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C M Disteche

Publications and source records attributed to C M Disteche.

At least 55 records · Page 3Linked to original sources
PubMed1996

Recurrent duplication and deletion polymorphisms on the long arm of the Y chromosome in normal males.

Deletion of the 50f2/C (DYS7C) locus in interval 6 of Yq has previously been reported as a polymorphism in three males. We describe a survey of worldwide populations for further instances of this deletion. Of 859 males tested, 55 (approximately 6%) show absence of the 50f2/C locus; duplication of the locus was also detected in eight out of 595 males (approximately 1.4%). Populations having the deletion are confined to Asia, Australasia, and southern and northern Europe; of those of reasonable sample size, Finns had the highest deletion frequency (55%; n = 21). The deletions vary in size and the larger ones remove some of the RBM (RNA Binding Motif) genes, but none of the deletion males lack DAZ (Deleted in AZoospermia), a candidate gene for the azoospermia factor. On a tree of Y haplotypes, 28 deletion and eight duplication chromosomes fall into six and four haplotypic groups respectively, each of which is likely to represent an independent deletion or duplication event. Microsatellite and other haplotyping data suggest the existence of at least two further classes of deletion. Thus duplications and deletions in this region of Yq have occurred many times in human evolution, but remain useful markers for paternal lineages.

Asia↗
PubMed1996

Human huntingtin derived from YAC transgenes compensates for loss of murine huntingtin by rescue of the embryonic lethal phenotype.

Huntington disease (HD) is caused by expansion of a CAG trinucleotide repeat in exon 1 of a novel gene. The HD protein (huntingtin) plays a critical role in early embryonic development since homozygous targeted disruption of the murine HD gene results in embryonic lethality by day 7.5. To rescue this phenotype by transgene based huntingtin expression it is therefore essential to express the protein early enough in development in the appropriate cells. Since YAC based transgenes are known to be regulated in an appropriate temporal and tissue-specific manner, we sought to rescue the embryonic lethality by breeding YAC transgenic mice expressing human huntingtin with mice heterozygous for the targeted disruption. We generated viable offspring homozygous for the disrupted murine HD gene but expressing human huntingtin derived from the YAC. This result clearly shows that YAC transgene based expression of huntingtin occurs prior to 7.5 days gestation. Additionally, we show that human huntingtin expression in YAC transgenic mice follows an identical tissue distribution and subcellular localisation pattern as that of the murine endogenous protein and that expression levels of 2-3 times endogenous can be achieved. This shows that human huntingtin under the influence of its native promoter, despite differences to the murine protein, is functional in a murine background and can compensate for loss of the murine protein. These results show that YAC transgenic approaches are a particularly promising route to producing an animal model for disorders associated with CAG expansion.

Animals↗
PubMed1996

Cloning and characterization of rat density-enhanced phosphatase-1, a protein tyrosine phosphatase expressed by vascular cells.

We have cloned from cultured vascular smooth muscle cells a protein tyrosine phosphatase, rat density-enhanced phosphatase-1 (rDEP-1), which is a probable rat homologue of DEP-1/HPTP eta. rDEP-1 is encoded by an 8.7-kb transcript and is expressed as a 180- to 220-kD protein. The rDEP-1 gene is located on human chromosome 11 (region p11.2) and on mouse chromosome 2 (region 2E). The cDNA sequence predicts a transmembrane protein consisting of a single phosphatase catalytic domain in the intracellular region, a single transmembrane domain, and eight fibronectin type III repeats in the extracellular region (GenBank accession number U40790). In situ hybridization analysis demonstrates that rDEP-1 is widely expressed in vivo but that expression is highest in cells that form epithelioid monolayers. In cultured cells with epitheliod morphology, including endothelial cells and newborn smooth muscle cells, but not in fibroblast-like cells, rDEP-1 transcript levels are dramatically upregulated as population density increases. In vivo, quiescent endothelial cells in normal arteries express relatively high levels of rDEP-1. During repair of vascular injury, expression of rDEP-1 is downregulated in migrating and proliferating endothelial cells. In vivo, rDEP-1 transcript levels are present in very high levels in megakaryocytes, and circulating plates have high levels of the rDEP-1 protein. In vitro, initiation of differentiation of the human megakaryoblastic cell line CHRF-288-11 with phorbol 12-myristate 13-acetate leads to a very strong upregulation of rDEP-1 transcripts. The deduced structure and the regulation of expression of rDEP-1 suggest that it may play a role in adhesion and/or signaling events involving cell-cell and cell-matrix contact.

