Search PubMed⌕ Search

SEARCH · Search PubMed

Results for “Genetic mapping”

Search indexed PubMed citations on genomics, clinical trials, systematic reviews and public health. Explore titles, authors and supplied subject terms, then open the PubMed record.

Quote a phrase for an exact phrase match. Source license links do not imply unrestricted reuse.

At least 847 records · Page 47Linked to original sources

Genetic mapping of X linked ocular albinism: linkage analysis in British families.

Genetic linkage studies were performed in 16 British families affected by X linked ocular albinism (XLOA) using RFLPs from the Xp22.3 region. Linkage was confirmed between the XLOA locus (OA1) and the loci DXS143 (dic56; Zmax = 15.90 at theta = 0.0, confidence interval (CI) 0-0.035), DXS85 (782; Zmax = 15.67 at theta = 0.04, CI = 0.007-0.11), and DXS237 (GMGX9; Zmax = 12.65 at theta = 0.08, CI = 0.03-0.17). Multipoint linkage analysis placed OA1 between DXS85 (782) and DXS237 (GMGX9) with odds exceeding 10(4):1 to give the map DXS85-(OA1,DXS143)-DXS237-XG-Xpter. OA1 lies close to DXS143 (dic56) but in the absence of recombinants the order of these loci could not be determined.

Albinism, Ocular↗

A comprehensive genetic map of murine chromosome 11 reveals extensive linkage conservation between mouse and human.

Interspecific backcross animals from a cross between C57BL/6J and Mus spretus mice were used to generate a comprehensive linkage map of mouse chromosome 11. The relative map positions of genes previously assigned to mouse chromosome 11 by somatic cell hybrid or genetic backcross analysis were determined (Erbb, Rel, 11-3, Csfgm, Trp53-1, Evi-2, Erba, Erbb-2, Csfg, Myhs, Cola-1, Myla, Hox-2 and Pkca). We also analyzed genes that we suspected would map to chromosome 11 by virtue of their location in human chromosomes and the known linkage homologies that exist between murine chromosome 11 and human chromosomes (Mpo, Ngfr, Pdgfr and Fms). Two of the latter genes, Mpo and Ngfr, mapped to mouse chromosome 11. Both genes also mapped to human chromosome 17, extending the degree of linkage conservation observed between human chromosome 17 and mouse chromosome 11. Pdgfr and Fms, which are closely linked to II-3 and Csfgm in humans on chromosome 5, mapped to mouse chromosome 18 rather than mouse chromosome 11, thereby defining yet another conserved linkage group between human and mouse chromosomes. The mouse chromosome 11 linkage map generated in these studies substantially extends the framework for identifying homologous genes in the mouse that are involved in human disease, for elucidating the genes responsible for several mouse mutations, and for gaining insights into chromosome evolution and genome organization.

Animals↗

Human annexin 31 genetic mapping and origin.

The cDNA encoding novel human annexin 31 was utilized for chromosomal mapping, structural comparison, and phylogenetic analysis to clarify its genetic relationship to other annexins. The ANX31 gene locus was mapped by fluorescence in situ hybridization to human chromosome 1q21, remote from ten other paralogous human annexins on different chromosomes but near the epidermal differentiation gene complex, the S100A gene cluster and a breast-cancer translocation region. Protein homology testing and characterization of incompletely processed expressed sequence tags identified annexin 2 as the closest extant homologue. Maximum likelihood analysis confirmed its most recent common ancestor with vertebrate annexin 2 and validated its classification, in order of discovery, as annexin 31. This subfamily was formed approx. 500-600millionyears ago, subsequent to the gene duplication that produced annexin 1. It has diverged relatively rapidly and extensively, and specifically in the well-conserved, functionally critical type II calcium-binding sites.

Animals↗

Genetic map position of the gluconate-6-phosphate dehydrogenase gene in Salmonella typhimurium.

Gluconate-6-phosphate dehydrogenase (GND) is genetically determined in Salmonella typhimurium by a locus (gnd) mapping between the somatic antigen (rfb) and histidine (his) operons. The enzyme is constitutive. Strains of Salmonella carrying an F' genetic element which contains the gnd(+) gene have GND activity two to three times that of the wild type. This gene dosage effect was used to determine that the GND reaction is not rate-limiting for the metabolism of glucose by the pentose shunt in S. typhimurium.

Chromosome Mapping↗

Physical and genetic mapping of the macular corneal dystrophy locus on chromosome 16q and exclusion of TAT and LCAT as candidate genes.

