It basically involves a method for developing a replica of tissue, organ or cell which are inherently similar to each other.it occur in nature- for instance, when some cell replicated itself asexually without chromosomal mutation and linkage. In prokaryotes, bacteria can produce a genetically alike copy of itself with help of binary fission. On other hand, in eukaryotes like in humans all cells such as skin cells, digestive track lining cells go through mitosis thus produce clones, except from the gamete cells that undergo meiosis and genetic recombination.
Types of cloning
There are two main types of cloning
This type of cloning take place through sexual reproduction and do not involve any kind of genetic makeup alteration. For instance, many types of bacteria and human also undergo this process for reproduction. In bacteria clones are produce through binary fission and their genome split into two genomes while in human identical twins is best example in which fertilized egg split and more than one offspring produce. These identical twins have same genetic makeup but different phenotypes from parents.
Replicating genetic material to produce cells or organs having duplicate genetic information term as artificial cloning. The main purpose of this process is to produce the cell, organs or tissues that have desire traits for the research and scientific study purposes.
Somatic cell nuclear transferase
It is a prevailing method. In biomedical research, this is term as replication of any biological substance such as a piece of DNA or a single cell can be duplicated by using PCR. In July 1996, fist artificially cloned mammal DOLLY sheep is cloned with help of novel method named as somatic cell nuclear transferase (SCNT). In this process, firstly genomic information is detached from egg of female then somatic cells are isolated from desire organism which has to be replicated and nucleus cell is injected into host oocyte with micropipette. Then egg, so “fertilized” is stirred to initiate embryonic growth.
Cloning process of DOLLY sheep
There are various types of SCNT cloning such as the:
- Genetic cloning in which copies of gene or DNA fragments is produced.
- Reproductive cloning in which whole animal is replicate. In 1900, German embryologist Hans Spemann firstly reproductive clone a salamander embryo.
- Therapeutic cloning which involve duplication of embryonic stem cell. With help of these cells researchers intend to develop healthy tissue to interchange injured tissues or unhealthy tissue in body.
In biotechnology, this process need a gene of interest, a vector which carry desire gene, host which give suitable environment to desire gene to duplicate, and medium for development of host strain. However, one method which is under spot light due to its ethical debate is generation of replicated embryo specially of those which are human based and genetically duplicate to those from which they are originated, and frequently use of embryo in research, reproductive or in therapeutic methods.
Scientists around globe endure to debate over benefits of this in anticipations of being able to research and study it more comprehensively. According to an estimate more than 30 countries allotted a ban on it that involve human generative replication. But out of them some countries such as China, Sweden, England allows this for some beneficial reasons that does not depend upon human based reproductive replication.
The major benefits involve
In this scientists take minute quantity of desire organ part for development complete new functioning part of tissues and organs for therapeutic purposes. If labs can replicate only those tissues and organ parts which are necessary than it will minimize the ethical and moral problems linked with complete organism cloning. It is also beneficial because there is a number of patients on organ donor waiting list.
For the production of stem cells.
These are used to create, stabilize and respire damage organs and tissues in body. Some researchers are doing work in order to develop stem cells that are similar to recipient. These cells can also helpful in generation of complete organ and for study and understanding disease to create possible treatments.
For growing genetically cloned lab mice for research studies.
A researcher can understand a human disease by experimenting on animal models such as mice. Mostly animal model made engineered by causing disease developing mutations in their genes but this method is very time consuming and errors and trails are needed on number of generation breeders. Cloning can help to overcome this problem by making a transgenic animal model which result in large number of animal models for study.
It may be helpful for bringing back the extinct or angered species.
In theories it may be possible to bring back an extinct or endanger specie. for this scientist need a source of DNA from well preserved extinct animal source and a closely related animal species which act as egg donor and replicated mother.
For cloning a livestock for food.
There is way progress to replicate a livestock for food such as cattle which are main source of milk and meat.
Cloning help sterile couple too have baby.
Infertility problems can also be overcome by using this method. In this process stem cells are isolated from male parent and then it is inserted in egg and subject to develop as an embryo. The resulting offspring have characteristics of both parents.
Disadvantages of cloning
Along with benefits there are some demerits of as well such as
- It is the copying of identical genes that in result leads to minimize diversity of genes?
- As human clones are alike they all are potential risk of getting infected with same pathogen this will result in great disaster.
- Another disadvantage of cloning is in-breeding, as all have same genotype and reproducing among themselves will cause extinction at end.