Amino Acid Sequence↗
PubMed1995

Human platelet glycoproteins V and IX: mapping of two leucine-rich glycoprotein genes to chromosome 3 and analysis of structures.

Human platelet glycoproteins Ib alpha, Ib beta, V, and IX comprise an interrelated set of molecules (the Ib-V-IX system) that together form a surface adhesion receptor for the ligand, von Willebrand factor. To complete the primary structural characterization of the genes involved in this system, we have analyzed cosmid clones for both the glycoprotein V and IX genes and used these clones to localize the two genes by fluorescence in situ hybridization. Both genes were found on the long arm of chromosome 3, but at distinct sites, the GPV gene on 3 band q29 and the GP IX gene on 3 band q21. The transcriptional start site of the GPV gene was defined by "anchored" PCR and primer extension. The GPV gene contains two exons, the first consisting of approximately 37 bases and the second of approximately 3500 bases, interrupted by a single 958 base intron. The GPV transcript has multiple start sites spread over a twenty base region. The 5' flanking region of the GPV gene has a series of potential consensus regulatory elements including GATA, ets, and Sp-1 sites, similar to those found in other described megakaryocyte/platelet genes, including those of the Ib-V-IX system. In assessing the four Ib-V-IX genes as a group, all four have a simple, "intron-depleted" structure with the entire open reading frame of the mature polypeptide located within a single exon.(ABSTRACT TRUNCATED AT 250 WORDS)

Base Sequence↗
PubMed1995

Mapping of the NEP receptor tyrosine kinase gene to human chromosome 6p21.3 and mouse chromosome 17C.

The mouse receptor tyrosine kinase (RTK) NEP, also called Ptk-3, is widely expressed, with high levels in proliferating neuroepithelia of mouse embryos. The recently described human discoidin domain receptor (DDR) has a predicted amino acid sequence 93% identical to that of murine NEP and may be its human homologue. We have mapped the gene encoding NEP in human and mouse by fluorescence in situ hybridization using a mouse cDNA probe. The NEP/Nep gene maps to human chromosome 6p21.3 and mouse chromosome 17C, respectively. This places the NEP/Nep gene at, or near, the major histocompatibility (MHC) locus--HLA in human and H2 in mouse, respectively. Based on its pattern of expression during development, NEP and Nep represent candidate genes for several MHC-linked developmental abnormalities in human and mouse.

Animals↗
PubMed1995

In situ hybridization analysis of the Y chromosome in gonadoblastoma.

Gonadoblastoma is a rare tumor arising in the streak gonads of about 30% of 46,XY sex-reversed females. Because gonadoblastoma develops only in patients who have Y-chromosome material and dysgenetic gonads, it has been hypothesized that positive expression of a gene (or genes) on the Y chromosome (GBY) is involved in the etiology of the tumor. To examine the Y chromosome directly in tumors, we performed nonisotopic in situ hybridization of a biotin-labeled Y-specific probe for the DYZI locus on formalin-fixed, paraffin-embedded sections of tumor samples from four different patients. After hybridization to DYZI, the Y chromosome was found to be present in all gonadoblastoma foci in the four patients studied, and the gonadoblastoma foci showed an average of 85% cell nuclei positive for the Y chromosome on tissue sections. Normal male and female control tissues showed an average of 78% and 0% positive nuclei, respectively. One patient with bilateral gonadoblastoma had previously been shown to be mosaic, with a 45,X/46,XY karyotype in lymphocytes, skin fibroblasts, and cultures from both gonads. Examination of sections of this patient's gonads showed 79% positive nuclei within the gonadoblastoma foci, whereas the nontumor stromal tissue had 19% positive nuclei. These results indicate that, in this mosaic gonad, tumor foci developed only from cells that had a Y chromosome. Our results support the hypothesis that there is a GBY locus on the Y chromosome and that the Y chromosome is retained in the gonadoblastoma foci during the development of the tumor.