PURPOSE: Macular corneal dystrophy (MCD) is an inherited autosomal recessive disorder that has been subdivided into three immunophenotypes, MCD types I, IA and II. We previously mapped the MCD type I gene to chromosome 16q22 and suggested that the MCD type II gene was linked to the same region. The purpose of this study was to construct a genomic contig spanning the MCD region and to narrow the MCD critical interval by haplotype analysis. The TAT and LCAT genes were mapped to determine if they might be the MCD gene. METHODS: The MCD contig was constructed by screening YAC, PAC, and BAC libraries with microsatellite, STS and EST markers, employing a systematic "DNA walking" technique. Polymorphic markers mapped and ordered on the contig were used to screen the MCD affected individuals and their family members for haplotype analysis. RESULTS: Twenty-two YAC, 30 PAC, and 17 BAC clones were mapped to form the MCD contig. Markers mapped on the contig include 19 microsatellite, 14 STS, and 15 EST markers. Moreover, 18 novel STS markers were generated. Using the mapped and ordered microsatellite markers, haplotype analysis on 21 individuals with MCD type I or type II and their family members from Iceland narrowed the MCD interval to 3 overlapping PAC clones. In addition, the TAT and LCAT genes were mapped outside the MCD region. CONCLUSIONS: We established a genomic contig for the MCD region and dramatically narrowed the MCD critical interval. Mapping data show that the TAT and LCAT genes are not the cause of MCD.

Contig Mapping↗

An improved physical and genetic map of the genome of alkaliphilic Bacillus sp. C-125.

Among alkaliphilic bacteria reported so far, Bacillus sp. C-125 is the strain most thoroughly characterized physiologically, biochemically, and genetically. A physical map of the chromosome of this strain was constructed to facilitate further genome analysis, and the genome size was revised from 3.7 to 4.25Mb. Complete digestion of the chromosomal DNA with two rare cut restriction endonucleases, AscI and Sse8387I, each yielded 20 fragments ranging in size from 20 to 600 kb. Seventeen linking clones were isolated in each instance to join the adjacent AscI or Sse8387I fragments in the chromosomal map. All AscI linking clones isolated were sequenced and analyzed by comparison with the BSORF database to map the genes in the chromosome of strain C-125. Several ORFs showing significant similarities to those of B. subtilis in the AscI linking clones were positioned on the physical map. The oriC region of the C-125 chromosome was identified by southern blot analysis with a DNA probe containing the gyrB region.

Bacillus↗

Fine genetic map of mouse chromosome 10 around the polycystic kidney disease gene, jcpk, and ankyrin 3.

A chlorambucil (CHL)-induced mutation of the jcpk (juvenile congenital polycystic kidney disease) gene causes a severe early onset polycystic kidney disease. In an intercross involving Mus musculus castaneus, jcpk was precisely mapped 0.2 cM distal to D10Mit115 and 0.8 cM proximal to D10Mit173. In addition, five genes, Cdc2a, Col6a1, Col6a2, Bcr, and Ank3 were mapped in both this jcpk intercross and a (BALB/c x CAST/Ei)F1 x BALB/c backcross. All five genes were eliminated as possible candidates for jcpk based on the mapping data. The jcpk intercross allowed the orientation of the Ank3 gene relative to the centromere to be determined. D10Mit115, D10Mit173, D10Mit199, and D10Mit200 were separated genetically in this cross. The order and genetic distances of all markers and gene loci mapped in the jcpk intercross were consistent with those derived from the BALB/c backcross, indicating that the CHL-induced lesion has not generated any gross chromosomal abnormalities detectable in these studies.

Animals↗

Genetic mapping and analysis of somatostatin expression in Snell dwarf mice.

Mice homozygous for the gene dwarf (dw) have elevated levels of somatostatin (SS) in extra-hypothalamic brain regions. By in situ hybridization, increased levels of SS mRNA were observed in regions shown previously to contain higher levels of the SS peptide. Thus, the rate of transcription and/or the stability of SS mRNA are affected by the dw mutation. Since both dw and the gene encoding SS, Smst, are located on mouse chromosome 16, two backcrosses segregating dw and Smst were used to determine whether dw is an allele of Smst. In one backcross, an inbred strain derived from the subspecies Mus musculus molossinus was used to provide a high degree of DNA sequence polymorphism. The gene order and map distances determined on this backcross were: (centromere) - Prm-1 - 7 - Igl-1 - 3 - Smst - 29 - dw - 15 - Sod-1 - 4 - Ets-2, demonstrating clearly that Smst and dw are distinct genes. Additional evidence against a primary role for SS excess in the pathogenesis of dw/dw mice was obtained by injecting normal newborn mice with a potent SS analog (cyclo II). In contrast to the pattern of cell loss observed in the dwarf anterior pituitary, the pituitaries of injected mice were indistinguishable from normal controls, further suggesting that the Smst locus is not the primary site of dw gene action.

