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H Himmelbauer

Publications and source records attributed to H Himmelbauer.

32 records · Page 2Linked to original sources

Complex probes for high-throughput parallel genetic mapping of genomic mouse BAC clones.

We describe a novel approach for the identification and mapping of polymorphic markers. Amplicons are generated by ligation of double-stranded adaptor molecules to genomic DNA cleaved with a restriction enzyme. Using primers that extend beyond the restriction site, reduced-complexity subsets of fragments are generated by PCR. Differences in the composition of complex probes generated from DNA of different strains are revealed through hybridization against high-density filter grids of large-insert genomic clones. Genetic mapping of genomic clones is achieved by hybridizing complex probes derived from backcross animals against the polymorphic clones. The mouse was chosen as a model system to test the feasibility of this technique because of the general availability of backcross resources and genomic libraries. Nevertheless, we would expect the method to be of particular use to generate markers for species that have not yet been extensively studied, because a substantial number of easy-to-use markers can be recruited in a relatively short period of time.

Animals↗

Refined radiation hybrid map of mouse chromosome 17.

We have made a radiation hybrid map of mouse Chromosome (Chr) 17 with 75 microsatellite markers, including those from McCarthy et al. (Genome Res 7, 1153-1161, 1997). Seventy-four of the markers are linked at LOD > 9, and all link at LOD > 5. A LOD 3 framework of 18 markers was used to construct a placement map. The order obtained is in good agreement with genetic maps, and distance estimates give an idea of how recombination rates vary across the chromosome. Recombination is remarkably low with respect to RH break frequency in the region from the centromere to the end of H2. This is similar in interspecific and intersubspecific crosses despite the inversion of a substantial part of this region in Mus spretus with respect to Mus musculus.

Animals↗

High-resolution comparative mapping of mouse chromosome 17.

We have constructed a high-resolution genetic linkage map spanning the proximal 32 cM of mouse chromosome 17 including the t complex. Simple sequence repeats at D17Tu1 and D17Mit6 were employed to identify 121 recombinants among 374 offspring of a (C57BL/6 x CAST/Ei) x C57BL/6 backcross. In contrast to previously reported interspecific Mus domesticus x Mus spretus backcrosses, we did not observe inversion polymorphisms with our cross. This and the relatively high frequency of DNA polymorphisms between C57BL/6 and CAST/Ei allowed us to put 32 RFLV markers and 32 PCR markers on a single map. We present the localization of four new DNA markers and determined map positions for 10 other loci, which previously had been assigned to intervals of the t complex only through the study of partial t haplotype chromosomes.

Animals↗

Rubinstein-Taybi syndrome caused by submicroscopic deletions within 16p13.3.

The Rubinstein-Taybi syndrome (RTS) is a well-defined complex of congenital malformations characterized by facial abnormalities, broad thumbs and big toes, and mental retardation. The breakpoint of two distinct reciprocal translocations occurring in patients with a clinical diagnosis of RTS was located to the same interval on chromosome 16, between the cosmids N2 and RT1, in band 16p13.3. By using two-color fluorescence in situ hybridization, the signal from RT1 was found to be missing from one chromosome 16 in 6 of 24 patients with RTS. The parents of five of these patients did not show a deletion of RT1, indicating a de novo rearrangement. RTS is caused by submicroscopic interstitial deletions within 16p13.3 in approximately 25% of the patients. The detection of microdeletions will allow the objective conformation of the clinical diagnosis in new patients and provides an excellent tool for the isolation of the gene causally related to the syndrome.

Chromosome Deletion↗

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↗

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↗

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↗

Fine genetic localization of the gene for autosomal dominant polycystic kidney disease (PKD1) with respect to physically mapped markers.

PKD1, the gene for the chromosome 16-linked form of autosomal dominant polycystic kidney disease, has previously been genetically mapped to an interval bounded by the polymorphic loci Fr3-42/EKMDA2 distally and O327hb/O90a proximally. More recently, 26.6PROX was identified as the closest proximal flanking locus. We set out to refine the localization of PKD1 by identifying a series of single recombinant events between the flanking markers Fr3-42/EKMDA2 and O327hb/O90a and analyzing them with a new set of polymorphic loci that have been physically mapped within the PKD1 interval. We identified 11 such crossovers in eight families; 6 of these fell into the interval between GGG1 and 26.6PROX, a distance of less than 750 kb. Three of these crossovers placed PKD1 proximal to GGG1 and two crossovers placed PKD1 distal to 26.6PROX. Both of the latter also placed PKD1 telomeric to a locus 92.6SH1.0, which lies 200-250 kb distal to 26.6PROX. The sixth recombinant, however, placed the disease mutation proximal to the locus 92.6SH1.0. Several possible explanations for these observations are discussed. An intensive study to locate deletions, insertions, and other chromosomal rearrangements associated with PKD1 mutations failed to detect any such abnormalities. Thus we have defined, in genetic and physical terms, the segment of 16p13.3 where PKD1 resides and conclude that a gene-by-gene analysis of the region will be necessary to identify the mutation(s).

Chromosome Mapping↗

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↗

Technology development at the interface of proteome research and genomics: mapping nonpolymorphic proteins on the physical map of mouse chromosomes.

Data obtained from protein spots by peptide mass fingerprinting are used to identify the corresponding genes in sequence databases. The relevant cDNAs are obtained as clones from the Integrated Molecular Analysis of Genome Expression (I.M.A.G.E.) consortium. Mapping of I.M.A.G.E. clones is performed in two steps: first, cDNA clones are hybridized against a 10-hit genomic mouse bacterial artificial chromosome (BAC) library. Second, interspersed repetitive sequence polymerase chain reaction (IRS-PCR) using a single primer directed against the mouse B1 repeat element is performed on BACs. As each cDNA detects several BACs, and each individual BAC has a 50% chance to recover an IRS-PCR fragment, the majority of cDNAs produce at least a single IRS-PCR fragment. Individual IRS fragments are hybridized against high-density spotted filter grids containing the three-dimensional permutated pools of yeast artificial chromosome (YAC) library resources that are currently being used to construct a physical map of the mouse genome. IRS fragments that hybridize to YAC clones already placed into contigs immediately provide highly precise map positions. This technology therefore is able to draw links between proteins detected by 2-D gel electrophoresis and the corresponding gene loci in the mouse genome.

Animals↗