Adolescent↗
PubMed1995

Mapping of adenylyl cyclase genes type I, II, III, IV, V, and VI in mouse.

The adenylyl cyclases (AC) act as second messengers in regulatory processes in the central nervous system. They might be involved in the pathophysiology of diseases, but their biological function is unknown, except for AC type I, which has been implicated in learning and memory. We previously mapped the gene encoding AC I to human Chromosome (Chr) 7p12. In this study we report the mapping of the adenylyl cyclase genes type I-VI to mouse chromosomes by fluorescence in situ hybridization (FISH): Adcy1 to Chr 11A2, Adcy2 to 13C1, Adcy3 to 12A-B, Adcy4 to 14D3, Adcy5 to 16B5, and Adcy6 to 15F. We also confirmed previously reported mapping results of the corresponding human loci ADCY2, ADCY3, ADCY5, and ADCY6 to human chromosomes and, in addition, determined the chromosomal location of ADCY4 to human Chr 14q11.2. The mapping data confirm known areas of conservation between mouse and human chromosomes.

Adenylyl Cyclases↗
PubMed1995

The X-linked methylated DNA binding protein, Mecp2, is subject to X inactivation in the mouse.

DNA methylation at the promoter region of X-linked genes is associated with the maintenance of X inactivation in mammals. One of the methylated DNA binding proteins, MECP2, that binds to methylated bases in DNA is encoded by a gene (Mecp2) located on the mouse X Chromosome (Chr). To determine whether this gene was expressed from the inactive X Chr, and X-autosome translocation (T(X;16)16H) system in which expression from the Mecp2 allele on the inactive X Chr could be assayed was used. Results from these experiments indicate that Mecp2 is subject to X inactivation in mouse.

Animals↗
PubMed1995

Is the 15-in situ clone protocol necessary to detect amniotic fluid mosaicism?

OBJECTIVE: Our purpose was to evaluate the 15-clone analysis for detecting amniotic fluid mosaicism by the in situ method. STUDY DESIGN: A 10-year review was performed of all amniotic fluid mosaicism cases at two institutions using the in situ method exclusively, with sequential clonal analysis to determine the first and second clone in which the abnormal cell line occurred. RESULTS: Of the 28,497 amniotic fluid samples, 73 met criteria for amniotic fluid mosaicism by in situ method (0.26%). There were 54 cases (0.19%) with potential clinical significance (23 autosome and 31 sex chromosome mosaicism); 49 of the 54 cases (89%) were detected in the first six clones, including 22 of 23 involving autosomes and 27 of 31 involving sex chromosomes. In one of the six cases detected after clone 6 (46,XX/47,XX,+21) the mosaic cell line was present in 20% of the clones analyzed and was followed by a voluntary termination of the pregnancy. In the other five cases amniotic fluid mosaicism was present in < 20% of the clones; these included one case of 46,XX/47,XX+mar (15% amniotic fluid mosaicism, voluntary termination of pregnancy), two cases of 45,X/46,XY (10% to 12% amniotic fluid mosaicism, both normal at birth), and two cases of 45,X/46,XX (8% amniotic fluid mosaicism, lost to follow-up; 12% amniotic fluid mosaicism, voluntary termination of pregnancy). By limiting the analysis to six clones, approximately 20% of analysis time could be saved per case, but one autosomal amniotic fluid mosaicism case per 10,000 samples could potentially be missed. CONCLUSION: Reducing the number of clones analyzed by in situ method could result in increased efficiency, decreased costs, and minimal loss of sensitivity.

