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A M Frischauf

Publications and source records attributed to A M Frischauf.

At least 19 recordsLinked to original sources
PubMed1992

Yeast artificial chromosomes for the molecular analysis of the familial polyposis APC gene region.

Two yeast artificial chromosomes (YACs) spanning a total distance of 1.1 megabase pairs of DNA around the MCC (for mutated in colorectal carcinoma) and APC (for adenomatous polyposis coli) genes at 5q21 have been isolated and characterized. Starting from the MCC gene, a strategy was undertaken to identify constitutional submicroscopic deletions in familial adenomatous polyposis patients that might considerably narrow down the position of the APC gene. To this end, YACs identified by the MCC gene were screened across a chromosome 5-specific cosmid library to provide a source of DNA probes for genomic scanning. The cosmids isolated from these experiments were used to screen a panel of somatic cell hybrids containing chromosome 5 segregated from patients suspected to carry putative interstitial deletions. This screening approach led to the confirmation of a small heterozygous deletion in a polyposis patient that overlaps one of the two isolated YACs. This YAC has been shown to contain the entire APC gene, in addition to a significant portion of DNA flanking the 5' end of the gene, and should therefore prove a valuable resource for functional studies by transfer to colorectal tumor-derived cell lines.

Adenomatous Polyposis Coli↗
PubMed1992

Construction of a map of chromosome 16 by using radiation hybrids.

A human-hamster cell hybrid carrying a single copy of chromosome 16 as the only human genetic material was irradiated with a single dose of gamma-rays (7000 rads; 1 rad = 0.01 Gy) and then fused with a thymidine kinase-deficient hamster cell line (RJKM) to generate radiation hybrids retaining unselected fragments of this human chromosome. In two experiments, 223 hybrids were isolated in hypoxanthine/aminopterine/thymidine (HAT) medium and screened with 38 DNA probes, corresponding to anonymous DNA or gene sequences localized on chromosome 16. The most likely order and location of the 38 DNA sequences were established by multiple pairwise analysis and scaled to estimate physical distance in megabases. The order and the distances thus obtained are mostly consistent with available data on genetic and physical mapping of these markers, illustrating the usefulness of radiation hybrids for mapping.

Chromosome Mapping↗
PubMed1992

Radiation hybrid map spanning the Huntington disease gene region of chromosome 4.

Radiation hybrid (RH) mapping was used to construct a map of 11 markers in the distal 4 Mb of the short arm of chromosome 4, the region containing the Huntington disease gene. Two different methods for deriving the order of the markers were compared and both arrived at the same order as being the most likely. This order is also consistent with both the physical map constructed using pulsed-field gel electrophoresis (PFGE) and the meiotic linkage map. Comparing the RH map to the map determined by PFGE provided the means to equate RH map units (centirays) with actual physical distance in kilobases of DNA. In addition, a simple procedure for reducing the complexity of human DNA in radiation hybrids is described. One cell line isolated using this procedure contains, as its only human DNA, approximately 2 Mb surrounding the Huntington disease gene.

Chromosome Mapping↗
PubMed1992

Human-mouse homologies in the region of the polycystic kidney disease gene (PKD1).

Autosomal dominant polycystic kidney disease (PKD1) is linked to the alpha-globin locus near the telomere of chromosome 16p. We established the existence of a conserved linkage group in mouse by mapping conserved sequences and cDNAs from the region surrounding the PKD1 gene in the mouse genome. Results obtained with the BXD recombinant strain system and somatic cell hybrids show the homologous region to be located on mouse chromosome 17 near the globin pseudogene Hba-ps4, an unprocessed alpha-like globin gene. The markers we mapped are widely distributed over the region known to contain the PKD1 gene, and it is therefore likely that the mouse homologue of PKD1 is also located on mouse chromosome 17.

Animals↗
PubMed1992

The gene for autosomal dominant polycystic kidney disease lies in a 750-kb CpG-rich region.

PKD1, the locus most commonly affected by mutations that produce autosomal dominant polycystic kidney disease (ADPKD), has previously been localized to chromosome 16p13.3. Since no cytogenetic abnormalities have been found in association with ADPKD, flanking genetic markers have been required to define an interval--the PKD1 region--that contains the PKD1 gene. In this report we demonstrate, through the construction of a long-range restriction map that links the flanking genetic markers GGG1 (D16S84) and 26.6PROX (D16S125), that the PKD1 gene lies within an extremely CpG-rich 750-kb segment of chromosome 16p13.3. Approximately 90% of this region has been cloned in three extensive cosmid/bacteriophage contigs. The cloned DNA is a valuable resource for identifying new closer flanking genetic markers and for isolating candidate genes from the region.

