Assignment of the structural gene for argininosuccinate synthetase to proximal mouse chromosome 2

In order to develop linkage markers for the murine argininosuccinate synthetase locus (Ass-1), we have searched for restriction fragment length polymorphisms in the mouse genome using cloned sequences from the mouse arginosuccinate synthetase structural gene. Five restriction fragment length polymorphisms were found among the recombinant inbred progenitor strains AKR/J, BALB/cByJ, C3H/HeJ, C57BL/6J, C57L/J, DBA/2J, and SWR/J. Of these, four polymorphisms were found to distinguish the SWR/J strain from the other six strains, which all had the same fragment. The fifth polymorphism revealed differences among the progenitor strains for recombinant inbred strain sets AKXL, BXD, and SWXL. The strain distribution pattern for this polymorphism indicated close linkage of Ass-1 to Hc (the fifth component of complement) on proximal mouse chromosome 2 with a recombination fraction of 0.016 and a 95% confidence interval of 0.003 to 0.054. These data place Ass-1 in a syntenic group with the genes Hc, Abl, Fpgs, and Ak-1 whose linkage has been conserved between human chromosome 9q and mouse chromosome 2.     

A functional mouse ornithine decarboxylase gene (Odc) maps to chromosome 12: further evidence of homoeology between mouse chromosome 12 and the short arm of human chromosome 2

We have used a DNA probe specific for a functional mouse ornithine decarboxylase gene (Odc) in conjunction with a panel of Chinese hamster x mouse somatic cell hybrids to assign Odc to mouse chromosome 12. This assignment provides further evidence of genetic homoeology between a region of mouse chromosome 12 and the distal short arm of human chromosome 2.     

Heterogenous expression of ornithine decarboxylase gene in the proximal tubule of the mouse kidney following testosterone treatment

The expression of the ornithine decarboxylase (ODC) gene in the mouse kidney following testosterone treatment was examined using in situ hybridization histochemistry. Testosterone (n=5) or vehicle (n=5) was subcutaneously injected (1 mg/animal) into male BALB/c mice (8 weeks in age) 14 h before sacrifice. Animals were sacrificed under ether anesthesia, their kidneys were removed and immediately frozen in liquid nitrogen. Frozen sections (10-m-thick) were cut on a cryostat. Sections were hybridized with ³⁵S-labeled sense or antisense RNA probe. The hybridization continued for 24 h at 50° C and emulsion autoradiography was subsequently performed. A marked increase in ODC mRNA was exclusively detected in the proximal tubule of the renal cortex in the testosterone-treated animals. The hybridization signal was greater in the outer portion of the proximal tubule than in the inner portion. No significant hybridization signal was detected either in the distal tubule, renal corpuscle or peritubular tissues. These results indicate that testosterone induces the expression of the ODC gene in the proximal tubule of the renal cortex, leading to the increase in ODC activity in the same region.     

Assignment of the human homologue of Pim-1, a mouse gene implicated in leukemogenesis,to the pter-q12 region of chromosome 6

Summary Viral leukemogenesis in mice is frequently initiated by proviral activation of a highly conserved cellular gene called Pim-1. Here we report the chromosomal localization of the human homologue by Southern blot analyses of DNAs obtained from human-rodent somatic cell hybrids. The single copy human homologue was assigned to the 6pter-q12 segment.     

Assignment of d-amino-acid oxidase gene to a human and a mouse chromosome

Summary. A part of d-amino-acid oxidase gene was amplified in the human and mouse by polymerase chain reaction. The amplified fragments were ligated to plasmids and then cloned. The plasmids containing the parts of d-amino-acid oxidase gene were biotinylated and hybridized to human and mouse metaphase chromosomes. The chromosomal slides were treated with fluorescein isothiocyanate (FITC)-conjugated avidin. The hybridized signals were amplified with biotinylated anti-avidin antibody and FITC-avidin. The chromosomes were counter-stained with diamidino-phenylindole for assignment of the signal to a specific band. Using this fluorescence in situ hybridization (FISH), d-amino-acid oxidase gene was assigned to human chromosome 12q23–24.1 and mouse chromosome 5E3-F. Since these regions are syntenic between human and mouse, the present results indicate that the locus for this enzyme has been conserved through evolution. Received July 11, 2000 Accepted November 10, 2000     

Assignment of estradiol receptor gene to mouse chromosome 10

Differences in restriction fragment lengths were detected with murine estrogen receptor cDNA (clone MOR-100) between Chinese hamster and mouse. These were used to determine the chromosomal location of the estrogen receptor in the mouse by Southern blot analysis of DNAs obtained from a panel of mouse-Chinese hamster somatic cell hybrids. The mouse estrogen receptor gene was localized on mouse chromosome 10.     

