Application of Transgenic Animals

The basic substance of heredity is DNA, and the gene is a DNA fragment with genetic effects on the chromosome. It can be called the genome for all genetic information stored in the complete set of chromosomes. Since the genetic composition of different species and different individuals is different, for the individual animal, the non-self genetic component belongs to the foreign gene. If the foreign gene is integrated or introduced into the animal chromosome gene, the foreign gene is Known as the transgene, this animal is a transgenic animal, such as transgenic mice service.

Transgenic animal expression systems, including exogenous genes, expression vectors and recipient cells, genomic transfer is nuclear transfer and animal cloning technology, synthetic and design genes, whole genes and even genome transgenic technology is synthetic biology.

Transfer method

The mammalian gene transfer method is to inject the reconstructed target gene (or genomic fragment) into the fertilized egg of the experimental animal by microinjection, etc., and then implant the fertilized egg into the fallopian tube of the recipient animal to develop it. A transgenic animal carrying a foreign gene.

Depending on the method and subject of foreign gene introduction, the current methods for producing transgenic animals include microinjection, retrovirus, embryonic stem cell, electric pulse, and sperm carrier.

Applications

Basic theory

Developmental Biology

Transgenic animals can be used to observe the specific expression, shutdown and regulation mechanisms of the target gene at different developmental stages of the embryo, and to understand the role of regulatory sequences (such as enhancers, promoters) in tissue-specific expression, such as human renin gene in mice. Specific expression in vivo may be related to the 5' flanking sequence of the gene. In addition, transgenic animals can be used to identify genes (including endogenous genes) and their activities during animal development, as well as to express the expression characteristics of unknown genes associated with animal development.

Genetics

Using naturally-mutated or artificially modified genes as exogenous genes, constructing transgenic animals, studying the phenotypic effects of the abnormal genes, can understand the relationship between gene structure and function, and can also be used for genomic imprinting analysis and correction of genetic defects.

Medical Research

Cardiovascular diseases

Various factors regulating cardiovascular function, such as translipoprotein and plasminogen, can be used to understand their physiological functions and functions through transgenic animals, and establish transgenics such as atherosclerosis, sudden hypertension, and venous occlusion. Animal model.

Oncology

The discovery of tumor genes is a major breakthrough in oncology research in the past 10 years, and more than 100 tumor genes such as breast cancer genes have been discovered. Experiments have shown that various vertebrates carry tumor genes, which usually do not cause cell carcinogenesis. Only under certain conditions can they be activated to cause cancer cells to proliferate and cause cancer. The establishment of transgenic animals with tumor genes can understand which tissues are sensitive to tumor targeting gene transformation activity, the relationship between tumor formation and their genes, and the influence of tumor gene growth and differentiation.

Genetic disease

Usually, a normal foreign gene is introduced into a target cell of an animal body to compensate for the defective gene, change the genetic material of the diseased cell, and perform gene therapy. Conversely, by introducing a dominant disease gene or one or even more foreign genes into an animal artificially, a transgenic animal model of hereditary diseases can be prepared to study and treat human genetic diseases. For example, Hungtington introduced the chorea gene into mice and established a chorea animal model. Redhead introduced the normal mouse MBP (myelin basic protein) gene into tremor mice, and the tremor of the mouse. The symptoms disappear.

Immunology

Babinet found that although transgenic mice produced HBsAg, there was no pathological change within 6 months, showing a persistent viral state. These results indicate that hepatocyte damage in patients with hepatitis B is not directly caused by HBVAg expression of HBV, but is caused by an immune response to viral antigens on the membrane of liver cells. Therefore, a transgenic mouse model can be used to study the relationship between immune tolerance and hepatocyte injury to explore the pathogenesis. In addition, transgenic mice production have provided new tools for studying the functions of primary and secondary major histocompatibility antigens.