Cloning process

Cloning is the production of genetically identical living structures to its basic structure. Genetic variations are absent. Cloning occurs naturally in asexual reproduction and vegetative microbes multiplying plants. asexually reproduced as Amoeba proteus lower animals also produce clones.

monozygotic twins are identical clones also as formed by division of two or more cells early embryo into two equal parts. Both have the same genetic characteristics. Clone is, therefore, an exact carbon copy or copies of a single live parent. artificial cloning has been achieved in the higher animals. Dolly is a clone of her mother. Cloning is the cloning of various cell types, gene cloning, microbial cloning, the cloning of plants and animal cloning.

Cell Cloning

Cell cloning is the formation of multiple copies of the same cell. Clone cells are genetically identical, morphologically and physiologically. cell cloning is necessary when:

• The multiplication of cells having recombinant DNA (recombinant DNA) and obtain the required product as enzyme, hormone, antibody, etc., in good quantity, for example, insulin, monoclonal antibodies.
• The biochemical analysis to be performed,
•  Study of effect of different factors on the structure and functioning of identical cells,
• Study the process of differentiation,
• The maintenance of inbred lines in unicellular organisms,
• The maintenance of rDNA and cDNA libraries of genes

Totipotency is the ability of a cell to grow into a complete organism. It is present in most plant cells. Conversely, pluripotency is the ability of a cell to develop ИПу Ot cell type in the animal body, for example, kidney cells or heart cells or nerve cells. Generally, all plants but animals are totipotent single fertilized egg (zygote) and cells in the blastocyst embryonic stem are totipotent. However, techniques have been developed for culturing animal cells.

A small sized animal tissue is taken in liquid nutrient. Protease and calcium-binding agents are added to it. The culture is stirred mechanically. Separate cells. The plant tissue can be taken similarly in a liquid nutrient medium and mechanically agitated when cells are separated. The separated cells also tend to split. With the help of a micropipette, individual fresh culture media for multiplication and the formation of clones of cells are added.

Gene Cloning

the cloning of genes is the formation of multiple copies of the same gene. DNA is extracted from an organism breaking the cells, the separation of the cores and the breakage of the nuclear envelope. The separated DNA is subjected to endonuclease. DNA fragments were passed through electrophoresis.

The selected gene is separated. It can be multiplied directly by polymerase chain reaction (PCR) using Taq polymerase. Alternatively gene can be made to match the DNA plasmid and another passenger to form recombinant DNA. The latter is inserted into a host into which the gene can be multiplied with the multiplication of host.

Applications of Gene Cloning

Medical Utility

Bacteria can be used as living plants synthesize insulin, growth hormone, interferon, vitamins and antibodies by introducing genes encoding these substances them with plasmids.

Agricultural Utility

Nitrogen fixation bacterial genes can be transferred to the main crops to increase food production without using expensive fertilizers.

Defective Genes in the Foetuses

Recombinant DNA technology is useful to know - defective genes in fetuses. Some of these genes can also be repaired.

Gene Library

The various clones representing all genes of an organism are called gene library of this organism. Gene library, a clone having a specific gene can be identified and this gene can be multiplied by the relevant clone growth in culture for study. The base sequence of this gene can be found.

From the base sequence, the amino acid sequence of a polypeptide can work on the basis of triplet code.

Microbial Cloning

Microbes multiply asexually. They produce clones. Cloning way millions of copies of the same microbe. Therefore, once a desired strain created, the microbe is multiplied and used commercially. Traditionally they have been used commercially for obtaining a number of important products such as yogurt, cheese, vinegar, lactic acid, vitamins, antibiotics and alcoholic beverages. They are constantly being improved through mutations for better performance. A number of genes have been introduced into microbes to obtain therapeutic importance bio-chemical, bio-chemical industrial products and other functions.

Plant Cloning

It takes place through vegetative propagation and tissue culture. cloning plant is useful for rapid multiplication of GM, agronomically important and rare plants. The important plants are first genetically changed through mutations, hybridization or genetic manipulation to incorporate features such as disease resistance, drought resistance, herbicide tolerance, high yield, early maturity, foodstuffs (eg , GMFS as vitamin a rich Rice, lysine rich pulse), etc. Cloning is then performed quickly through tissue culture.

meristematic zones present in the roots and shoots vertices are preferred for rapid growth. They are disinfected, washed, sectioned and placed on culture medium. Cells are separated. Each cell forms a callus which can be sub-cultured. The callus is treated with hormones to induce organogenesis and form seedlings and plants.

