Regional assignment of arylsulfatase A,mitochondrial aconitase and NADH-cytochrome b5 reductase by somatic cell hybridization

Summary By using somatic cell hybrids between HPRT deficient hamster cells and fibroblasts derived from a patient with a X/22 translocation t(X;22)(q13;q112), we have assigned the genes for human ARSA, DIA 1, and ACO 2 to region q112qter of human chromosome 22 and the gene for human PGK close to the breakpoint in band Xq13.     

The human thyroglobulin gene: A polymorphic marker localized distal to C-MYC on chromosome 8 band q24

Summary We have used a cDNA clone for human phosphoglycerate kinase (PGK) to examine the chromosomal localization of three members of the human PGK gene family. Using somatic cell hybrids segregating portions of several X-autosome translocations as well as a clone panel of hybrids segregating radiation-induced fragments of the human X chromosome, we assign a PGK pseudogene to the region Xq11–Xq13, proximal to the functional X-linked PGK gene located in Xq13. In addition, using a panel of 24 somatic cell hybrids, we assign an autosomal PGK-related DNA sequence to human chromosome 19.     

Mapping of aminoacylase-1 and beta-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 beta-galactosidase-A (GLB1, E.C.3.2.1.23), deficient in GM1-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 leads to 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 beta-galactosidase locus. These data suggest that there is a region of homology within the p21 leads to 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 beta-galactosidase loci, we predict that the human transferrin (TF) gene is on chromosome 3.     

Assignment of the gene (RLBP1) for cellular retinaldehyde-binding protein (CRALBP) to human chromosome 15q26 and mouse chromosome 7.

Cellular retinaldehyde-binding protein (CRALBP) has properties that suggest that it is involved in the visual process and, therefore, potentially with retinal diseases. A human cDNA probe has been used to map this gene to human chromosome 15q26 (somatic cell hybrids and in situ hybridization) and to mouse chromosome 7 by somatic cell hybrids.     

The pronatriodilatin gene is located on the distal short arm of human chromosome 1 and on mouse chromosome 4.

Atrial natriuretic factors (ANF) are polypeptides having natriuretic, diuretic, and smooth muscle-relaxing activities that are synthesized from a single larger precursor: pronatriodilatin. Chromosomal assignment of the gene coding for human pronatriodilatin was accomplished by in situ hybridization of a [3H]-labeled pronatriodilatin probe to human chromosome preparations and by Southern blot analysis of somatic cell hybrid DNAs with normal and rearranged chromosomes 1. The human pronatriodilatin gene was mapped to the distal short arm of chromosome 1, in band 1p36. Southern blot analysis of mouse X Chinese hamster somatic cell hybrids was used to assign the mouse pronatriodilatin gene to chromosome 4. This assignment adds another locus to the conserved syntenic group of homologous genes located on the distal half of the short arm of human chromosome 1 and on mouse chromosome 4.     

The genes for the highly homologous Ca(2+)-binding proteins oncomodulin and parvalbumin are not linked in the human genome.

The chromosomal loci of the human parvalbumin and oncomodulin single-copy genes that encode structurally and evolutionarily closely related Ca(2+)-binding proteins were determined by somatic cell hybrid analysis. Southern blot analysis of genomic DNA from 25 human-hamster somatic cell hybrids showed that the human gene for oncomodulin resides on chromosome 7. Analysis of human-mouse hybrids selectively retaining human chromosome 7 or a portion of it allowed specific assignment of the gene locus to the p11-p13 region of chromosome 7 known to be mutated or deleted in patients with the Greig cephalopolysyndactyly syndrome. By gene dosage analysis on Southern blots, we showed that the gene for human parvalbumin maps distally to the cat eye syndrome marker D22S9 on chromosome 22q. Using somatic cell hybrids containing parts of human chromosome 22, the parvalbumin gene was sublocalized to the region 22q12-q13.1. This region contains a linkage group that maps to mouse chromosome 15, region E, and includes the SIS, ARSA, and DIA 1 genes. Our findings are consistent with the recent localization of the mouse parvalbumin gene to this region by two independent methods (C. H. Zühlke et al., 1989, Genet. Res. 54:37-43; S. Adolph et al., 1989, Cytogenet. Cell Genet. 52:177-179).     

Assignment of the human intestinal Na+/glucose cotransporter gene (SGLT1) to the q11.2----qter region of chromosome 22

The chromosomal location of the human intestinal Na+/glucose cotransporter gene (SGLT1) was determined using human cDNA and genomic probes for this transporter gene. Southern blot analysis of genomic DNA from 15 mouse-human somatic cell hybrids showed that the human gene for this transporter resides on chromosome 22. Analysis of hamster-human hybrids selectively retaining chromosome 22 or a portion of it allowed specific assignment of the locus to the q11.2----qter region of chromosome 22. A restriction fragment length polymorphism was identified with EcoRI.     

