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 415 records · Page 23Linked to original sources
PubMed2005

Single linkage group per chromosome genetic linkage map for the horse, based on two three-generation, full-sibling, crossbred horse reference families.

A genetic linkage map of the horse consisting of 742 markers, which comprises a single linkage group for each of the autosomes and the X chromosome, is presented. The map has been generated from two three-generation full-sibling reference families, sired by the same stallion, in which there are 61 individuals in the F2 generation. Each linkage group has been assigned to a chromosome and oriented with reference to markers mapped by fluorescence in situ hybridization. The average interval between markers is 3.7 cM and the linkage groups collectively span 2772 cM. The 742 markers comprise 734 microsatellite and 8 gene-based markers. The utility of the microsatellite markers for comparative mapping has been significantly enhanced by comparing their flanking sequences with the human genome sequence; this enabled conserved segments between human and horse to be identified. The new map provides a valuable resource for genetically mapping traits of interest in the horse.

Animals↗
PubMed2005

Genetic linkage maps of the red flour beetle, Tribolium castaneum, based on bacterial artificial chromosomes and expressed sequence tags.

A genetic linkage map was constructed in a backcross family of the red flour beetle, Tribolium castaneum, based largely on sequences from bacterial artificial chromosome (BAC) ends and untranslated regions from random cDNA's. In most cases, dimorphisms were detected using heteroduplex or single-strand conformational polymorphism analysis after specific PCR amplification. The map incorporates a total of 424 markers, including 190 BACs and 165 cDNA's, as well as 69 genes, transposon insertion sites, sequence-tagged sites, microsatellites, and amplified fragment-length polymorphisms. Mapped loci are distributed along 571 cM, spanning all 10 linkage groups at an average marker separation of 1.3 cM. This genetic map provides a framework for positional cloning and a scaffold for integration of the emerging physical map and genome sequence assembly. The map and corresponding sequences can be accessed through BeetleBase (http://www.bioinformatics.ksu.edu/BeetleBase/).

Animals↗
PubMed1989

Linkage maps of human chromosomes.

Finding the chromosomal location of human genes that heretofore have been defined solely by phenotypes, in particular clinical phenotypes that are transmitted in Mendelian fashion in families, is an early and often crucial step in the process of identifying the molecular basis of a disease. Recent progress in construction of chromosomal maps of genetically linked DNA markers has made almost the entire human genome accessible to linkage studies in families that are segregating genetic defects. Construction of linkage maps requires a panel of three-generation families for genotyping, a large number of polymorphic markers, and sophisticated computer programs for analysis of genotypic data. After a locus harboring a deleterious mutation has been identified by linkage to a mapped marker, a high-resolution map of the region can be constructed with new markers derived from cosmid libraries, to narrow the search for the gene in question. For example, this strategy has been pursued in the effort to characterize the gene responsible for familial adenomatous polyposis. When a target region has been narrowed to about 1 centiMorgan, corresponding to roughly a million base pairs in physical distance, other techniques of molecular biology can be brought to bear to isolate and clone the actual gene.

Chromosome Mapping↗
PubMed1990

Genetic linkage map of six polymorphic DNA markers around the gene for familial adenomatous polyposis on chromosome 5.

A genetic linkage map of six polymorphic DNA markers close to the gene (APC) for familial adenomatous polyposis (FAP) on chromosome 5q is reported. One hundred fifty-five typed members of nine FAP kindred provided more than 90 meioses for linkage analysis. A number of crucial recombination events have been identified which are informative at three or more loci, allowing confident ordering of parts of the map. There was no evidence of genetic heterogeneity, with all families showing linkage of at least one chromosome 5 marker to the gene. Recombination data and two-point linkage analysis support a locus order of centromere-pi 227-C11P11-ECB27-L5.62-APC-EF5.44-YN5.48-telomer e, although EF5.44 could lie in the interval L5.62-APC or ECB27-L5.62. No recombinants were identified between APC and either EF5.44 or YN5.48, but published deletion mapping in colorectal carcinomas and linkage analysis in FAP suggest that YN5.48 is 1-3 cM from APC. The present study suggests that YN5.48 and L5.62 delineate a small region of chromosome 5 within which the EF5.44 locus lies very close to the APC gene. These data not only allow use of flanking markers for presymptomatic diagnosis of FAP but also provide a high-density map of the region for isolation of the APC gene itself and for further assessment of the role of chromosome 5 deletions in the biology of sporadic colorectal cancer.

Adenomatous Polyposis Coli↗
PubMed1994

A primary linkage map of the porcine genome reveals a low rate of genetic recombination.

