Search PubMed⌕ Search

SEARCH · Search PubMed

Results for “linkage 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 613 records · Page 34Linked to original sources
PubMed1997

A linkage map of chromosome 6 based on 2 large kindreds segregating bipolar affective disorder.

Twenty-eight markers, both simple sequence repeats (SSRs) and restriction fragment length polymorphisms (RFLPs), were genotyped on members of 2 large pedigrees (OOA, BIP167) segregating bipolar affective disorder. Using the multipoint program "build" of CRIMAP and odds of placement 1000:1, a unique sex-averaged map was generated that spans 227 cM and includes 26 markers. The two other markers were placed on the map with a lower likelihood. The female recombination map is larger than the male recombination map by about 80%. Linkage analysis between the polymorphisms and the disease in the OOA screening pedigree did not result in any significantly positive lod scores nor did a non-parametric, identity-by-descent, method generate any significant p-values. BIP167 was analyzed for allele sharing at the simple sequence repeat loci and significant associations were not found. At present we conclude, that the pedigrees under study do not have a major predisposition gene for bipolar affective disorder on chromosome 6 under the diagnostic and transmission models analyzed by the 2 different methods.

Bipolar Disorder↗
PubMed2003

Integration of a barley (Hordeum vulgare) molecular linkage map with the position of genetic loci hosting 29 developmental mutants.

The first step in positional gene cloning is the integration into available molecular maps of genetic loci for which mutant alleles exist. We report the placement of 29 barley developmental mutants on a restriction fragment length polymorphism-amplified fragment length polymorphism (RFLP-AFLP) map. The mapping procedure used homozygous mutant F(2) plants in an iterative process: once a mutant linked AFLP was found, primer combinations were successively selected to generate AFLP fragments more tightly linked to the mutant locus. The mutants considered were adp, als, aur-a1, aur-a2, br1, br2, bra-d7, cul3, cul5, cul15, cul16, den6, den8, dub1, hex-v3, hex-v4, int-c5, K, li, lig-a2, lk2, lk5, sld1, sld4, tr, trd, unc, uc2 and uz. The 29 mutant loci were linked to the closest molecular markers by distances ranging from 0 to 23 cM, with an average value of 3.8 cM away. Since the efficiency of the mapping procedure is a function of the density of molecular markers, the RFLP-AFLP map of Castiglioni et al was further integrated with new AFLPs using 87 doubled haploid lines derived from the barley cross Igri x Danilo. A total of 819 mapped AFLP marker loci are now available in the combined map.

Chromosome Mapping↗
PubMed2006

A first linkage map of globe artichoke (Cynara cardunculus var. scolymus L.) based on AFLP, S-SAP, M-AFLP and microsatellite markers.

We present the first genetic maps of globe artichoke (Cynara cardunculus var. scolymus L. 2n=2x=34), constructed with a two-way pseudo-testcross strategy. A F1 mapping population of 94 individuals was generated between a late-maturing, non-spiny type and an early-maturing spiny type. The 30 AFLP, 13 M-AFLP and 9 S-SAP primer combinations chosen identified, respectively, 352, 38 and 41 polymorphic markers. Of 32 microsatellite primer pairs tested, 12 identified heterozygous loci in one or other parent, and 7 were fully informative as they segregated in both parents. The female parent map comprised 204 loci, spread over 18 linkage groups and spanned 1330.5 cM with a mean marker density of 6.5 cM. The equivalent figures for the male parent map were 180 loci, 17 linkage groups, 1239.4 and 6.9 cM. About 3% of the AFLP and AFLP-derived markers displayed segregation distortion with a P value below 0.01, and were not used for map construction. All the SSR loci were included in the linkage analysis, although one locus did show some segregation distortion. The presence of 78 markers in common to both maps allowed the alignment of 16 linkage groups. The maps generated provide a firm basis for the mapping of agriculturally relevant traits, which will then open the way for the application of a marker-assisted selection breeding strategy in this species.

Chromosome Mapping↗
PubMed1996

Genetic linkage mapping of the human steroid 5 alpha-reductase type 2 gene (SRD5A2) close to D2S352 on chromosome region 2p23-->p22.

