Random transgenesis is a classic strategy for preparing transgenic mice that overexpress genes, unaffected by emerging gene editing technologies. This method achieves overexpression of the target gene by randomly integrating foreign genes into the genome.

1. Technical Process:

Construction of overexpression vectors → Microinjection → Identification and selection of mice → Expression detection → Establishment of lines

Figure 1. Transgenic vector and mouse preparation process.

2. Technical Advantages:

(1) Can achieve broad-spectrum or tissue-specific overexpression of the target gene.

(2) Multi-copy insertion, resulting in higher expression levels than targeted insertion.

(3) Expression may be silenced or have an incorrect expression profile due to the influence of the integration site.

3. Successful Cases:

（1）BAC Transgenesis: Bacterial artificial chromosomes (BACs) are important tools for handling large fragments of DNA, known for their integrity and fidelity. A BAC containing hPCSK9 (RP11-55M23), which includes the complete human PCSK9 gene sequence, including a 64 kb-long 5’UTR, exons, and introns, as well as a 83 kb-long 3’UTR, was transformed into mice using random transgenesis. Positive mice have been obtained, and this model is an excellent model for studying the efficacy of antibody drugs, chemical drugs, and small nucleic acid drugs targeting hPCSK9. Data is being accumulated, and results will be updated in a timely manner.

（2）Random Transgenesis: The 1.28-fold genome of Hepatitis B was transferred into mice to obtain HBV-Tg mice. After screening, a mouse model with a high viral titer for evaluating hepatitis B drugs was obtained.

Figure 2. Efficacy evaluation of HBV-Tg mice.