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S W Scherer

Publications and source records attributed to S W Scherer.

142 records · Page 8Linked to original sources
PubMed1994

Regional localization of 725 human chromosome 7-specific yeast artificial chromosome clones.

Toward the construction of a complete physical map of human chromosome 7, we have localized 725 YAC clones to cytogenetically defined regions using fluorescence in situ hybridization (FISH) and by screening with DNA markers of known chromosomal locations. These chromosome 7-specific YAC clones are part of a library constructed with DNA isolated from monochromosomal 7 human-hamster somatic cell hybrid lines. The FISH mapping for 575 clones was accomplished by using "Alu-PCR" amplified YAC DNA against metaphase chromosome spreads made from a monochromosomal 7 human-mouse somatic cell hybrid line. Hybridization- or PCR-based screening of previously mapped DNA markers was performed for the mapping of 221 YAC clones. There was excellent correlation between the map locations obtained for the 71 YACs localized with both methods. All of the regionally localized YAC clones are valuable reagents for mapping and identification of disease genes on human chromosome 7.

Animals↗
PubMed1994

Localization of the gene encoding the alpha 2/delta-subunits of the L-type voltage-dependent calcium channel to chromosome 7q and analysis of the segregation of flanking markers in malignant hyperthermia susceptible families.

Malignant hyperthermia susceptibility (MHS) is an autosomal dominant disorder of skeletal muscle which manifests as a potentially fatal hypermetabolic crisis triggered by commonly used anaesthetic agents. The demonstration of genetic heterogeneity in MHS prompted the investigation of the roles played by calcium regulatory proteins other than the ryanodine receptor (RYR1), which is known to be linked to MHS in fewer than half of the European MHS families studied to date. Previously, we have excluded the genes encoding the skeletal muscle L-type voltage-dependent calcium channel alpha 1-, beta 1- and gamma-subunits as candidates for MHS. In this report, we describe the cloning and partial DNA sequence analysis of the gene encoding the alpha 2/delta-subunits, CACNL2A, and its localization on the proximal long arm of chromosome 7q. A new dinucleotide repeat marker close to CACNL2A was identified at the D7S849 locus and tested for linkage in six MHS families. D7S849 and flanking genetic markers were found to co-segregate with the MHS locus through 11 meioses in one, three-generation family. These results suggest that mutations in or near CACNL2A may be involved in some forms of this heterogeneous disorder.

Animals↗
PubMed1994

Physical mapping of the split hand/split foot locus on chromosome 7 and implication in syndromic ectrodactyly.

Split hand/split foot (ectrodactyly; SHSF) is a human developmental malformation characterized by missing digits and claw-like extremities. An autosomal dominant form of this disorder has been mapped to 7q21.3-q22.1; the locus has been designated SHFD1. We have constructed a physical map consisting of overlapping yeast artificial chromosome clones for the entire region. Somatic cell hybrid and fluorescent in situ hybridization analyses were used to define SHSF-associated chromosomal rearrangements in twelve patients. An SHFD1 critical interval of 1.5 Mb was established by analysis of five patients with deletions. Translocation or inversion breakpoints found in six patients were mapped within 700 kb of each other in the critical region. Of note is that eight of the patients analyzed (67%) are in fact classified as having syndromic ectrodactyly. Thus, these mapping data establish a relationship between simple split hand/split foot and this more complex group of human birth defects. Finally, we have mapped DLX5, a member of the Distal-less homeobox gene family, to the SHFD1 critical interval.

Abnormalities, Multiple↗
PubMed1994

Refined localization of the asparagine synthetase gene (ASNS) to chromosome 7, region q21.3, and characterization of the somatic cell hybrid line 4AF/106/KO15.

We have mapped the asparagine synthetase gene (ASNS) to 7q21.3 by fluorescence in situ hybridization. While this study refined the localization of the gene, it also revealed a rearrangement in a somatic cell hybrid line which was used in previous ASNS mapping. Using additional probes from other regions of human chromosome 7, we showed that this cell line (4AF/106/KO15) contained a rearranged chromosome 7 in which a segment of the long arm was apparently duplicated and inserted into the short arm. Caution should be used therefore when interpreting data obtained from this cell line for gene mapping studies.

