Recombinant retroviruses in transgenic mice

Production of Transgenic Mice by Pronuclear Microinjection

Pronuclear microinjection remains the most widely used method for the germline modification of mice and other species. The method is conceptually quite simple and at least in rodents can produce transgenic offspring with relatively high efficiency. Here, we describe the various components of the production of transgenic mice including a detailed list of materials and equipment. We outline in detail the preparation of animals, the retrieval, culture and transfer of embryos, the preparation of DNA, and the microinjection process. We have added a substantial collection of notes with helpful suggestions that reflect the many years of experience we have using this technology and our continuing efforts to improve animal welfare and the efficiency of producing transgenics.

Lentiviral transgenesis in mice via a simple method of viral concentration

Transgenic animals are important in vivo models for biological research. However, low transgenic rates are commonly reported in the literature. Lentiviral transgenesis is a promising method that has greater efficiency with regard to generating transgenic animals, although the transgenic rate of this approach is highly dependent on different transgenes and concentrated lentiviruses. In this study, we modified a method to concentrate lentiviruses using a table centrifuge, commonly available in most laboratories, and carried out analysis of the transgenic efficiency in mice. Based on 26 individual constructs and 627 live pups, we found that the overall transgenic rate was more than 30%, which is higher than obtained with pronuclear microinjection. In addition, we did not find any significant differences in transgenic efficiency when the size of inserts was less than 5000 bp. These results not only show that our modified method can successfully generate transgenic mice but also suggest that this approach could be generally applied to different constructs when the size of inserts is less than 5000 bp. It is anticipated that the results of this study can help encourage the wider laboratory use of lentiviral transgenesis in mice.

Infection of bovine cells of embryonic origin by amphotropic retroviral vectors

Two amphotropic-based mouse retroviral vectors carrying the neomycin-resistance gene were used to infect four bovine cell lines. Two cell lines, bovine kidney and spleen cells, were refractory to the infection while two independent bovine cells of apparent embryonic origin were infected by the amphotropic retroviral vectors at a measurable titer. Southern blot analysis reveals the presence of neomycin-resistance gene in the G418-resistant bovine cells. The results demonstrate the successful transfer of a gene to bovine cells of embryonic origin using a murine retroviral vector system.