What are transgenic mice?
The exogenous recombinant genes are transfected into the genome of the animal receptor, and the genes can be expressed in vivo of the animals. Transgenic animal expression system includes exogenous gene, expression vector and receptor cell. the transfer of genome are nuclear transplantation and animal cloning technology. Artificial synthesis, design of genes and genome of the transgenic technology belong to synthetic biology.
In 1974, Rudolf Jaenisch created the first mouse to carry exogenous genes by injecting DNA of SV40 virus into the blastocyst of mice. Later, researchers injected the Murine leukemia virus into the mouse embryos, which were stably inherited in the mice, and the exogenous genes could be stably expressed in the offspring. These mice that are genetic stably and can express exogenous genes are that we call transgenic mice now in general.
What are transgenic animals model?
For ordinary transgenic genes, the expression region will depend on the promoter. If we choose the promoter expressing the whole body, like Rosa26, CAG, etc, the whole body-expressed transgenic mice can be produced. If the promoter of a number of tissue-specific genes is chosen, we will gain transgenic mice expressing the specific tissue. For example, under the role of AP2 promoter, the transgenic mice with specific expression of adipose tissue will be gained.
It should be noted that this strategy is to inject the gene fragment directly into the zygote of mice. The transgenic fragment will be randomly inserted into the mouse genome. Because it is completely random, it may be inserted into some of the inhibition zone leading to the gene transfer, but also it may be inserted into some of the enhanced zone leading to the gene high-expression. The first generation of transgenic mice are called founder. Because of the randomness, each founder is not the same. Each founder’s original species is called line. The expression of different lines may be different.