Animals↗
PubMed1994

Evidence for locus heterogeneity in human autosomal dominant split hand/split foot malformation.

Split hand/split foot (SHSF; also known as ectrodactyly) is a human developmental disorder characterized by missing central digits and other distal limb malformations. An association between SHSF and cytogenetically visible rearrangements of chromosome 7 at bands q21-q22 provides compelling evidence for the location of a causative gene at this location, and the locus has been designated SHFD1. In the present study, marker loci were localized to the SHFD1 critical region through the analysis of somatic cell hybrids derived from individuals with SHSF and cytogenetic abnormalities involving the 7q21-q22 region. Combined genetic and physical data suggest that the order of markers in the SHFD1 critical region is cen-D7S492-D7S527-(D7S479-D7S491)-SHFD1-++ +D7S554-D7S518-qter. Dinucleotide repeat polymorphisms at three of these loci were used to test for linkage of SHSF to this region in a large pedigree that demonstrates autosomal dominant SHSF. Evidence against linkage of the SHSF gene to 7q21-q22 was obtained in this pedigree. Therefore, combined molecular and genetic data provide evidence for locus heterogeneity in autosomal dominant SHSF. We propose the name SHSF2 for this second locus.

Adult↗
PubMed1994

Fine mapping of the autosomal dominant split hand/split foot locus on chromosome 7, band q21.3-q22.1.

Split hand/split foot (SHFD) is a human developmental defect characterized by missing digits, fusion of remaining digits, and a deep median cleft in the hands and feet. Cytogenetic studies of deletions and translocations associated with this disorder have indicated that an autosomal dominant split hand/split foot locus (gene SHFD1) maps to 7q21-q22. To characterize the SHFD1 locus, somatic cell hybrid lines were constructed from cytogenetically abnormal individuals with SHFD. Molecular analysis resulted in the localization of 93 DNA markers to one of 10 intervals surrounding the SHFD1 locus. The translocation breakpoints in four SHFD patients were encompassed by the smallest region of overlap among the SHfD-associated deletions. The order of DNA markers in the SHFD1 critical region has been defined as PON-D7S812-SHFD1-D7S811-ASNS. One DNA marker, D7S811, detected altered restriction enzyme fragments in three patients with translocations when examined by pulsed-field gel electrophoresis (PFGE). These data map SHFD1, a gene that is crucial for human limb differentiation, to a small interval in the q21.3-q22.1 region of human chromosome 7.

Adult↗
PubMed1993

Structure and chromosomal localization of the human constitutive endothelial nitric oxide synthase gene.

Endothelial nitric oxide (NO) synthase is a unique NO synthase isoform that is expressed constitutively by vascular endothelium both in vivo and in vitro and is believed essential to local vascular homeostasis. This calcium/calmodulin-dependent isoform is distinct from neuronal NO synthase. Genomic clones encoding the human endothelial NO synthase were isolated and the structural organization of the gene was determined. The gene contains 26 exons spanning approximately 21 kilobases of genomic DNA, encodes a messenger RNA of 4052 nucleotides, and is present as a single copy in the haploid human genome. Characterization of 5'-flanking genomic regions indicates that the endothelial NO synthase promoter is "TATA-less" and exhibits proximal promoter elements consistent with a constitutively expressed gene that is found in endothelial cells, namely Sp1 and GATA motifs. The 5'-flanking region contains putative AP-1, AP-2, NF-1, heavy metal, acute-phase response shear stress, and sterol-regulatory cis-elements. The human endothelial NO synthase gene was assigned to the 7q35-->7q36 region of chromosome 7 by Southern blot hybridization of human-rodent somatic cell hybrid lines and fluorescence in situ hybridization, whereas human neuronal NO synthase localized to the 12q24.2 region of chromosome 12.

Amino Acid Oxidoreductases↗
PubMed1993

Mapping the midkine family of developmentally regulated signaling molecules.

