Assignment of the human gene for β-glycerol phosphatase to chromosome 8

The segregation of the human gene for β-glycerol phosphatase (GPB) was examined in human-Syrian hamster and human-Chinese hamster somatic cell hybrids. Electrophoretic analysis of the GPB in hybrids suggested that the enzyme is a dimer. Human GPB cosegregated with chromosome 8 in the twenty-five hybrids examined.     

Mapping of human fibronectin receptorβ subunit gene to chromosome 10

Human-mouse hybrid cells were examined by indirect immunofluorescence with Mab DH12, a monoclonal antibody that recognizes the subunit of the human fibronectin receptor. Cells that expressed the antigen at their surface were sorted by FACS and karyotyped. Immunoaffinity chromatography on Mab DH12 was used to confirm the presence of the human antigen. The chromosome assignment was strengthened by isozyme analysis of markers for chromosomes 9 and 10. The results are suggestive for a 10p mapping of this subunit of the fibronectin receptor. Since the gene coding for the subunit of the VLA proteins was previously assigned to the same chromosome, our result could provide further evidence for the relationship between the subunit of the human fibronectin receptor and the VLA protein family.     

Assignment of human thyrotropin-releasing hormone (TRH) receptor gene to chromosome 8

The human gene encoding thyrotropin-releasing hormone receptor was assigned to chromosome 8, using human-Chinese hamster ovary somatic cell hybrids, analyzed by Southern hybridizations. Hybridization was carried out with a³²P-labeled fragment of the human TRH-R genomic DNA. Hybridization of this probe to a human specific 10.5-kb DNA fragment of EcoRI-digested WBC DNA was used to localize the human TRH-R gene. No hybridization, by contrast, was seen with this probe and hamster DNA after EcoRI treatment. Results from 18 somatic cell hybrids corroborated unequivocally that the human TRH-R gene can be assigned to human chromosome 8.     

Assignment of the human acid α-glucosidase gene (αGLU) to chromosome 17 using somatic cell hybrids

Hybrid clones (MOGs) were made between the mouse line RAG and a primary fibroblast line from an individual of the rare alphaGLU 2 phenotype. Fifteen independent primary clones and 32 subclones were tested for the presence of human alphaGLU after separation of the human and rodent enzymes by starch gel electrophoresis. Twenty-three other human-mouse hybrids from six different crosses were analysed for the presence of human alphaGLU by exploiting a difference in the thermostability of the human and mouse enzymes. The hybrids were also analysed for up to 25 other enzymes which were used as markers for different human chromosomes. Two of the MOG hybrids were karyotyped and karyotype data were already available for a number of the other hybrids. The combined results demonstrate that alphaGLU is located on chromosome 17, and probably on 17q.     

Assignment of human gene encoding testis-specific lactate dehydrogenase C to chromosome 11, region p14.3-p15.5

The human gene coding for lactate dehydrogenase C (LDHC), a testis-specific isozyme, has been assigned to a refined region of chromosome 11, p14.3–p15.5, in which the lactate dehydrogenase A gene LDHA also resides, by using somatic cell hybrids and in situ chromosome hybridization. This assignment clearly indicates the close physical proximity of the LDHC and LDHA genes and supports the evolutionary closeness of these two isozymes.     

Assignment of human preprothyrotropin-releasing hormone (TRH) gene to chromosome 3

The human gene encoding preproTRH (thyrotropin-releasing hormone) was assigned to chromosome 3, using human-Chinese hamster ovary somatic cell hybrids, analyzed by Southern hybridizations. Hybridization was carried out with a³²P-labeled human preproTRH cDNA labeled by the method of random priming (3). Hybridization of the cDNA probe to a human specific 4.8-kb DNA fragment of EcoRI-digested WBC DNA was used to localize the human preproTRH gene. No hybridization, by contrast, was seen with human preproTRH cDNA probe and hamster DNA after EcoRI treatment. Results from 29 somatic cell hybrids corroborated unequivocally that the human preproTRH gene can be assigned to human chromosome 3.Supported in part by USEHS grant DK37378.     

