Organ transplantation can save lives. Modern medicine can transplant almost all human organs and tissues, but rejection and lack of donors are still a headache. Because all the genetic material of human cloning comes from "primitive people", their organs are provided for the use of "primitive people". Genetic matching and histological matching are not afraid of rejection. But sacrificing one person to save another is neither economic nor moral. If only one organ such as heart, liver and kidney is cloned, all kinds of criticisms can be avoided.
It is still an amazing phenomenon that a cell with a "baton" of life can eventually develop into a complex life like human beings. When the sperm and the egg kiss for life, the fertilized egg gains great vitality and can continuously divide and differentiate cells, eventually forming a person with 200 trillion cells. Each of us took "half" the life code map from our parents and formed our own unique DNA spectrum table. There are 46 chromosomes in this blueprint, including 654.38+ million structural genes and 3 billion base pairs.
When the early embryo is 4 ~ 8 cells, the cells are totipotent. At this time, the cells are separated by embryo cutting technology, and the separated cells can re-form 4 or 8 cells. After that, embryonic cells gradually differentiate into the brain, heart, liver, kidney, limbs and reproductive system of human body, and the differentiated cells are no longer totipotent. The magic of Dolly the cloned sheep is that it "loads" the nucleus of somatic cells. Adult human cells are "directional" cells. For example, breast cells can only develop into mammary glands and cannot regain "totipotency". The greatest theoretical significance of Dolly's birth is that it proves that a fully differentiated somatic cell can return to the early primitive cell state under the "rebellion" of egg cytoplasm and preserve complete genetic information like an embryonic cell.
Cloning organs is a "directed development" technology. Developmental genetics is the most challenging and attractive research field in human genetics. It studies how the developmental program in human fertilized eggs is encoded on the genome, how genes are turned on, expressed and turned off in a certain time-space sequence, and how genes control the synthesis of various special protein, so that various fine cells can differentiate into organs and eventually develop into a complete person. This is an extremely complicated process, and the role of regulatory genes is far more important than structural genes.
People have found evidence of directional growth in plant tissue culture. The skin cultivated by cloning technology can be used in clinic. Recently, British scientists have bred a frog embryo without a head. Researchers say that this technology may be used in humans, cultivating headless clones and transplanting human organs and tissues.
Scientists believe that this technology may be suitable for cultivating human organs in embryo sacs, such as heart, kidney and liver, in an artificial uterus environment. People who need organ transplantation can use their own cells to obtain "directionally cultured" organs, thus eliminating the anti-rejection treatment for organ transplant patients. This technology will also greatly alleviate the shortage of transplanted organs.
To cultivate some embryos into needed organs, if there is no brain or central system, technically, the cultured tissues may not belong to embryos.
In any case, human beings do not have the strength and ability to solve the problem of gene regulation at present. Scientists predict that at the beginning of 2 1 century, human developmental genetics will become the main research hotspot in the field of biology.
In vitro culture of cloned organs is also an arduous task, which is different from traditional cell culture and cannot be put into human uterus for development. Humans have mastered the embryo form of artificial uterus-in vitro fertilization technology, and in vitro fertilized embryos can grow in test tubes for several days. Now, the goal of scientists is a real "artificial uterus".
2 1 century is the century of biotechnology, and modern genetics has left a very broad thinking sky for people, allowing promising scientists to gallop and cultivate. Biotechnology has great magic, and cloning organs is only part of it.