A transgenic mouse strain expressing four drug-selectable marker genes

Area of Science:

• * Stem cell biology and genetic engineering.
• * Mammalian cell culture techniques.
• * Development of genetically modified mouse models.

Background:

• * Murine embryonic stem cells (ES cells) are typically cultured on feeder layers of murine embryonic fibroblasts (MEFs).
• * Gene targeting in ES cells often requires sequential selection for resistance to multiple drugs within a single cell line.
• * Current methods for generating drug-resistant MEFs can be resource-intensive.

Purpose of the Study:

• * To develop an economical method for producing multiple-drug resistant MEFs.
• * To establish a new mouse strain as a superior donor for MEF production.
• * To facilitate efficient gene targeting in ES cell research.

Main Methods:

• * Development of a novel mouse strain (DR-4).
• * Preparation of MEFs from the DR-4 mouse strain.
• * Assessment of MEF resistance to multiple drugs (G418, 6-thioguanine, puromycin, hygromycin).

Main Results:

• * MEFs derived from the DR-4 strain exhibited significant resistance to G418, 6-thioguanine, puromycin, and hygromycin.
• * Resistance levels were substantially higher than those typically employed for drug-resistant ES cell selection.
• * The DR-4 strain offers an economical source for producing these specialized MEFs.

Conclusions:

• * The DR-4 mouse strain is a valuable resource for generating multiple-drug resistant MEFs.
• * This advancement simplifies and improves the efficiency of gene targeting experiments in ES cells.
• * Economical production of resistant MEFs supports broader application of advanced genetic engineering techniques.