Isolation of anonymous,polymorphic DNA fragments from human chromosome 22q12-qter

Summary A series of 195 random chromosome 22-specific probes, equivalent to approximately 1% of the size of this chromosome, have been isolated from a chromosome 22-specific bacteriophage lambda genomic library. These probes were mapped to four different regions of chromosome 22 on a panel of five somatic cell hybrids. Restriction fragment length polymorphisms were detected by 28 of the probes mapping to 22q12-qter. Evolutionarily conserved sequences in human, mouse, and Chinese hamster DNA were detected by 12% of the isolated probes.     

The terminal deoxynucleotidyltransferase gene is located on human chromosome 10 (10q23----q24) and on mouse chromosome 19

Terminal deoxynucleotidyltransferase (TdT) is a DNA polymerase expressed in immature lymphocytes of the thymus and bone marrow, as well as certain leukemic cells. Chromosomal assignment of the gene coding for human TdT was accomplished by in situ hybridization of a 3H-labeled cDNA probe to human chromosome preparations and by Southern blot analysis of somatic cell hybrid DNAs. The human TdT gene was mapped to the region q23----q24 of chromosome 10. Breaks at this site have been reported in different translocations in human leukemias. The mouse TdT gene was assigned to chromosome 19 by Southern blot analysis of mouse X Chinese hamster somatic cell hybrids. This result adds a fourth locus to the conserved syntenic group on mouse chromosome 19 and human chromosome 10.     

Regional localization of the human platelet-derived endothelial cell growth factor (ECGF1) gene to chromosome 22q13.

Using in situ hybridization and a panel of human X rodent somatic cell hybrids, which discriminates between four different regions of human chromosome 22, we have localized the gene for human platelet-derived endothelial cell growth factor (ECGF1) to 22q13, placing ECGF1 distal to the PDGFB locus at 22q12.3----q13.1.     

The human catechol-O-methyltransferase (COMT) gene maps to band q11.2 of chromosome 22 and shows a frequent RFLP with BglI.

We have been able to assign the human catechol-O-methyltransferase gene (COMT) to chromosome 22q11.2 by using Southern blot analysis of panels of somatic cell hybrids and chromosomal in situ hybridization. Furthermore, Southern blot analysis of DNA from blood and bone marrow samples of a patient with chronic myeloid leukemia (CML), having an extra Philadelphia chromosome (Ph1) in addition to the one produced by the reciprocal translocation between chromosomes 9 and 22, showed increased COMT and BCR gene dosage as compared to DNAs originating from CML patients with only one Ph1 chromosome or from chromosomally normal individuals. Control hybridizations of the same blot with TCRG- and TCRA-specific probes showed corresponding signal intensities in all samples. A relatively frequent two-allele COMT gene RFLP (PIC = 0.37) was recognized in DNAs digested with BglI. Our gene mapping result is in concordance with that previously reported by Brahe et al. (1986), who used an autoradiozymogram assay on different somatic cell hybrids to map this gene to chromosome 22.     

Localization of the photoreceptor gene ROM1 to human chromosome 11 and mouse chromosome 19: sublocalization to human 11q13 between PGA and PYGM.

Rom-1 is a retinal integral membrane protein that, together with the product of the human retinal degeneration slow gene (RDS), defines a photoreceptor-specific protein family. The gene for rom-1 (HGM symbol: ROM1) has been assigned to human chromosome 11 and mouse chromosome 19 by Southern blot analysis of somatic cell hybrid DNAs. ROM1 was regionally sublocalized to human 11p13-11q13 by using three mouse-human somatic cell hybrids; in situ hybridization refined the sublocalization to human 11q13. Analysis of somatic cell hybrids suggested that the most likely localization of ROM1 is in the approximately 2-cM interval between human PGA (human pepsinogen A) and PYGM (muscle glycogen phosphorylase). ROM1 appears to be a new member of a conserved syntenic group whose members include such genes as CD5, CD20, and OSBP (oxysterol-binding protein), on human chromosome 11 and mouse chromosome 19. Localization of the ROM1 gene will permit the examination of its linkage to hereditary retinopathies in man and mouse.     

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.     

The gene for the cell adhesion molecule M-cadherin maps to mouse chromosome 8 and human chromosome 16q24.1-qter and is near the E-cadherin (uvomorulin) locus in both species.