Alleles↗

Cloning, characterization, and genetic mapping of the rat type 2 angiotensin II receptor gene.

The renin-angiotensin system plays an important role in blood pressure homeostasis, but the contribution of the type 2 angiotensin II receptor (AT2R) is still unclear. The reports that the AT2R gene has been mapped to the X chromosome in human and rat and the previous report of a gene, Bp3, on the X chromosome responsible for an increase in blood pressure have suggested that the rat AT2R gene (Agtr2) could be this gene. To elucidate whether Agtr2 is Bp3, Agtr2 was cloned. A simple sequence repeat in the 3'-flanking region of this gene was identified and used as a genetic marker to map Agtr2 to the X chromosome at 18.1 cM distal to the androgen receptor locus. This map position is outside the confidence interval reported for Bp3, demonstrating that Agtr2 cannot be Bp3. However, these data will enhance the research into the AT2R biology as well as the study of the X chromosome.

Alleles↗

Genetic mapping of resistance to Bacillus thuringiensis toxins in diamondback moth using biphasic linkage analysis.

Transgenic plants producing environmentally benign Bacillus thuringiensis (Bt) toxins are deployed increasingly for insect control, but their efficacy will be short-lived if pests adapt quickly. The diamondback moth (Plutella xylostella), a worldwide pest of vegetables, is the first insect to evolve resistance to Bt toxins in open-field populations. A recessive autosomal gene confers resistance to at least four Bt toxins and enables survival without adverse effects on transgenic plants. Allelic variants of this gene confer resistance in strains from Hawaii, Pennsylvania, and the Philippines. Here we exploited the biphasic nature of Lepidopteran genetic linkage to map this gene in diamondback moth with 207 amplified fragment length polymorphisms as DNA markers. We also cloned and sequenced an amplified fragment length polymorphism marker for the chromosome containing the Bt resistance gene. The results provide a powerful tool for facilitating progress in understanding, monitoring, and managing resistance to Bt.

Animals↗

Improved genetic mapping of X linked retinoschisis.

X linked retinoschisis (RS) causes poor vision in affected males owing to radial cystic changes at the macula. Genetic linkage analysis was carried out in 16 British families with X linked retinoschisis using markers from the Xp22 region. Linkage was confirmed between the RS locus and the markers DXS207 (lod score, Zmax = 17.9 at recombination fraction theta = 0.03; confidence interval for theta = 0.007-0.09), DXS1053 (Zmax = 18.0 at theta = 0.01, CI = 0.001-0.06), DXS43 (Zmax = 12.9 at theta = 0.03, CI = 0.004-0.09), DXS1195 (Zmax = 6.4 at theta = 0.00), DXS418 (Zmax = 8.2 at theta = 0.00), DXS999 (Zmax = 21.2 at theta = 0.01, CI = 0.001-0.05), DXS443 (Zmax = 14.2 at theta = 0.03, CI = 0.004-0.09), DXS365 (Zmax = 24.5 at theta = 0.008, CI = 0.001-0.04). Key recombinants placed RS between DXS43 distally and DXS999 proximally. Multipoint linkage analysis gave odds of 344:1 in favour of this location for RS and supported the map Xpter-(DXS207, DXS1053)-DXS43-1 cM-RS-1 cM-DXS999-DXS443-DXS365-DXS1052-Xcen.

Chromosome Mapping↗

A dense genetic map of the silkworm, Bombyx mori, covering all chromosomes based on 1018 molecular markers.

A dense linkage map was constructed for the silkworm, Bombyx mori, containing 1018 genetic markers on all 27 autosomes and the Z chromosome. Most of the markers, covering approximately 2000 cM, were randomly amplified polymorphic DNAs amplified with primer-pairs in combinations of 140 commercially available decanucleotides. In addition, eight known genes and five visible mutations were mapped. Bombyx homologues of engrailed and invected genes were found to be closely linked, as in Drosophila melanogaster. The average interval between markers was approximately 2 cM, equal to approximately 500 kb. The correspondence of seven linkage groups to counterparts of the conventional linkage map was determined. This map is the first linkage map in insects having a large number of chromosomes (n = 28) that covers all chromosomes without any gaps.

Animals↗