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What Are Transgenic Mice?

What Are Transgenic Mice

What Are Transgenic Mice Used to Treat and Study?

What are transgenic mice and why have they become so popular in the past few years? So many scientific papers feature the use of transgenic mice. A common strategy is to create a humanized line to study a particular human gene or disease. Once a new strain of humanized mice is developed, it can be used to understand debilitating diseases such as cancer, Parkinson’s, Alzheimer’s, diabetes, and more. However, there is far more than meets the eye, as specific transgenic mouse models are achieved more accurately than ever before with the help of advanced technologies like CRISPR/Cas9. What are transgenic mice really used for? The specifics relating to answering this question could fill entire volumes.

An Introduction to Transgenic Mouse Models

So let’s start at the beginning: what are transgenic mice? The short answer is that they’re mice that have been artificially modified at a genetic level to include a foreign sequence, or transgene. This often involves the insertion of a human gene into the mouse’s genome to create a humanized mouse. The method for creating transgenic mice is versatile and it’s possible to create transgenic mice for many different kinds of research.

Knockin vs. Transgenic Mice

Different methods for making mouse lines can create confusion when trying to understand “what are transgenic mice made for.” Generally, transgenic mouse models are created through random insertion of a gene, while the knockin models feature the introduction of the gene at a specific locus within the mouse genome. Creating models with the knockin strategy is more complex but removes the unpredictable element that comes with random transgenic insertion. Carefully evaluating the options along with your research plans is crucial to the long-term success of your lab’s research.

The Usefulness of the Transgenic Mouse for Research

A new transgenic mouse model generated by random insertion of foreign DNA may provide a boost to your current research. Compared with most models transgenic mice can be created at a relatively low cost and in a shorter amount of time. If you’re studying a particular human gene for example you can investigate its function by making a transgenic model that expresses it in the mouse.

The Effective Generation of Specific Mouse Models

Over time as you continue to study the gene you may find that the random element that’s inherent in transgenic models becomes an obstacle. A common problem is that it’s better if the mouse gene is knocked out at the same time as the corresponding human gene is expressed. Since the transgene is inserted in a random location you’ll have to cross the new line with a knockout line and track two alleles throughout your research. A targeted knockin model can eliminate this by combining expression of the human sequence with knockout of the mouse sequence at a single genomic location. These advantages and others can make this model into a cornerstone of your research for years. However, if you’re focused on your immediate research objectives, a transgenic mouse may be the tool you need.