Assignment of the vascular smooth muscle actin gene ACTSA to human chromosome 10

Human vascular smooth muscle actin gene (ACTSA) was cloned and its unique sequence was used as the hybridization probe for Southern blot analysis of DNAs from 18 rodent-human somatic cell hybrids; the gene was assigned to human chromosome 10. Regional mapping by in situ hybridization showed that the gene is located on the long arm (q22-q24) of the chromosome. Thus, the gene is on a different chromosome from the other four actin genes so far examined.     

Assignment of the gene encoding cytosolic phosphoenolpyruvate carboxykinase (GTP) toMus musculus chromosome 2

The structural gene Pck-1, encoding cytosolic phosphoenolpyruvate carboxykinase (GTP) (PEPCK; EC 4.1.1.32), has been assigned to mouse chromosome 2. This assignment was made based on genomic Southern transfer of rat-mouse and hamster-mouse hybrid DNAs using a rat kidney cloned cDNA of the PEPCK gene as a probe. Conclusive evidence for the cosegregation of the PEPCK gene with mouse chromosome 2 was obtained using a monochromosomal microcell hybrid that selectively retained a Robertsonian translocation between mouse autosomes 2 and 8 and its back-selected hybrid clone.     

Assignment of the polymorphic intestinal mucin gene (MUC2) to chromosome 11p15

A cDNA coding for a mucin expressed in intestine has recently been cloned (Gum et al. 1989). We describe here the use of this cDNA to map the gene (MUC2) to human chromosome 11 using somatic cell hybrids, and to make the regional localization to 11p15 by in situ hybridization. Analysis of the CEPH (Centre 'Étude du Polymorphisme Humain) families revealed that MUC2 forms part of the tight linkage group on llpl5 which contains HRAS, INS, TH and HBBC.     

Assignment of the human ARNO3 gene (PSCD3) to chromosome 7p21 by radiation hybrid mapping

The chromosomal localization of the human ARNO3 gene ( PSCD3 ) was determined using monochromosomal somatic cell hybrid and radiation hybrid mapping panel. PCR analysis of a hybrid DNA panel localized the ARNO3 gene to human chromosome 7. The analysis of the Genebridge4 radiation hybrid panel using PCR amplification located the ARNO3 gene between NIB1822 (9.5 cR) and D7S481 (5.5 cR) with a lod score of >3.0. This region is located in the human chromosome band 7p21.     

Assignment of an oligomycin-resistance locus to human chromosome 10

An oligomycin-resistant variant of human fibrosarcoma HT1080 was isolated and characterized as nuclear and codominant. The mutant was stable, was not cross-resistant to respiratory inhibitors, and it contained a mitochondrial ATPase which was less sensitive to oligomycin. Hybrids formed between the human mutant and a mouse cell line expressed the resistance phenotype. By a detailed karyotypic analysis of these hybrids using trypsin-Giemsa banding it was found that resistance to oligomycin correlated with the retention of two human chromosomes 10. The hybrid lines contained only mouse mitochondrial DNA as shown by analyses of mitochondrially synthesized proteins and mitochondrial DNA. The study assigns an ATPase oligomycin-resistance locus to human chromosome 10 and suggests that mouse and human subunits can combine in a functional enzyme complex.     

Assignment of the ǵene for F-type phosphofructokinase to human chromosome 10 by somatic cell hybridization and specific immunoprecipitation

A method of specific immunoprecipitation of minor isozymes was developed and applied to the detection of human F-type phosphofructokinase in man-rodent somatic cell hybrids.
This method allowed us to assign the gene for this newly discovered isozyme of phosphofructokinase to chromosome 10.     

Assignment of the gene for cytosolic alanine aminotransferase (AAT1) to human chromosome 8

The segregation of human cytosolic alanine aminotransferase (AAT1) and the individual human chromosomes has been studied in 27 secondary and tertiary rat hepatoma-human (liver) fibroblast hybrids. The staining solution used to visualize AAT activity on starch gels was specific for AAT since it was visualized only when all components of the stain were present. The locus for human AAT1 has been assigned to chromosome 8.     

