Mapping of the mouse atrial natriuretic factor gene. Evidence for tight linkage to the Fv-1 locus.

The importance of atrial natriuretic factor (ANF) in the regulation of salt balance and blood pressure is now widely recognized, and it would be extremely informative for both physiologists and molecular biologists to have mutants available that exhibit abnormal expression of this peptide hormone. The most direct mutation would affect the structural gene itself by altering either its coding potential or its regulation. With this aim in mind, it is of considerable interest to accurately determine the chromosomal position of the ANF gene (Anf) in the mouse. This information would permit a comparison with known mutations and provide a means of screening for mutations at this locus. Using recombinant inbred mouse strains, we undertook the mapping of the mouse Anf gene and demonstrated linkage of the gene to the Friend virus susceptibility-1 (Fv-1) locus on chromosome 4. The mapping was performed using a restriction fragment length polymorphism extant between the two parental strains. No recombination event between Anf and the Fv-1 locus was evident in any of the 34 strains tested. The assignment of Anf to this region of chromosome 4 coincides with the reported position of the cribriform degeneration mutation, which includes in its phenotype an abnormal electrolyte distribution. We have, therefore, begun studying this mutation to determine whether a defect in ANF expression is the underlying cause of the phenotype. Thus far, we have found no major DNA rearrangement close to the Anf gene.