The long-range restriction map surrounding the mouse agouti locus reveals a disparity between physical and genetic distances.
Isolation of a gene based on its location, which depends on aligning physical landmarks with the genetic map, can yield basic information about genome structure and organization. As a first step toward isolating the mouse agouti (A) locus, we have begun to define the physical position of this gene relative to genetically linked DNA probes from the Psp, Emv-15, and Src loci. Using a combination of pulsed-field gel techniques that include partial digestion with rare-cutting restriction enzymes and analysis of polymorphic sites present in certain inbred strains, we have constructed long-range restriction maps for each of the probes that span a total of more than 3000 kb. The Src and Emv-15 probes are less than 600 kb apart, but are separated from the Psp probe by at least 1500 kb. By determining the position of a 75-kb deletion that inactivates agouti function, we have localized the A locus to within 500 kb of the Psp probe, but more than 600 kb away from the Emv-15 probe. These physical distances contrast with the known recombination frequencies, 3 +/- 3 cM for A-Psp and less than 0.3 cM for A-Emv-15, and suggest that recombination between A and Emv-15 may be suppressed.
Barsh
G S
GS
Department of Pediatrics, University of California, San Francisco 94143.
Epstein
C J
CJ
D000818:Animals; D002478:Cells, Cultured; D002874:Chromosome Mapping; D003001:Cloning, Molecular; D003360:Cosmids; D015342:DNA Probes; D004279:DNA, Viral / Q000032:analysis / Q000235:genetics; D004587:Electrophoresis, Agar Gel; D005796:Genes; D008040:Genetic Linkage; D006200:Hair Color; D006801:Humans; D051379:Mice; D008807:Mice, Inbred BALB C; D010860:Pigments, Biological / Q000235:genetics*; D012150:Polymorphism, Restriction Fragment Length; D011995:Recombination, Genetic; D015183:Restriction Mapping; D012471:Salivary Proteins and Peptides / Q000235:genetics
C045623:BPIFA2 protein, human; C511597:Bpifa2 protein, mouse; D015342:DNA Probes; D004279:DNA, Viral; D010860:Pigments, Biological; D012471:Salivary Proteins and Peptides