A polymorphism of MS4A2 (−109T>C) encoding the β-chain of the high-affinity immunoglobulin E receptor (FcɛR1β) is associated with a susceptibility to aspirin-intolerant asthma

BACKGROUND AND OBJECTIVE: The MS4A2 gene, the beta chain of the high-affinity receptor for immunoglobulin (Ig)E, has previously been linked to atopy and asthma. The beta-chain of FcepsilonR1 enhances receptor maturation and signal transduction capacity, leading to the release of proinflammatory mediators and cytokines that can exacerbate the symptom of asthma. This study was performed to evaluate whether two genetic polymorphisms of the FcepsilonR1beta gene (FcepsilonR1beta-109T > C and FcepsilonR1beta E237G) are associated with aspirin-intolerant asthma (AIA). The MS4A2 gene polymorphisms (FcepsilonR1beta-109T > C and FcepsilonR1beta E237G) were determined by SNP-IT assays in patients with AIA (N = 164), aspirin-tolerant asthma (ATA, N = 144) and normal controls (NC, N = 264) recruited from a Korean population. RESULTS: The genotype frequencies of FcepsilonR1beta-109T > C and E237G polymorphisms were not significantly associated with the pathogenesis of AIA. However, FcepsilonR1beta-109T > C polymorphism was significantly associated with the presence of specific IgE to Staphylococcal enterotoxin B (SEB); the number of subjects carrying both homozygous TT genotype of FcepsilonR1beta-109T > C and specific IgE to SEB was significantly higher in the AIA group when compared with the other control groups (P = 0.01, odds ratio (OR) = 7.723, 95% confidence interval (CI) = 1.327-39.860 for AIA vs. ATA; P = 0.02, OR = 6.364, 95% CI = 1.149 approximately 35.229 for AIA vs. NC). In addition, luciferase reporter assays also showed that the FcepsilonR1beta-109T allele was associated with higher promoter activity of MS4A2 in both RBL-2H3 and A549 cell lines. CONCLUSION: FcepsilonR1beta-109T > C polymorphism may increase expression of MS4A2 by mast cells, leading to enhanced release of proinflammatory mediators in the asthmatic airway, contributing to increased susceptibility to AIA.     

Assignment of the lactotransferrin gene to human chromosome 3 and to mouse chromosome 9

Lactotransferrin (LTF), a member of the transferrin family of genes, is the major iron-binding protein in milk and body secretions. The amino acid sequence of LTF consists of two homologous domains homologous to proteins in the transferrin family. Recent isolation of cDNA encoding mouse LTF has expedited the mapping of both mouse and human LTF genes. Southern blot analysis of DNA from mouse-Chinese hamster and human-mouse somatic cell hybrids maps the LTF gene to mouse chromosome 9 and to human chromosome 3, respectively. Furthermore, analysis of cell hybrids containing defined segments of human chromosome 3 demonstrates that the gene is located in the 3q21-qter region. These results suggest that LTF and associated genes of the transferrin family have existed together on the same chromosomal region for 300–500 million years.     

Crucial function of the pre-T-cell receptor (TCR) in TCRP selection, TCRβ allelic exclusion and αβ versus γδ lineage commitment

Summary: The analysis of T-cell receptor (TCR) βselection, TCRβ allelic exclusion and TCRβ rearrangement in γδ T cells from normal and pre-TCR-deficient mice has shown that the pre-TCR has a crucial role in T-lyinpbocyte development:

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  The pre-TCR is by far the most effective receptor that generates large numbers of CD4⁺8⁺ T cells with productive TCRβ rearrangements.
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  In the absence of the pre-TCR, TCRβ rearrangement proceeds in developing cells irrespective of whether they already contain a productive TCRβ gene.
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  The pre-TCR directs developing T cells to the αβ lineage because y5 T cells from pTα^-/- mice proceed much further in TCRβ rearrangement than γδ T cells from wild-type mice. It is argued that the pre-TCR commits developing T cells to the αβ lineage by an instructive mechanism, which has largely replaced an evolutionarily more ancient mechanism that involves stochastic αβ lineage commitment.

     

Assignment of the human gene for δ aminolevulinate dehydrase to chromosome 9 by somatic cell hybridization and specific enzyme immunoassay

A non-competitive enzyme immunoassay specific for δ aminolevulinate dehydrase has been devised and applied to rodent–human hybrid cell lines. Two different conditions have been used, one specific for the human enzyme and the other indicative of both rodent and human enzymes. The ratio of the values obtained under the two conditions was used to discriminate between positive and negative clones. By this method the gene for ALA dehydrase has been assigned to chromosome 9.