METHOD FOR PRODUCING MODEL ANIMAL, AND MODEL ANIMAL
Provided are: a method for producing a model animal which has a desired lifetime, and in which a predetermined biological reaction can be induced
and a model animal. According to the present invention, a first individual in which a gene of interest is heterozygously deficient is produced using a first ES cell originated from a non-human mammal. On the other hand, a fragment containing a homologous gene that has homology with the gene of interest is produced. Using a second ES cell that is so adapted that a predetermined region on X-chromosome of the mammal can be substituted, the fragment is introduced into the second ES cell, thereby producing a substituted ES cell in which the predetermined region is substituted by the fragment. Using the substituted ES cell, a second individual is produced. The first individual and the second individual are mated with each other, thereby producing a model animal.