Animal Cloning

The formation of one or more genetically identical animals in a single animal father is called cloning animals. Hydra sprouting produce clones. Monozygotic twins (identical twins) are also clone each other. They develop from a zygote division of early embryo. Dasypus dasypus (armadillo) always produces a clone 4-8 identical offspring thereof formed from a single zygote sex.

Gurdon’s Experiment

The first successful experiments in cloning animals conducted by Gurdon (1962). He took the intestinal epithelial cells or tadpole. the core of the epithelial cell is separated. The core is inserted into the free core unfertilized egg Xenopus laevis (frog). The egg had a normal development and produces a toad. It was a clone of that toad who donated his heart.

The World’s First Cloned Mammal (Fig. 6.46 & 6.47)

Wilmut and colleagues (1997), at the Roslin Institute in Edinburgh (Scotland), produced the first cloned mammal in the world a sheep named Dolly. It was an important development in animal cloning. They took cells from the udder of a six year old sheep. unfertilized egg from another adult sheep was taken.

The egg was enucleated. Not nucleus of a cell from the udder fall was removed and inserted into the enucleated egg. In nutrient medium egg began to experience a split. The early embryo is implanted in the uterus (womb) of a third sheep. The surrogate mother gave birth to normal healthy lamb, Dolly, on 13 February 1997. Subsequently, several cloning experiments have been performed successfully.

Clone of Asian Gaur

Scientists from Massachusetts (USA) have recently cloned an endangered species, the Asian gaur (Gaur) - A horned mammal hump. It was cloned from a single skin cell taken from an Asian gaur died. The skin cell was fused with the egg of a cow, whose gene was deleted. The fused cell was transferred to the uterus (womb) to another cow. The gaur calf was born. Asian gaur is the first endangered species to be cloned and cloned the first to take shape in the womb of another species animal.

Cloning of Cattle

Japanese scientists have cloned livestock in a different way. They have succeeded in growing up to eight identical calves a fertilized cell his mother (Fig. 6.48). When the mother cow has mated with the bull, which has fertilized egg (zygote) in her womb. This cell is divided into two and then four, then eight.

This embryo is removed from the matrix. Embryonic cells are then separated using an enzyme. Every single cell is maintained in a nutrient medium, and later implanted in the uterus of a different cow "foster mother." The mother's womb must accept host cell and make it grow. Each cell grows in a healthy environment normal calf, baby.

Human Cloning

Although human cloning can help preserve an individual's desired genotype can remain a presumption in the near future due to some unresolved practical difficulties or technical and ethical reasons. Regarding the fears expressed regarding the production of human clones in the near future is concerned, it is a fact that most of the features of human behavior are acquired or learned.

Whatever we do or think is mostly a derivative activity or activity modified through learning or training. As such, human clones, if they occur in the future, it may not be behaving identically with his "clone parent". For example, no differences in behavior or the way of working of identical twins reared under different conditions of life occur. Besides this, it is known that gene expression is influenced by many factors and the environment is one of them.

Many of hereditary diseases in humans are caused by recessive genes in homozygous state. heterozygous individuals are carriers of harmful genes. The frequency of heterozygous carrier is said to be greater than the number of homozygous individuals.

Human cloning may lead to dangers of inbreeding and frequency of homozygous individuals suffering from disorders can increase marriages heterozygous clones. Therefore cloning can adversely affect genetic diversity and therefore reduce resistance to diseases of the body as seen in monoculture.

Human cloning does not rule out the involvement of male sexual partner in reproduction. However, sexual reproduction involves the fertilization of the egg by the sperm is essential for survival. genetic variation in offspring that are more adaptable and adjust for natural selection occurs. The cloning of plants and animals, therefore, may be more beneficial to mankind than human cloning.

Application of Animal Cloning

Pig is considered a suitable donor organs for transplant to humans. genetically modified pigs or swine breeds suitable can be cloned for organ transplantation. The population of endangered species of animals can be increased by cloning. Cloning can be very used to improve pedigree animals. superior races of animals can be multiplied by this technique.