical twins in humans, which originate from a single fertilised egg. Many plants, like strawberries, reproduce asexually to form clones. Artificial clones include Dolly the sheep, the first mammal cloned from an adult cell, and other animals like cats, dogs, and horses that have been cloned using SCNT. Furthermore, cloned genes inserted into bacteria to produce insulin are a key example of gene cloning.
4. How does the process of reproductive cloning actually work?
The most common method for reproductive cloning is Somatic Cell Nuclear Transfer (SCNT). The process involves several key steps: a somatic (body) cell, containing the complete DNA of the organism to be cloned, is taken. An unfertilised egg cell is also taken, and its nucleus is removed. The nucleus from the somatic cell is then transferred into the enucleated egg cell. This reconstructed egg, now containing the DNA of the clone's parent, is stimulated to divide, developing into an embryo. Finally, this embryo is implanted into the uterus of a surrogate mother to develop to term.
5. What is the key difference between reproductive cloning and therapeutic cloning?
The primary difference between reproductive and therapeutic cloning lies in their ultimate goal. The goal of reproductive cloning is to create a complete, living organism that is a genetic copy of another. The cloned embryo is implanted in a surrogate to be born. In contrast, the goal of therapeutic cloning is to harvest valuable embryonic stem cells. The cloned embryo is grown in a lab for a few days, but it is never implanted in a womb. Instead, its stem cells are extracted for medical research and treatment purposes.
6. Why might a cloned animal not be an exact identical copy of its genetic parent?
While a clone has the same nuclear DNA as its parent, it may not be an identical copy due to several factors. Firstly, the mitochondrial DNA, which is inherited from the egg cell donor, is different. Secondly, and more significantly, environmental factors and epigenetic modifications play a huge role in an organism's development and appearance. For instance, the coat pattern of a calico cat is determined by random X-chromosome inactivation in each cell during development, so a cloned cat will have a different pattern from its parent, even with the same genes.
7. What are the major ethical concerns related to human cloning?
The prospect of human cloning raises significant ethical issues. For reproductive cloning, concerns include the potential for psychological harm to the clone, a decrease in human genetic diversity, and complex questions about identity and individuality. For therapeutic cloning, the primary ethical debate surrounds the creation and destruction of a human embryo to harvest stem cells. Opponents argue that this is morally wrong as it involves destroying potential human life, while proponents highlight its potential to cure debilitating diseases and alleviate suffering.
