How are transgenic (knockout) mice engineered?

Dr. Isabelle Seif engineered first transgenic mice which led to the accidental deletion of the MAO A gene. This created a mouse with no MAO A.


A mouse performing a beam test. The mouse is unable to keep its balance on a beam.


A normal mouse gene and a knockout mouse gene compared.


Selective enhancement of emotional, but not motor, learning in monoamine oxidase A-deficient mice, May 1997

Link to article: 1997 KimJJ-Selective


How do you “knock out” the MAO A or B Gene?

In this video Dr Shih explains how knockout mice or MAO-deficient mice are made in her lab. A colony of knockout mice were bred from these mice.

Normally, one uses homologous recombination, a method of replacing a portion of DNA with a modified gene construct to create a MAO-deficient mouse.