A review of biological cloning technology, a brief description of the principles of cloning technolo

Let's take the very famous cloned sheep "Dolly" as an example to analyze it: First, the experiment involved three sheep A, B, and CIf you want to clone a sheep, then take a cell of a sheep and take out its nucleus (which contains most of the genetic material), and the cytoplasm is not needed; Then take the egg cells of sheep B (female), remove the nucleus, and leave the cytoplasm, which is called the enucleated egg cell, and the enucleated egg cell is rich in nutrients.

The nucleus of A is implanted into the enucleated egg cell of B to form a new cell. The early embryo formed by this cell is implanted into the uterus of the C sheep (female). The result is a new individual.

This new individual is almost identical to A because it is implanted with the nucleus of A, which contains most of the genetic material. This is an example of cloning technology, which is still in essence asexual reproduction. Why is it so troublesome?

Because the overall totipotency of animal cells is inhibited, it is not possible to directly take a complete cell of sheep A to clone cryptojube, but the nucleus of animal cells has totipotency, which can be expressed by implanting an enucleated egg cell. So clones in general do just that.

Clone is a transliteration of the English word "clone". When used as a noun, it denotes a group of genetically identical DNA molecules, cells, or individuals that have been bred from a common ancestor. When used as a verb, it refers to this process of asexual reproduction.

In recombinant DNA technology, gene cloning is the operation of inserting specific genes or genomes into DNA vectors that can replicate autonomously and introducing them into parasitic cells for proliferation, thus providing an effective way for the mass reproduction and growth of genetically identical biological strains. The advent of cloning technology is bound to have a far-reaching impact on the development of human society.

There are also various risks associated with cloning animals and plants, as a hereditarily identical sheep or tomato can be swept away by some sudden disease. Humans can think of genetic engineering as a fallback for declining fertility or for producing computers that are getting smarter and smarter, but we should be proud of our diversity above all else.

This is a kind of cell reproduction, and the principle of this can only be explained by university teachers.

Categories: Education, Science, >> Science & Technology.

Analysis: As far as I know, the simplest "clones" are clonal antibodies ,—— monoclonal antibodies.

For a long time, in order to obtain antibodies, we used the method of repeatedly injecting a certain antigen into the animal, and then sorting the required antibodies from the weight of zoology. Antibody obtained in this method is not only low yield, but also poor specificity, purity and research exploration of antibodies. They found that B lymphocytes in the body can produce more than a million specific antibodies during the animal occurrence year, but each B lymphocyte secretes one specific antibody.

Therefore, in order to obtain a large number of single antibodies, it is necessary to reproduce asexually with a single effector B lymphocyte, that is, to form a cell population through cloning, and such a cell population may produce a monoclonal antibody with a single chemical nature and strong specificity.

Preparation of monoclonal antibodies:

The Argentine scientist Cesar Milstein (1926-) and the German scientist Kohler continued to explore and try on the basis of the work of their predecessors, and gave full play to their imagination to design an experimental scheme rich in field shape. They came up with the idea that Hugo fused a type of cell that could proliferate in vitro with an effector B lymphocyte, and the resulting fused cells could proliferate in large quantities to produce a sufficient number of specific antibodies.

According to this hypothesis, they first injected antibodies into mice and then obtained antibody-producing effector B lymphocytes from the mouse spleen, fused with mouse myeloma cells under the induction of extinguishing Sendai virus or polyethylene glycol, and screened for hybridoma cells in a specific selective medium. Because hybridoma cells inherit the genetic material of both parent cells, they not only have the ability of B lymphocytes to secrete specific antibodies, but also have the ability to proliferate in large quantities under the condition of myeloma cell carrier culture. They cultured hybridoma cells, selected populations of cells capable of producing the desired antibodies, continued culture, and obtained a sufficient number of cells to be cultured in vitro or injected into the intraperitoneal cavity of mice for multiplication.

In this way, a large amount of monoclonal antibody can be extracted from the cell culture medium or the ascites fluid of mice.