Mutations whenever possible are maintained on an inbred background, usually the one on which the mutation arose. Others may require transferring to, and maintaining on, a hybrid background, to provide sufficient numbers of affected offspring to investigators, to increase the longevity of affected mice and to conserve space. Here we describe some of the common breeding schemes for maintaining recessive mutations and what genotypes are available from each. This is commonly referred to as the cross-intercross system of mating. Ovary Transplantation Recessive mutations that are more difficult to maintain may require special manipulation for continued maintenance.
Ovarian transplantation is one technique frequently used.
The ovary transplantation method can easily be done with mutants on standard inbred strains as long as the ovary is fertile and a compatible host subline or a hybrid with an appropriate color marker is available. The agouti locus serves as a coat color marker to distinguish progeny from the host and donor ovaries. Reproductive performance for females bearing transplanted ovaries is similar. Breeders are usually retired at 10 months of age. The Jackson Laboratory.