Table I.
Kinds of Mice Used in Researcha
| Definition of breeding system | Perpetuation of breeding system | Reference |
|---|---|---|
| Random bred stock: Random mating within a large, heterogeneous population | Continue random mating, selection pairs with random numbers method | |
| Inbred strain: Brother-sister mating for more than 20 generations | Continue brother-sister mating | Green (1981a) |
| F1 hybrids: Mice from crosses between inbred strains | Cannot be perpetuated | Green (1981a) |
| Segregating inbred strain: Brother-sister matings system for more than 20 generations with heterozygosity for the mutations forced by (1) backcrossing, (2) intercrossing, (3)crossing and intercrossing, or (4) backcrossing and intercrossing | Continue brother-sister mating with heterozygosity forced by one of the four methods at left or with homozygosity forced by intercrossing homozygotes | Green (1981a) |
| Coisogenic inbred strains: Occurrence of a mutation within a strain | Perpetuate the mutation by (1) brother-sister mating within strain of origin, (2) backcross or cross-intercross system with strain of origin as parent strain, (3) brother-sister mating with heterozygosity forced by back- or intercrosses, or (4) brother-sister mating between homozygotes | |
| Congenic inbred strains: (A) Repeated backcross of mutation-bearing mice for 10 or more generations or (B) cross-intercross system for the equivalent of 20 or more cycles with an inbred parent strain | Perpetuate the transferred mutation by (2), (3), or (4) above. (1) may be used after 10–12 generations of backcrossing with periodic backcrosses to background strain | |
| Recombinant inbred strains: Brother-sister matings for >20 generations after crossing two inbred strains and their F1 to obtain and F2 | Continue brother-sister matings | Bailey (1971) |
| Recombinant congenic strains: Same as above except one or more backcrosses of F1 to one parent strain before beginning brother-sister matings | Continue brother-sister matings | Demant and Hart (1986) |
| Advanced intercross lines: Nonsibling matings from an F2 of a cross between two inbred strains | Continue nonsibling matings |
a
Modified from Green (1981 a).