Therapeutic cloning involves methods used to isolate stem cell for research study and also for recovery of degenerative disorders in future. Stem cells are cell which through differentiation method generate different specialized cells that may be totipotent to multipotent. stems cells used in therapeutic cloning purpose are embryonic, bone, blood, skin and umbral cord cells. The process involve is enucleation of one cell and inoculation of somatic nucleus in that cell. After this inoculation in vitro reproduction of cell is initiate to isolate stem cells with desire traits of somatic cells that are further used for therapeutic purposes
Cloning possible uses in therapeutics
it can be helpful in deteriorating disorders such as in DIABETES TYPE 1 or in future may be able to cure the degenerative mental disorders such as Alzimher and Parkinson diseases.
Diabetes type 1
It is an autoimmune disorder that is triggered by fabrication of antibodies, which attach on insulin generating pancreases. The deficiency of this hormone that regulate production of glucose in our blood is result of this sugar in our blood for nutrition are not assemble and pass out of our body through urination. For this treatment stem cells can be used to replace lost or malfunctioned insulin producing cell. Stem cells can also have used to protect active beta cells that produce insulin from attack of immune system.
It is neurodegenerative disorder. It effects brain and cause in decline of its functions such as memory, speech and though. Now a day approximately 70% of population effected by dementia is also effected with Alzheimer’s disorder. It is cause when the immune system cells microglia continue to consume arginine then those cell start to damage.
For its therapy lab experiments are continue on the lab mice in which stems cells are inoculated in brain cells of mice that can generate new connection with synapse as a result of this they will recover memory loss.
It is another neurodegenerative disorder. Parkinson diseases is also term as t motion disturbs because it effect motion and equilibrium function of the brain. It may also lead to sleep disability, stress, depression and unwary attitude. It is caused due to disturbance in Dopamine production.
For its treatment old therapy was used, where stem cells are transmitted through large and compact neurons blocks. But in this method transplant neurons are also become ill. So new therapy is generated after that include inoculation of solution consist of minute amount of neuronal stem cell through arteries. These stem cells are extracted from bone marrow as result of this new therapy illness is slow down due to production of growth factors that sustenance sick.
Parkinson disease and cloning
Other useful purposes in the therapeutics is as listed below
- Animal models can be produce through this based on human disease for the research study.
- SCNT methods can be used to detect that specific cancer may arise either due to genetic or epigenetic disorder.
- In genetic therapy.
Myths linked with cloning
There are some myths associate with cloning that are following
- Myth: Clones are unique animal’s DNA that are implanted onto other organism.
Fact: not at all, they are produce like any other animal born. only main difference is that they not need any sperm and egg fusion to develop an embryo. Instead of this clone embryo are produce by using complete cell or nucleus and then inoculating it to an egg cell that is enucleated. Then embryo is grafted to uterus of female and allow to grow as in in-vitro fertilization.
- Myth: offspring of a clone is just a clone and with passage of time each generation become weaker and face more problems.
Facts: absolutely not, they can give birth to offspring as like other animals through sexual reproduction. A breeder can use natural methods such as investor fertilization to breed clones. Thus offspring is clone but in fact resemble to offspring produce as result of sexual reproduction.
- Myth: SCNT is method that permit scientist to produce stem cells that are identical to patient thus not destroying embryo.
Fact: SCNT is scientific method for cloning, method if successful can produce embryo and scientist use them to isolate stem cells which can destroy embryo that only few days young.
- Myth: baby produce by cloning can be grown in artificial womb
Fact: no in real it is not possible scientist are working for fifty years to create an artificial womb but in vein. In1973, a life threating experiment was conducted on live born fetus resulted in ban on such kind of researches.
- Myth: Desire human cloning is conduct for evil purposes
Fact: no it just simple technique uses for benefit of mankind. To create somatic cells from SCNT for repair of damaged tissues and organs and for therapeutic purposes.
- Myth: they are always physically identical to each other in looks.
Facts: no this is not same for all. They may vary to each other in physical state such as skin margins and colors. But they may have identical genes because they consist of same set of genes but vary in their gene expression.
- Myth: life time of a clone is short span and is nearly same as of donor life span
Fact: their birth method is same as any other animal which is sexually reproduce but it poses shorter life span compared to them but not same to donor life period. Researches are conduct in this regard for better understanding aging process.
- Myth: people produce through cloning are used as replica for spare organs of human.
Fact: nothing could be done to a person that give him super power over normal human being. This practice is immoral and not done in any country.
- Myth: all humans clone with same genotype are rise in groups that share empathy and secret messages.
Fact: this is totally fiction nothing else. Such kind of assumptions are just manmade and have not solid ground reasons and also against morals of laws and federal.
- Myth: cloning is used to reproduce or to bring back ancestors.
Fact: it hardly recreates 1% of what our ancestor’s genes and only genotype not its phenotype. Because descendant has gene half from parents and half from environment thus cloning cannot develop what is from environment in our genes so it is just false assumption and not possible in reality.