Midkine (Mdk) and heparin-binding neurotrophic factor (Hbnf)/pleiotrophin (Ptn) comprise the Midkine family of developmentally regulated signaling molecules. We have determined the chromosomal localization of these genes in the mouse by use of single-strand conformation polymorphisms (SSCPs), which facilitated the typing of Mdk and Hbnf alleles in recombinant inbred (RI) strains and interspecific backcrosses. Mapping was performed relative to other cloned genes, as well as simple sequence length polymorphisms (SSLPs) in the interspecific backcrosses. Mdk maps to mouse Chromosome (Chr) 2, linked to the Hoxd gene cluster. Hbnf maps to proximal mouse Chr 6, linked to the Cftr and Cpa genes. Comparative mapping of human MDK and HBNF employing species-specific polymerase chain reaction (PCR) primers and human monochromosomal somatic cell hybrids assigns MDK to human Chr 11 and HBNF to human Chr 7q32-qter.

Animals↗
PubMed1993

Physical mapping of the holoprosencephaly critical region on chromosome 7q36.

Holoprosencephaly (HPE) is a developmental field defect involving the brain and face. Cytogenetic deletions in patients with HPE have localized one of the HPE genes to chromosomal region 7q36. We have characterized the 7q deletions in thirteen HPE patients. The result is the construction of a high resolution physical map of 7q32-qter. As a first step towards cloning an HPE gene crucial for normal brain development, we have defined the HPE minimal critical region in 7q36 between D7S292 and D7S392.

Adult↗
PubMed1993

Refined localization and yeast artificial chromosome (YAC) contig--mapping of genes and DNA segments in the 7q21-q32 region.

The chromosome localizations for 159 gene and DNA segments have been refined to one of five intervals in the 7q21-132 region through hybridization analysis with a panel of somatic cell hybrid lines. Seventy-two of these chromosome 7 markers are also mapped on common or overlapping yeast artificial chromosome (YAC) clones. In addition, the breakpoints of chromosome rearrangement contained in five of the somatic cell hybrid lines have been defined by flanking probes within YAC contigs. To provide a framework for further mapping of the 7q21-q32 region, we have established the physical order of a set of reference markers: cen-(COL1A2-D7S15-CYP3A4-PON)-D7S456-(brea kpoint contained in cell hybrid 1EF2/3/K017)-GUSB-D7S186-ASL-(PGY1-PGY3 -GNB2-EPO-ACHE)-D7S238-(proximal breakpoint in GM1059-Rag5)-D7S240-(CUTL1-PLANH1)-(breakp oints in 1CF2/5/K016 and 2068Rag22-2)-(PRKAR2B-D7S13)-LAMB1-(breakpoint in JSR-17S)-DLD-D7S16-MET-WNT2-CFTR-D7S8-tel.

Base Sequence↗
PubMed1990

Expression and regulation of glucoamylase from the yeast Schwanniomyces castellii.

Expression of the 146-kilodalton (kDa) extracellular glucoamylase by the budding yeast Schwanniomyces castellii is induced by maltose and starch. By use of antiglucoamylase antisera, we found that this expression was regulated at the level of the mRNA, taking place within 30 min after exposure of yeast cells to the respective sugars. Polyacrylamide gel electrophoresis analysis of the in vitro-translated products of total RNA from maltose-treated cells established that the glucoamylase precursor was approximately 120 kDa in size. Stable glucoamylase transcript was not produced in cells exposed to glucose, 2-deoxyglucose, and heat shock. Cells exposed to these two sugars also degraded intracellular and extracellular glucoamylase. In the presence of sugars such as cellobiose, galactose, lactose, and xylose or in the absence of any carbohydrate, a low-level, constitutive-like expression of this preglucoamylase occurred. The nascent glucoamylase underwent at least two posttranslational modifications, resulting in a 138-kDa cell-associated form and the 146-kDa active form that was found free in the medium. These results suggest that glucoamylase expression is tightly regulated similarly to expression of the enzymes responsible for maltose metabolism in Saccharomyces yeasts.

Blotting, Western↗