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).     

Regional assignment of the erythropoietin gene to human chromosome region 7pter----q22

The chromosomal location of the human gene for erythropoietin (EPO) was determined by Southern blot hybridization analysis of a panel of human-mouse somatic hybrid cell DNAs. DNAs from cell hybrids containing reduced numbers of human chromosomes were treated with the restriction enzyme PstI and screened with a cloned human EPO cDNA probe. EPO is assigned to human chromosome 7 based on the complete cosegregation of EPO with this chromosome in all 45 cell hybrids tested. A cell hybrid containing a translocated derivative of chromosome 7 localizes EPO to 7pter----q22. A HindIII restriction fragment length polymorphism is detected by hybridization of the EPO cDNA probe to human genomic DNA.     

Assignment of the gene coding for human peroxisomal 3-oxoacyl-CoA thiolase (ACAA) to chromosome region 3p22----p23

The chromosomal location of the human gene coding for peroxisomal 3-oxoacyl-CoA thiolase (ACAA) was determined with the aid of cDNA and genomic probes by screening of rodent x human somatic cell hybrids and in situ hybridization. The results localize the gene to chromosome region 3p22----p23.     

Assignment of the structural gene coding for albumin to human chromosome 4

Summary Albumin is a developmentally regulated serum protein synthesized in the liver mainly during adulthood. Family studies using variant forms of albumin established autosomal linkage between albumin and group-specific component protein (GS). Since GC has been assigned to human chromosome 4, albumin can be indirectly assigned to the same chromosome; however no direct assignment has been made. Recently, the human albumin cDNA probe has been isolated and characterized. It thus permits a direct chromosomal assignment of the albumin gene in the human genome. When the cDNA probe was hybridized to the HindIII digested total human DNA, an intense band at 6.8 kb was present. When the probe was hybridized to the HindIII digested Chinese hamster CHO-K1 DNA, a less intense band at 3.5 kb was found, plus three other faint bands. When the probe was hybridized to a series of human/CHO-K1 cell hybrids retaining a complete hamster genome and various combinations of human chromosomes, it was evident that hybrids containing human albumin gene sequences could be readily distinguished from hybrids containing no human albumin gene. Analysis of 22 primary cell hybrids for the presence or absence of human albumin sequences has assigned the albumin gene to human chromosome 4. Similar results were obtained using another restriction endonuclease EcoR1. Thus, by direct assay of the genomic albumin gene sequences in the cell hybrids, we provide evidence for a direct assignment of the structural gene for human albumin to chromosome 4.     

The human myoglobin gene: a third dispersed globin locus in the human genome.

Human myoglobin is specified by a single gene. Unique sequence DNA probes were isolated from the cloned gene and used to test for the presence of the human myoglobin gene in a series of human rodent somatic cell hybrids containing various complements of human chromosomes. The myoglobin gene cosegregated with human chromosome 22. Somatic cell hybrids containing translocation chromosomes carrying part of chromosome 22 were used to locate the myoglobin gene to the region 22q11----22q13. The myoglobin gene is therefore not linked to the alpha-globin gene cluster on chromosome 16 or the beta-globin cluster on chromosome 11, and represents a third dispersed globin locus in the human genome.     

Mapping the human acetylcholinesterase gene to chromosome 7q22 by fluorescent in situ hybridization coupled with selective PCR amplification from a somatic hybrid cell panel and chromosome-sorted DNA libraries