Two steroid 5 alpha-reductase isoenzymes catalyze the conversion of testosterone into dihydrotestosterone, the more bioactive androgen, which is essential for male phenotypic sexual differentiation and for androgen-mediated growth of such tissues and organs as the prostate. Inherited mutations in SRD5A2 cause male pseudohermaphroditism. The SRD5A1 and SRD5A2 genes encoding the steroid 5 alpha-reductase type 1 and type 2 isoenzymes have been previously assigned by in situ hybridization to 5p15 and 2p23, respectively. To map the SRD5A2 gene by linkage analysis, a novel RsaI RFLP detected in exon I and a TA repeat polymorphism found in exon V were genotyped in eight CEPH reference families. A two-point linkage analysis was performed between these polymorphisms and the chromosome 2 microsatellite markers of Généthon and NIH/CEPH. The closest linkage was observed with D2S352 (Zmax = 24.06; thetamax = 0.001) in the region 2p23-->p22. To further define the localization of SRD5A2, a framework map, including nine Généthon markers flanking the polymorphic SRD5A2 locus, was built by multipoint linkage analysis. This led to a high-resolution genetic map of the region flanking the polymorphic SRD5A2 gene, including the nine Généthon markers and three NIH/CEPH markers, yielded the following order: tel-D2S48-D2S149-D2S320-D2S171-D2S165- [D2S352/SRD5A2]-D2S367-[D2S19/D2S177]-[ D2S391/CALM]-D2S378-cen.

Base Sequence↗
PubMed1998

Genetic linkage mapping of the CYP11A1 gene encoding the cholesterol side-chain cleavage P450scc close to the CYP1A1 gene and D15S204 in the chromosome 15q22.33-q23 region.

The first rate-limiting step in the biosynthesis of all mammalian steroid hormones is the conversion of cholesterol to pregnenolone by the cholesterol side-chain cleavage enzyme, P450scc. The human CYP11A1 gene, encoding the mitochondrial P450scc, has been previously assigned by in situ hybridization to 15q23-q24 region. To map the CYP11A1 gene with linkage analysis, a novel TAAAA repeat polymorphism, found in its promoter region, was genotyped in the eight largest CEPH reference families, which included 91 children, 16 parents and 26 grandparents. Two-point linkage analysis was performed between this tetra-allelic polymorphism and the chromosome 15 microsatellite markers of Généthon as well as the tetranucleotide polymorphism of the CYP19 gene and a MspI RFLP of the CYP1A1 gene. A close linkage was observed with D15S204 (Z max = 27.33; theta max = 0.009) and CYP1A1 gene (Z max = 6.62; theta max = 0.001), but not with the CYP19 gene (Z max = 4.06; theta max = 0.26). The CYP19 gene that encodes the P450arom was rather closely linked with D15S123 (Z max = 31.04; theta max = 0.001). A framework map, including Généthon markers flanking the polymorphic CYP11A1 and CYP19 genes, was built by multipoint linkage analysis. Thereafter, a high-resolution genetic map of the 15q15-q25.3 region was constructed, yielding to the following order: cen-D15S214-[D15S123; CYP19]-D15S117-D15S159-D15S153-D15S983-[++ +D15S204; CYP11A1; CYP1A1]-D15S211-D15S152-D15S199-tel. Thus, the CYP11A1 gene is closely linked with the CYP1A1 gene, whereas it is located approximately 27.4 cM telomeric to the CYP19 gene.

Alleles↗
PubMed1999

Five new linkage groups in the canine linkage map.

Nineteen further polymorphic loci were typed on the DogMap reference panel. Five new linkage groups were identified. Additionally, five markers were added to earlier defined linkage groups. Three of the new linkage groups contain markers mapped earlier to specific dog chromosomes by physical mapping. These results make a further contribution to the canine genome map and provides more linkage groups physically assigned to known chromosomes.

Animals↗
PubMedDate not supplied

Linkage mapping in populations with karyotypic rearrangements.

A simulation study was used to examine the consequences of karyotypic rearrangements on molecular genetic map construction. Two groups of 50 datasets were created for F2 populations segregating for a reciprocal translocation of chromosomal segments or a reciprocal translocation and inversion. Multiple attempts were made to construct maps for each dataset using MapMaker/EXP. As expected, the markers from segments involved in the translocation formed one linkage group. Maps that corresponded to the known marker order within a segment could be constructed by the following method. The separation of markers distal to the translocation breakpoints into their respective segments could be made by constructing multiple maps, using distinct orders of marker entry, and observing the variances in intermarker distances: variances between pairs of markers from the same segment were an order of magnitude less compared to pairs where markers were from different segments. The order of markers within a segment could be determined from combining the pairwise linkage results from multiple maps, or from maps including all markers from a segment. No bias in map distances was observed. These results indicate that, under conditions similar to those tested, genetic maps corresponding to the segments conserved in translocations can be constructed.

Chromosome Inversion↗