Amniotic Fluid↗
PubMed1995

Escape from X inactivation in human and mouse.

Genes that escape X inactivation have been recently found in human and in mouse. Although many of these genes have homologues on the Y chromosome that may compensate for expression from both X alleles in females, some have no Y homologues, and this presumably results in dosage differences between the sexes. Comparisons between human and mouse have revealed that the X-inactivation status of some genes differs significantly between the two species, suggesting continuous evolutionary changes in the sex chromosomes. Questions about the mechanisms of 'escape' are relevant to the understanding of gene regulation by X inactivation.

Alleles↗
PubMed1995

The mouse Sb1.8 gene located at the distal end of the X chromosome is subject to X inactivation.

The mouse homolog of the human DXS423E (SB1.8) gene has been isolated by screening a mouse cDNA library. Like its human counterpart, the mouse Sb1.8 gene is X-linked, as shown by Southern blot analysis and by in situ hybridization to metaphase chromosomes. Sb1.8 was sublocalized to band F of the mouse X chromosome, distal to Alas2 and proximal to DXPas1, which confirms a region of conservation between band Xp11.21-p11.22 in human and band XF in mouse. In situ hybridization also showed that the Smcx (Xe169) gene maps near Sb1.8 in band F. The Sb1.8 gene was shown to be highly conserved in mammals; partial DNA sequence analysis indicates 92% identity between the mouse and human genes. In contrast to the human DXS423E gene, the mouse Sb1.8 gene is subject to X inactivation, as shown by restriction enzyme and sequence analysis of mRNA from mice with Searle's translocation (T(X;16)16H). Absence of Sb1.8 expression from the inactive mouse X chromosome in vitro was confirmed by analysis of a cell line (Hobmski) in which the M. spretus X chromosome is inactivated. The Sb1.8 gene is a new member of a group of genes that escape X inactivation in human, but are inactivated in mouse.

Animals↗
PubMed1995

Gonadoblastoma: molecular definition of the susceptibility region on the Y chromosome.

Using sequence-tagged sites we have performed deletion mapping of the Y chromosome in sex-reversed female patients with a Y chromosome and gonadoblastoma. The GBY gene (gonadoblastoma locus on the Y chromosome) was sublocalized to a small region near the centromere of the Y chromosome. We estimate the size of the GBY critical region to be approximately 1-2 Mb. Our analysis also indicates that copies of two dispersed Y-linked gene families, TSPY (testis-specific protein, Y-encoded) and YRRM (Y-chromosome RNA recognition motif) are present in all patients and that copies of TSPY but not YRRM fall within the GBY critical region as formally defined by deletion mapping. Two tumor samples showed expression of both genes and in one patient this expression was limited to a unilateral gonadoblastoma but absent in the contralateral streak gonad. Although our results do not directly implicate TSPY or YRRM in the etiology of the tumor, they raise the issue of whether there is one GBY gene in the critical region or possibly multiple GBY loci dispersed on the Y chromosome.

Adolescent↗
PubMed1994

TCR selection and allelic exclusion in RAG transgenic mice that exhibit abnormal T cell localization in lymph nodes and lymphatics.

RAG-1 and RAG-2 are developmentally regulated genes that are essential for V(D)J recombination and lymphocyte development. Expression of RAG-1 and RAG-2 by thymocytes is normally limited to cells that have not completed selection. We have previously documented that persistent expression of the recombinase activating genes (RAG) in transgenic mice results in aberrant thymic development, altered lymphatic microanatomy, and a profound immunodeficiency. Here we further document the pathologic changes found in TG.RAG-1,2 mice and examine the role of TCR recombination and positive and negative thymic selection, as well as allelic exclusion, in the etiology of the phenotype. We find that neither selection nor TCR allelic exclusion can be overcome by transgenic expression RAG-1 and RAG-2 under the control of an lck promoter.

Alleles↗
PubMed1994

Characterization of the murine B7-1 genomic locus reveals an additional exon encoding an alternative cytoplasmic domain and a chromosomal location of chromosome 16, band B5.