To establish the chromosomal location of the human ACHE gene encoding the acetylcholine hydrolyzing enzyme acetylcholinesterase (ACHE, acetylcholine acetylhydrolase, E.C. 3.1.1.7), a human-specific polymerase chain reaction (PCR) procedure that supports the selective amplification of ACHE DNA fragments from human genomic DNA was employed with 19 human-hamster somatic cell hybrids carrying one or more human chromosomes. Informative ACHE-specific PCR fragments were produced from two cell lines, both of which include human chromosome 7, but not with DNA from 17 cell hybrids carrying various combinations of all human chromosomes other than 7. Fluorescent in situ hybridization of biotinylated ACHE DNA with metaphase chromosomes from human peripheral blood lymphocytes revealed prominent labeling on the 7q22 position. Therefore, further tests were performed to confirm the chromosome 7 location. DNA samples from the two cell lines including chromosome 7 and the ACHE gene were positive with PCR primers informative for the human cystic fibrosis CFTR gene, known to reside at the 7q31.1 position, but negative for the ACHE-related butyrylcholinesterase (BCHE, acylcholine acylhydrolase, E.C. 3.1.1.8) gene, mapped at the 3q26-ter position, confirming that these lines contain chromosome 7 but not chromosome 3. In contrast, three other cell lines including chromosome 3, but not 7, were BCHE-positive and ACHE-negative. In addition, genomic DNA from a sorted chromosome 7 library supported the production of ACHE- but not BCHE-specific PCR products, whereas with DNA from a sorted chromosome 3 library, the BCHE but not the ACHE fragment was amplified. These findings assign the human ACHE gene to a single locus on chromosome 7q22 and should assist in establishing linkage between the in vivo amplification of the ACHE gene in ovarian tumors and leukemias and the phenomenon of tumor-related breakage in the long arm of chromosome 7.     

Mapping of the versican proteoglycan gene (CSPG2) to the long arm of human chromosome 5 (5q12-5q14).

Versican is a major chondroitin sulfate proteoglycan of vascularized connective tissues whose eponym reflects its functional versatility in macromolecular affinity and interactions. In this report we have localized the versican gene (CSPG2) to the long arm of human chromosome 5 by utilizing a combination of somatic cell hybrids, Southern blotting, polymerase chain reaction, and chromosomal in situ hybridization. The proteoglycan gene segregated concordantly with hybrid cell lines containing the long arm of chromosome 5, comprising the 5q12-q14 band regions. To refine this locus further, we screened a chromosome 5-specific library and isolated several genomic clones encoding a portion of the 5' end of versican. One of these genomic clones was used as a probe for in situ hybridization of human chromosome metaphases. The results corroborated the data obtained using somatic cell hybrids and further refined the assignment of the versican gene to the narrow band region of 5q12-5q14, with the primary site likely to be 5q13.2. The availability of novel genomic clones and the mapping data presented here will make possible the identification of any defect genetically linked to this proteoglycan gene.     

Mapping the human acetylcholinesterase gene to chromosome 7q22 by fluorescent in situ hybridization coupled with selective PCR amplification from a somatic hybrid cell panel and chromosome-sorted DNA libraries.

To establish the chromosomal location of the human ACHE gene encoding the acetylcholine hydrolyzing enzyme acetylcholinesterase (ACHE, acetylcholine acetylhydrolase, E.C. 3.1.1.7), a human-specific polymerase chain reaction (PCR) procedure that supports the selective amplification of ACHE DNA fragments from human genomic DNA was employed with 19 human-hamster somatic cell hybrids carrying one or more human chromosomes. Informative ACHE-specific PCR fragments were produced from two cell lines, both of which include human chromosome 7, but not with DNA from 17 cell hybrids carrying various combinations of all human chromosomes other than 7. Fluorescent in situ hybridization of biotinylated ACHE DNA with metaphase chromosomes from human peripheral blood lymphocytes revealed prominent labeling on the 7q22 position. Therefore, further tests were performed to confirm the chromosome 7 location. DNA samples from the two cell lines including chromosome 7 and the ACHE gene were positive with PCR primers informative for the human cystic fibrosis CFTR gene, known to reside at the 7q31.1 position, but negative for the ACHE-related butyrylcholinesterase (BCHE, acylcholine acylhydrolase, E.C. 3.1.1.8) gene, mapped at the 3q26-ter position, confirming that these lines contain chromosome 7 but not chromosome 3. In contrast, three other cell lines including chromosome 3, but not 7, were BCHE-positive and ACHE-negative. In addition, genomic DNA from a sorted chromosome 7 library supported the production of ACHE- but not BCHE-specific PCR products, whereas with DNA from a sorted chromosome 3 library, the BCHE but not the ACHE fragment was amplified.(ABSTRACT TRUNCATED AT 250 WORDS)     