A mouse myotube-derived cDNA encoding the Ca(2+)-dependent cell adhesion molecule M-cadherin was used to study the segregation of the corresponding gene Cdh3 in a mouse interspecific backcross. Cdh3 was found to be unlinked to the N-cadherin gene but linked to the E-cadherin (uvomorulin) locus on chromosome 8 in a region of conserved synteny with human chromosome 16q. The gene order cen-Junb-Um-Tat-(Cdh3/Aprt) was determined. The human homologue CDH3 was mapped to chromosome 16q24.1-qter by analyzing human/mouse somatic cell hybrids.     

Assignment of the human fast skeletal muscle myosin alkali light chains gene (MLC1F/MLC3F) to 2q 32.1-2qter

Summary A DNA probe derived from a mouse intronless pseudogene including coding regions for the myosin fast skeletal muscle alkali light chains, MLC1_F/MLC3_F (suggested HGM symbol, MYL1), was tested on a panel of 25 independent man-rodent somatic cell hybrids in order to assign the human MLC1_F/MLC3_F gene to a human chromosome. A 3.7-kb TaqI human fragment was found to correlate with the presence of chromosome 2 in the hybrids, characterized both by cytogenetic analysis and reference enzyme markers. A regional assignment to 2q32.1-qter was possible using hybrids whose human parental strains bore a reciprocal translocation t(X;2) (p22;q32.1). The fact that IDH1 and the MLC1_F/MLC3_F gene are closely linked on chromosome 1 in the mouse and map to the same region of human chromosome 2 in man indicates, that these chromosomes have a conserved region of homology between them and that the human 3.7-kb TaqI fragment corresponds indeed to a functional gene.     

Assignment of the structural genes for the alpha subunit of hexosaminidase A, mannosephosphate isomerase, and pyruvate kinase to the region q22-qter of human chromosome 15.

Concordant segregation of the expression of the alpha subunit of human hexosaminidase A, human mannosephosphate isomerase, and pyruvate kinase was observed in somatic cell hybrids between either thymidine kinase-deficient mouse cells or thymidine kinase-deficient Chinese hamster cells and human white blood cells carrying a translocation of the distal half (q 22-qter) of the long arm of chromosome 15 to chromosome 17. A positive correlation was established between the expression of these human phenotypes and the presence of the distal half of the long arm of human chromosome 15.     

Pro-melanin-concentrating hormone gene (PMCH) is localized on human chromosome 12q and rat chromosome 7

Melanin-concentrating hormone (MCH) is a cyclic neuropeptide that may be involved in regulation of the stress response and food intake behavior in mammals. MCH and two other putative neuropeptides, NEI and NGE, are encoded by the same precursor, designated pro-melanin-concentrating hormone (PMCH). A panel of somatic cell hybrids segregating either human or rat chromosomes was used to determine the chromosomal localization of the PMCH locus. It was assigned to human chromosome 12q and to rat chromosome 7. This is the first neuropeptide-encoding gene found in this new synteny group conserved in rat and human.     

Regional assignment of the mouse alpha A2-crystallin gene (Crya-1) to chromosome 17A3----B by in situ hybridization

Previously, we assigned the alpha A2-crystallin (Crya-1) structural gene to mouse chromosome 17 via Southern blot hybridization analysis of mouse x Chinese hamster somatic cell hybrids. Using in situ hybridization, we have now localized this gene to 17A3----B, a subchromosomal region containing several genes whose linkage relationships have been shown to be conserved on human chromosome 6. In man, however, the homologous gene (CRYA1) is located on human chromosome 21, indicating that internal rearrangements can occur within highly conserved chromosomal regions during the divergence of man and mouse.     

The human aminopeptidase N gene: isolation,chromosome localization,and DNA polymorphism analysis

Summary DNA encoding the human aminopeptidase N (EC 3.4.11.2) gene (PEPN) was first isolated using rat cDNA probes and then used in Southern analysis of DNA from mouse-human somatic cell hybrids to assign this gene to the long-arm region (q11-qter) of human chromosome 15. This human genomic DNA probe detects a frequent DraIII polymorphism that is a useful marker for human chromosome 15.     

Localization of the human GM-CSF receptor beta chain gene (CSF2RB) to chromosome 22q12.2-->q13.1.

The gene for the beta-chain of the human GM-CSF receptor (CSF2RB) has been mapped to chromosome 22 by PCR analysis of a series of human x rodent somatic cell hybrids. In situ hybridization to normal human chromosomes and two translocations involving chromosome 22 and the chromosome expressing the rare fragile site FRA22A place the gene in the region 22q12.2-->q13.1, proximal to the fragile site.