title: Assignment of the gene for cytoplasmic superoxide dismutase (Sod-1) to a region of chromosome 16 and of Hprt to a region of the X chromosome in the mouse.
abstract: In the search for homologous chromosome regions in man and mouse, the locus for cytoplasmic superoxide dismutase (SOD-1; superoxide:superoxide oxidoreductase, EC 1.15.1.1) is of particular interest. In man, the SOD-1 gene occupies the same subregion of chromosome 21 that causes Down syndrome when present in triplicate. Although not obviously implicated in the pathogenesis, SOD-1 is considered to be a biochemical marker for this aneuploid condition. Using a set of 29 mouse-Chinese hamster somatic cell hybrids, we assign Sod-1 to mouse chromosome 16. Isoelectric focusing permits distinction between mouse and Chinese hamster isozymes, and trypsin/Giemsa banding distinguishes mouse from Chinese hamster chromosomes. The mouse fibroblasts used were derived from a male mouse carrying Searle's T(X;16)16H reciprocal translocation in which chromosomes X and 16 have exchanged parts. Analysis of informative hybrids leads to regional assignment of Sod-1 to the distal half of mouse chromosome 16 (16B4 --> ter). Because the Chinese hamster cell line (380) used for cell hybridization is deficient in hypoxanthine phosphoribosyltransferase (HPRT; IMP: pyrophosphate phosphoribosyltransferase, EC 2.4.2.8), that part of the mouse X chromosome carrying the complementing Hprt gene can be identified by selection in hypoxanthine/aminopterin/thymidine medium and counterselection in 8-azaguanine. Mouse Hprt is on the X(T) translocation product containing the proximal region X cen --> XD.
mesh_terms: D000818:Animals; D002459:Cell Fusion; D002460:Cell Line; D002875:Chromosomes / Q000032:analysis; D006224:Cricetinae; D005260:Female; D007041:Hypoxanthine Phosphoribosyltransferase / Q000172:deficiency; D008297:Male; D051379:Mice; D009154:Mutation; D012730:Sex Chromosomes; D013482:Superoxide Dismutase / Q000235:genetics*; D014178:Translocation, Genetic; D014960:X Chromosome
chemical_list: D013482:Superoxide Dismutase; D007041:Hypoxanthine Phosphoribosyltransferase