Mapping of aminoacylase-1 and β-galactosidase-A to homologous regions of human chromosome 3 and mouse chromosome 9 suggests location of additional genes

Conserved linkage groups have been found on the X and autosomal chromosomes in several mammalian species. The identification of conserved chromosomal regions has potential for predicting gene location in mammals, particularly in humans. The genes for human aminoacylase-1 (ACY1, N-acylamino acid aminohydrolase, E.C.3.5.1.14), an enzyme in amino acid metabolism, and β-galactosidase-A (GLB1, E.C.3.2.1.23), deficient in G(M1)-gangliosidosis, have been assigned to human chromosome 3. Using human-mouse somatic cell hybrids segregating translocations of human chromosome 3, expression of both ACY1 and GLB1 correlated with the presence of the p21→q21 region of chromosome 3. In a previous study, assignment of these genes to mouse chromosome 9 used mouse-Chinese hamster somatic cell hybrids, eliminating mouse chromosomes. To approximate the size of the conserved region in the mouse, experiments were performed with recombinant inbred mouse strains. An electrophoretic variant of ACY-1 in mouse strains was used to map the Acy-1 gene 10.7 map U from the β-galactosidase locus. These data suggest that there is a region of homology within the p21-q21 region of human chromosome 3 and a segment of mouse chromosome 9. Since the mouse transferrin gene (Trf) is closely linked to the aminoacylase and β-galactosidase loci, we predict that the human transferrin (TF) gene is on chromosome 3.