| First Author | Sweet HO | Year | 1991 |
| Journal | Mouse Genome | Volume | 89 |
| Pages | 258-9 | Mgi Jnum | J:14301 |
| Mgi Id | MGI:62472 | Citation | Sweet HO, et al. (1991) Greige (ge). Mouse Genome 89:258-9 |
| abstractText | Full text of Mouse Genome contribution: Research News: 2. Greige (ge). This is a new recessive coat color mutation that arose in the DBA/2J inbred strain in 1988 and has been located on Chromosome 1. Homozygotes on the DBA/2J background are easily identifiable at 6 days of age by coat color dilution, pale ears, feet and tail. Eye color is not affected. Homozygotes are not deaf. Adult homozygotes may develop coat color mosaicism and in two instances the entire coat color reverted to nearly full color. Homozygotes are viable, fertile, produce all ge/ge offspring, and on an agouti (C3HeB/FeJ) background are extremely difficult to identify. There may be a barely discernable lightening of agouti hair on the belly or a fleck of white on the dorsum. Homozygotes on the C57BL/6J background are slightly dilute and closely resemble sepia. Coat color may be considerably lighter than normal on the belly with variable flecking on the dorsum. Occasionally the nose appears grizzled. Matings between homozygotes on either of these two backgrounds may produce some phenotypically normal appearing progeny. An intercross in repulsion with sepia (sea) on Chr 1 produced no recombinant offspring in 119 progeny. No recombinants were found among the homozygous mutant F2 progeny tested from this cross (32 Chr). These results suggested that ge might be on Chr 1. The ge mutation is not an allele of sepia, however, because ge +/+ sea F1s have normal coat color. Isoenzyme differences between DBA/2J-ge and C57BL/6J inbred strains enabled us to confirm mapping to Chr 1. The linkage cross consisted of intercrossing F1 mice and typing Idh-1 and Pep-3 in the F2 mutant animals. A total of 21 mutant (ge/ge) F2 mice (equivalent to 42 chromosomes obtained in a standard backcross) were analyzed for the Idh-1 and Pep-3 alleles. The three point cross gave a recombination estimate of 30.95 +/-4.32% between ge and Idh-1 (13/42 chromosomes) and a recombination estimate of 16.67 +/- 6.71% between ge and Pep-3 (2/42 chromosomes) positioning ge very close to sepia. (H.O. Sweet and C.A. Spencer) |