Chromosomes, Human, Pair 16↗
PubMed1992

Assay by polymerase chain reaction (PCR) of multi-allele polymorphisms in the Huntington's disease region of chromosome 4.

The Huntington's disease-linked D4S115 marker has been converted from a DNA blot assay to a more sensitive and rapid polymerase chain reaction (PCR) assay. PCR amplification of a tandem repeat at D4S115 revealed 7 allelic fragments, ranging in size from approximately 610 to 915 bp, differing in their apparent copy number of a approximately 55 bp core repeat. This repeat unit differs strikingly in sequence from the repeat units of other multi-allele markers from chromosome region 4p 16.3, arguing that the VNTR (Variable Number of Tandem Repeats) loci clustered in this region did not arise from a common ancestral sequence. The D4S115 marker can be assayed simultaneously with PCR products from D4S125, D4S95 and D4S43 on a single agarose gel, providing a rapid scan for successful amplification of these difficult-to-assay VNTRs, and for inheritance of the entire candidate Huntington's disease region. This approach should help to increase the speed, informativeness and accuracy of presymptomatic and prenatal linkage testing in this devastating disorder.

Alleles↗
PubMed1991

Huntington disease-linked locus D4S111 exposed as the alpha-L-iduronidase gene.

alpha-L-Iduronidase (IDUA) has been intensively studied due to its causative role in mucopolysaccharidosis type I (Hurler, Scheie and Hurler/Scheie syndromes). The recent cloning of a human IDUA cDNA has resulted in a reevaluation of the chromosomal location of this gene. Previously assigned to chromosome 22, IDUA now has been localized to 4p16.3, the region of chromosome 4 associated with Huntington's disease (HD). The existence of a battery of cloned DNA, physical map information, and genetic polymorphism data for this region has allowed the rapid fine mapping of IDUA within the terminal cytogenetic band of 4p. IDUA was found to be coincident with D4S111, an anonymous locus displaying a highly informative multiallele DNA polymorphism. This map location, 1.1 X 10(6) bp from the telomere, makes IDUA the most distal cloned gene assigned to 4p. However, it falls within a segment of 4p16.3 that has been eliminated from the HD candidate region, excluding a role for IDUA in this disorder.

Alleles↗
PubMed1991

Construction and regional localization of clones from a NotI linking library from human chromosome 17q.

A NotI linking library was constructed from a somatic cell hybrid containing chromosome 17q as its only human material. A total of 112 human clones were assigned to nine regions of 17q using a somatic cell hybrid mapping panel. The library includes clones that detect the acute promyelocytic leukemia and von Recklinghausen neurofibromatosis translocation breakpoints at 17q11.2-12 and 17q11.2, respectively, on pulsed-field gel electrophoresis. The mapped clones represent over 50% of the estimated number of NotI sites on 17q, and therefore constitute an important resource for long-distance mapping.

Chromosome Mapping↗
PubMed1991

Saturating the region of the polycystic kidney disease gene with NotI linking clones.

A NotI-linking library was constructed from a radiation hybrid containing fragments of human chromosome 16. The clones were mapped on a panel of somatic cell hybrids, and 10 different NotI site-containing clones were localized close to and between genetic markers flanking the PKD1 locus. With pulsed-field gel analysis the clones were shown to be distributed over four adjacent ClaI fragments covering 1,200 kb.

Animals↗
PubMed1990

A gene from the human sex-determining region encodes a protein with homology to a conserved DNA-binding motif.

A search of a 35-kilobase region of the human Y chromosome necessary for male sex determination has resulted in the identification of a new gene. This gene is conserved and Y-specific among a wide range of mammals, and encodes a testis-specific transcript. It shares homology with the mating-type protein, Mc, from the fission yeast Schizosaccharomyces pombe and a conserved DNA-binding motif present in the nuclear high-mobility-group proteins HMG1 and HMG2. This gene has been termed SRY (for sex-determining region Y) and proposed to be a candidate for the elusive testis-determining gene, TDF.

Amino Acid Sequence↗
PubMed1989

The pseudoautosomal boundary in man is defined by an Alu repeat sequence inserted on the Y chromosome.