Localization of the cellular retinoic acid binding protein (CRABP) gene relative to the acute promyelocytic leukemia-associated breakpoint on human chromosome 15

Summary A human genomic fragment comprising the cellular retinoic acid binding protein (CRABP) gene was isolated. By using a panel of somatic cell hybrids, this gene could be assigned to human chromosome 15. Subsequently, a possible involvement of the CRABP gene in translocation (15;17) (q22;q11) positive acute promyelocytic leukemia (APL) was investigated. Although transposition of the CRABP gene could be demonstrated, we did not observe any gross CRABP rearrangement in a series of primary APL patients, nor in the acute myeloblastic leukemia cell line HL-60. Thus, the observed lack of CRABP expression in these leukemic cells may not be caused by disruption of its gene. CRABP maps to the region 15q22-qter.     

The human mitochondrial citrate transporter gene (SLC20A3) maps to chromosome band 22q11 within a region implicated in DiGeorge syndrome,velo-cardio-facial syndrome and schizophrenia

The gene encoding the human mitochondrial citrate transporter designated SLC20A3 was mapped to chromosome 22 by analyzing its segregation in a panel of human-hamster somatic cell hybrids. This assignment was confirmed by fluorescence in situ hybridization to metaphase chromosomes, and the gene was further localized to band 22q11.21. The gene is located in a critical region associated with allelic losses in a variety of clinical syndromes, including DiGeorge syndrome, velo-cardio-facial syndrome and a subtype of schizophrenia. Received: 20 November 1995 / Revised: 4 January 1996     

Isolation and mapping of cosmid markers on human chromosome 22, including one within the submicroscopically deleted region of DiGeorge syndrome

A genomic cosmid library was constructed from a Chinese hamster/human hybrid cell containing human intact chromosome 22 as its only human component. Of 1000 cosmids with inserts derived from human chromosome 22, 191 were tested for restriction fragment length polymorphisms (RFLPs). As a result, 64 clones detected RFLPs, including five variable number of tandem repeats systems. Of the remaining 127 cosmids, 111 detected a single copy sequence on human chromosome 22. Five somatic cell hybrids allowed us to assign all of the 64 polymorphic cosmids and 44 non-polymorphic cosmids to four different regions of human chromosome 22. In two patients with DiGeorge syndrome, one of the cosmids that had been sublocalized to 22pter-q11 detected hemizygosity. These 108 cosmid markers regionally assigned to human chromosome 22 should be useful for the construction of long-range physical maps and the identification of genetic alterations on the chromosome.     

Regional localization and molecular characterization of a DNA sequence on the long arm of chromosome 22

Summary A human genomic DNA fragment, p22hom13 (D22S16), was isolated from a chromosome 22-specific library. After elimination of repetitive sequences, a single copy BamHI-EcoRI fragment was subcloned into pTZ18. By using mouse/human somatic cell hybrids and in situ hybridization, the new DNA probe was mapped to chromosome 22q13-qter. Its application in the analysis of the distal part of chromosome 22 and its diagnostic use in translocations are discussed.     

The human connexin gene family of gap junction proteins: distinct chromosomal locations but similar structures.

Connexins are protein subunits that constitute gap junction channels. Two members of this gene family, connexin43 (Cx43) and connexin32 (Cx32), are abundantly expressed in the heart and liver, respectively. Human genomic DNA analysis revealed the presence of two loci for Cx43: an expressed gene and a processed pseudogene. The expressed gene (GJA1) was mapped to human chromosome 6 and the pseudogene (GJA1P) to chromosome 5. To determine whether Cx32 was linked to Cx43, somatic cell hybrids were analyzed by polymerase chain reaction and hybridization, resulting in the assignment of the gene for Cx32 (GJB1) to the X chromosome at Xp11----q22. Comparison of the structures of connexin genes suggests that members of this multigene family arose from a single precursor, but evolved to distinct chromosomal locations.     