Assignment of pancreatic ribonuclease gene to mouse chromosome 14

A pancreatic ribonuclease cDNA was used as a probe for Southern blot hybridization of genomic DNA from recombinant inbred strains of mice. The results indicated that the gene coding for pancreatic ribonuclease (Rib-1) can be assigned to mouse chromosome 14. Analysis of the congenic strain B10.D2(57N)Sn confirmed this assignment and indicated that Rib-1 is closely linked to the genes encoding the T-cell receptor alpha subunit (Tcra) and nucleoside phosphorylase-2 (Np-2).     

Intergeneric homology of the speC gene encoding biosynthetic ornithine decarboxylase in Escherichia coli.

A 32P-labeled fragment of DNA containing the speC gene, which encodes the biosynthetic enzyme ornithine decarboxylase of Escherichia coli, was used as a hybridization probe for homologous sequences in the genomes of gram-negative and gram-positive bacteria. The speC probe detected homologous sequences in the DNA of only four members of the Enterobacteriaceae (Citrobacter freundii, Salmonella typhimurium, Klebsiella pneumoniae, and Enterobacter aerogenes); no homology was detected with the DNA of other representative members of the Enterobacteriaceae and gram-negative and gram-positive bacteria.     

Purification of 12-O-tetradecanoylphorbol-13-acetate-induced ornithine decarboxylase from mouse epidermis

Ornithine decarboxylase was purified at least 1500-fold from mouse epidermis pretreated with five consecutive doses of 12-O-tetradecanoylphorbol-13-acetate and 3-isobutyl-1-methylxanthine at 3- to 4-day intervals. Following DEAE-cellulose chromatography and ammonium sulfate precipitation, ornithine decarboxylase was purified further by affinity chromatography. Ornithine decarboxylase was then radioactively labeled by covalently binding [3H]-alpha-difluromethylornithine to the enzyme following polyacrylamide gel electrophoresis under non-denaturing conditions. Following sodium dodecyl sulfate polyacrylamide gel electrophoresis and silver staining of protein, a band was identified that corresponded to a molecular weight of approx. 56,000, coincident with a peak of radioactivity. This is the first study to purify ornithine decarboxylase from mouse epidermis.     

Assignment of the gene for intercellular adhesion molecule-1 (Icam-1) to proximal mouse chromosome 9.

Intercellular adhesion molecule-1 (ICAM-1) is an integral membrane protein, a member of the immunoglobulin superfamily, and a ligand for LFA-1, a beta 2 leukocyte integrin. ICAM-1 has a tissue distribution similar to that of the major histocompatibility complex class II antigens and is likely to play a role in inflammatory responses. We have mapped this gene to proximal mouse chromosome 9 by using mouse-hamster somatic cell hybrids and an interspecies backcross. Since human ICAM-1 maps to chromosome 19, it joins the LDL receptor to establish a new conserved syntenic segment between human chromosome 19 and proximal mouse chromosome 9. Murine Icam-1 maps between Cbl-2 and the centromere in the same region as one of the susceptibility genes for insulin-dependent diabetes mellitus (Idd-2) that is postulated to play a role in immune function and inflammation leading to insulitis. The mapping of Icam-1 to the region known to contain the Idd-2 gene raises the question of whether the phenotypic differences attributed to the Idd-2 locus might be due to genetic variation in Icam-1.     

Assignment of uroporphyrinogen decarboxylase (UROD) to the pter----p21 region of human chromosome 1

The assignment of the human gene for uroporphyrinogen decarboxylase (UROD) to chromosome 1 is confirmed and further localized to the pter----p21 region through the use of human-mouse somatic cell hybrids. Human and mouse UROD were separated by electrophoresis and identified with antibodies to the human enzyme after electrophoretic transfer to nitrocellulose membranes.