The Y chromosome, which in man determines the male sex, is composed of two functionally distinct regions. The pseudoautosomal region is shared between the X and Y chromosome and is probably required for the correct segregation of the sex chromosomes during male meiosis. The second region includes the sex-determining gene(s), the presence of which is necessary for the development of testes. The two regions have contrasting genetic properties: the pseudoautosomal region recombines between the X and Y chromosome; the Y-specific region must avoid recombination otherwise the chromosomal basis of sex-determination breaks down. The pseudoautosomal region is bounded at the distal end by the telomere and at the proximal end by X- and Y-specific DNA. We have found that the proximal boundary was formed by the insertion of an Alu sequence on the Y chromosome early in the primate lineage. Proximal to the Alu insertion there is a small region where similarity between the X and Y chromosomes is reduced and which is no longer subject to recombination.

Base Sequence↗
PubMed1989

A new DNA marker (D4S90) is located terminally on the short arm of chromosome 4, close to the Huntington disease gene.

Genetic linkage studies have mapped Huntington's disease (HD) to the distal portion of the short arm of chromosome 4 (4p16.3), 4 cM distal to D4S10 (G8). To date, no definite flanking marker has been identified. A new DNA marker, D4S90 (D5); which maps to the distal region of 4p16.3, is described. The marker was used in a genetic linkage study in the CEPH reference families with seven other markers at 4p16. The study, together with knowledge of the physical map of the region, places D4S90 as the most distal marker, 6 cM from D4S10. A provisional linkage study with HD gave a maximum lod score of 2.14 at a theta of 0.00 and no evidence of linkage disequilibrium. As D4S90 appears to be located terminally, it should play an important role in the accurate mapping and cloning of the HD gene.

Blotting, Southern↗
PubMed1989

CpG island clones from a deletion encompassing the gene for adenomatous polyposis coli.

Adenomatous polyposis coli (APC), a dominantly inherited disorder, has been mapped to chromosome 5q15-q21 by family linkage studies. Cells from patients with deletions in this region, in one case associated with polyposis in a family, have been used to construct human hamster hybrid cell lines that retain either the normal or deleted chromosome 5. These lines have been used to identify markers from the region of the polyposis gene obtained by cloning the ends of 0.5- to 2-megabase BssHII fragments purified by pulsed-field gel electrophoresis. Three markers are described that map within the deletions and must therefore be close to the APC gene.

Adenoma↗
PubMed1989

Genetic analysis of colorectal cancer.

Adenomatous polyposis, mainly of the colon, (APC) is a rare dominantly inherited susceptibility to colon cancer in which individuals develop hundreds of polyps mainly in their large bowel. The APC gene has been localised to chromosome 5q21 by following up a case report of an individual with an interstitial deletion on chromosome 5q who had multiple developmental abnormalities together with adenomatous polyposis. A DNA marker (D5S71) was found to be closely linked to APC in family studies and localised to 5q21 by in situ annealing. Material from further patients with deletions in this region of chromosome 5 has been used, by a combination of somatic cell hybrid and long-range DNA analysis, to identify new DNA markers close to the APC gene. These and other markers now provide the basis for genetic counselling of nearly all families with APC. These studies are being extended, together with other approaches for analysing DNA clones around the APC gene, in the search for the gene itself. Allele loss in tumour as compared to normal tissue from sporadic cases of colorectal carcinomas has clearly implicated the APC gene in at least 25 to 40% of all cases of colorectal carcinomas. Similar studies by Vogelstein and others as well as ourselves have further implicated recessive changes on chromosomes 17 and 18 in the development of colorectal carcinomas. Following the demonstration by Vogelstein of the role of p53 mutations in connection with the chromosome 17 changes, we have now shown, using monoclonal antibodies to the mutant p53 products and by other approaches, that changes in the p53 gene may occur in up to 50% or more of colorectal carcinomas. Frequent mutations of the K-ras dominant oncogene, as well as changes in the expression of human leucocyte antigen (HLA)-A, B, C determinants, are further genetic changes that appear commonly to be involved in the progression of colorectal carcinomas. The latter have important implications for T cell immune response to tumours and its manipulation for treatment and even prevention of colorectal cancer. We may soon be approaching a situation when it will become possible to identify all the genetic steps and their sequence during tumour progression, as well as their functional significance largely through the induction of inappropriate growth and the suppression of differentiation.

Adenomatous Polyposis Coli↗