The murine B7-1 (mB7-1) molecule expressed on APCs delivers a costimulatory signal for T cell activation through its T cell counter-receptor CD28, resulting in T cell proliferation and IL-2 production. Signaling through the TCR in the absence of CD28 signaling results in T cell anergy. We have analyzed the genomic structure of mB7-1 and here describe the identification of a previously unrecognized sixth exon at the far 3' end of the locus, which encodes an alternative cytoplasmic domain. Reverse transcriptase-PCR amplification of mB7-1 transcripts demonstrates that exon 6 is functionally spliced to the transmembrane-encoding exon 4. Furthermore, using 5' rapid amplification of cDNA ends, we determined that the 5'-untranslated region extends over 1505 bp beyond the previously reported transcriptional start site. In addition, we report the chromosomal location of mB7-1 to chromosome 16, band B5.

Alternative Splicing↗
PubMed1994

Integrated mapping analysis of the Werner syndrome region of chromosome 8.

The Werner syndrome locus (WRN) is located at 8p11-p12. To facilitate eventual cloning of the WRN gene, a 10,000-rad radiation-reduced hybrid (RH) cell panel was generated to map genetic markers, sequence-tagged sites (STSs), and genes in this region. A hamster cell line carrying an intact human chromosome 8 was fused with another hamster cell line. Two sets of hybrid cell panels from 2 separate fusions were generated; each panel consisted of 50 independent clones; 33 and 34 cell lines from the 2 fusions retained human chromsome material as determined by inter-Alu PCR. The combined panel was genotyped for 52 markers spanning the entire chromosome, including 10 genes, 29 anonymous polymorphic loci, and 13 STSs. Seventeen of these markers have not been previously described. Markers near the centromere were retained at a higher frequency than more distal markers. Fluorescence in situ hybridization was also used to localize and order a subset of the markers. A RH map of the WRN region was constructed using a maximum likelihood method, giving the following most likely order: D8S131-D8S339 (GSR)-D8S124-D8S278-D8S259-(D8S71)-D8S283- D8S87-D8S105-D8S135 (FGFR1)-D8S135PB-D8S255-ANK1. A genetic map of 15 short tandem repeat polymorphic loci in the WRN region was also constructed. The marker orders from the genetic and RH maps were consistent. In addition, an integrated map of 24 loci in the WRN region was generated using information from both genetic and RH mapping methods. A 1000:1 framework map for 6 loci (LPL-D8S136-D8S137-D8S87-FGFR1-ANK1) was determined by genetic mapping, and the resulting locus order was fixed during analysis of the RH genotype data. The resulting integrated map contained more markers than could confidently be ordered by either genetic or RH mapping alone.

Base Sequence↗
PubMed1994

Structural characterization and chromosomal location of the gene encoding human platelet glycoprotein Ib beta.

Human platelet glycoprotein Ib beta (GPIb beta) (M(r) 22,000) is part of the GPIb-V-IX system that constitutes the receptor for von Willebrand factor and mediates platelet adhesion in the arterial circulation. The four members of the receptor (GPs Ib alpha, Ib beta, V, and IX) share structural and functional features. Individually, GPIb beta contributes to surface expression of the receptor and participates in transmembrane signaling through phosphorylation of its intracellular domain. To define the structure of the GPIb beta gene, a cosmid clone from a human genomic library was analyzed. The transcriptional start site was located by both primer extension and the "anchored" polymerase chain reaction. Similar to the genes for Ib alpha, V, and IX, the Ib beta gene is compact with a single 274-base intron inserted into the 5' end of the open reading frame. The 5'-flanking region of the gene contains both GATA and ets sites that are also found in the 5' promoter regions of other described megakaryocyte/platelet genes. The GPIb beta gene was localized to chromosome 22q11.2 by fluorescence in situ hybridization. The GPIb beta gene has a simple structure, similar to that of other described megakaryocyte/platelet genes, including those of the GPIb-V-IX system.

Amino Acid Sequence↗