Human genes involved in lipolysis of plasma lipoproteins: mapping of loci for lipoprotein lipase to 8p22 and hepatic lipase to 15q21

We have used cDNA probes for lipoprotein lipase and hepatic lipase to determine the chromosomal and subchromosomal locations of the human genes for these lipolytic enzymes. Southern blot analysis of genomic DNA from 17 independent mouse-human somatic cell hybrids demonstrated the presence of the gene for human lipoprotein lipase on chromosome 8, whereas the gene for hepatic lipase was on chromosome 15. Regional mapping of the genes by in situ hybridization to human chromosomes indicated that the lipoprotein lipase gene (LPL) resides in the p22 region of chromosome 8, while hepatic lipase gene (HL) resides in the q21 region of chromosome 15. We previously reported, on the basis of nucleotide and amino acid homologies, that these genes are members of a gene family of lipases, and, thus, the present findings indicate that the members of this family are dispersed. The results are also of significance with respect to disorders involving deficiencies of the enzymes. In particular, they suggest that certain rare combined deficiencies of both enzymes do not involve mutations of the structural loci.     

Chromosomal distribution of three members of the human natriuretic peptide receptor/guanylyl cyclase gene family

Chromosomal localization of the genes encoding three homologous human proteins, the ANPRA, ANPRB, and ANPRC cell surface receptors, was determined by polymerase chain reaction (PCR) analysis of genomic DNA from somatic cell hybrids. The ANPRA gene was assigned to 1q12----qter by intron-specific PCR. The ANPRB gene was assigned to 9p11----p22 using species-specific length variation in PCR fragments. The ANPRC gene was assigned to chromosome 5 using human-specific PCR primers identified by screening a human primer panel on parental DNA samples (shotgun primer screening). Chromosomal assignments based on PCR analysis were confirmed and the genes further sublocalized by in situ hybridization of cloned cDNA probes to human metaphase chromosomes. The ANPRA gene was sublocalized to 1q21----q22, the ANPRB gene to 9p12----p21, and the ANPRC gene to 5p13----p14.     

Regional localization of the gene for thyroid peroxidase to human chromosome 2pter----p12

A 2.0-kb thyroid peroxidase cDNA of human origin was used as probe for Southern blot hybridization of genomic DNA from human somatic cells and human-rodent somatic cell hybrids. The results showed that the gene coding for human thyroid peroxidase is located on chromosome. 2. Further analysis of hybrids derived from Burkitt lymphoma cells carrying a (2;8)(p12;q24) translocation revealed that the gene maps to the region 2pter----p12.     

Assignment of the functional gene for human adrenodoxin to chromosome 11q13----qter and of adrenodoxin pseudogenes to chromosome 20cen----q13.1.

Adrenodoxin is a small iron/sulfur protein serving as an electron-transport intermediate for all mitochondrial forms of cytochrome P450. Southern blots of normal genomic DNA cleaved with six restriction endonucleases probed with full-length human adrenodoxin cDNA revealed complex patterns indicating the presence of multiple adrenodoxin genes. Southern blots of DNA from a panel of mouse/human somatic cell hybrids identified cross-hybridizing adrenodoxin DNA in two loci, chromosome 11q13----qter and chromosome 20cen----q13.1. Examination of adrenodoxin clones from a genomic DNA library in phage lambda revealed some clones bearing gene fragments interrupted by introns and other clones bearing processed pseudogenes. By probing the mouse/human hybrids with unique intronic DNA and by correlating restriction maps of the phage clones with that of uncloned genomic DNA, we show that the authentic transcribed adrenodoxin gene lies on chromosome 11, while pseudogenes lie on chromosome 20.     

Localization of the gene encoding human erythroid-potentiating activity to chromosome region Xp11.1----Xp11.4.

We have localized the human gene for erythroid potentiating activity (EPA) to the X chromosome by analysis of its segregation pattern in mouse-human somatic cell hybrids. The EPA gene has been further localized to human chromosome region Xp11.1----Xp11.4 by in situ hybridization of a molecularly cloned EPA genomic fragment to metaphase chromosomes.     

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.     

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.