A comprehensive genetic linkage map of the porcine genome has been developed by typing 128 genetic markers in a cross between the European Wild Boar and a domestic breed (Large White). The marker set includes 68 polymerase chain reaction-formatted microsatellites, 60 anchored reference markers informative for comparative mapping and 47 markers which have been physically assigned by in situ hybridization. Novel multipoint assignments are provided for 54 of the markers. The map covers about 1800 cM, and the average spacing between markers is 11 cM. We used the map data to estimate the genome size in pigs, thereby addressing the total recombination distance in a third mammalian species. A sex-average genome length of 1873 +/- 139 cM was obtained by comparing the recombinational and physical distances in defined regions of the genome. This is strikingly different from the length of the human genome (3800-4000 cM) and is more similar to the mouse estimate (1600 cM). The recombination rate in females was significantly higher than in males.

Animals↗
PubMed1988

Twelve loci form a continuous linkage map for human chromosome 18.

We have constructed a primary genetic map of human chromosome 18 consisting of 11 DNA markers and one serological marker (JK). Two of these loci define highly polymorphic VNTR systems. The markers define a continuous genetic linkage map of 97 cM in males and 205 cM in females; female genetic distances in a panel of 59 three-generation families were consistently about twice those observed in males. The high odds in support of the linear order of the markers on this recombination map, and the extent of coverage of chromosome 18, indicate that this map will permit efficient linkage studies of human genetic diseases that may be segregating on chromosome 18 and will provide anchor points for development of high-resolution maps for this chromosome.

Alleles↗
PubMed1989

A molecular genetic linkage map of mouse chromosome 9 with regional localizations for the Gsta, T3g, Ets-1 and Ldlr loci.

A 64-centiMorgan linkage map of mouse chromosome 9 was developed using cloned DNA markers and an interspecific backcross between Mus spretus and the C57BL/6J inbred strain. This map was compared to conventional genetic maps using six markers previously localized in laboratory mouse strains. These markers included thymus cell antigen-1, cytochrome P450-3, dilute, transferrin, cholecystokinin, and the G-protein alpha inhibitory subunit. No evidence was seen for segregation distortion, chromosome rearrangements, or altered genetic distances in the results from interspecific backcross mapping. Regional map locations were determined for four genes that were previously assigned to chromosome 9 using somatic cell hybrids. These genes were glutathione S-transferase Ya subunit (Gsta), the T3 gamma subunit, the low density lipoprotein receptor, and the Ets-1 oncogene. The map locations for these genes establish new regions of synteny between mouse chromosome 9 and human chromosomes 6, 11, and 19. In addition, the close linkage detected between the dilute and Gsta loci suggests that the Gsta locus may be part of the dilute/short ear complex, one of the most extensively studied genetic regions of the mouse.

Animals↗
PubMed1990

Estimation of recombination frequencies and construction of RFLP linkage maps in plants from crosses between heterozygous parents.

The construction of a restriction fragment length polymorphism (RFLP) linkage map is based on the estimation of recombination frequencies between genetic loci and on the determination of the linear order of loci in linkage groups. RFLP loci can be identified as segregations of singular or allelic DNA-restriction fragments. From crosses between heterozygous individuals several allele (fragment) configurations are possible, and this leads to a set of formulas for the evaluation of p, the recombination frequency between two loci. Tables and figures are presented illustrating a general outline of gene mapping using heterozygous populations. The method encompasses as special cases the mapping of loci from segregating populations of pure lines. Formulas for deriving the recombination frequencies and information functions are given for different fragment configurations. Information functions derived for relevant configurations are also compared. A procedure for map construction is presented, as it has been applied to RFLP mapping in an allogamous crop.

Alleles↗
PubMed1997

Linkage mapping in experimental crosses: the robustness of single-gene models.

The robustness of parametric linkage mapping against model misspecification is considered in experimental breeding designs, with a focus on localization of the gene. By examining the expected LOD across the genome, it is shown that single-gene models are quite robust, even for polygenic traits. However, when the marker map is of low resolution, linked polygenes can give rise to an apparent "ghost" gene, mapped to an incorrect interval. The results apply equally well to quantitative traits or qualitative (categorical) traits. The results are derived for backcross populations, with a discussion of extensions to intercross populations and relative-pair mapping in humans.

Crosses, Genetic↗
PubMed1989

Restriction Fragment Length Polymorphism Linkage Map of Arabidopsis thaliana.

We have constructed a restriction fragment length polymorphism (RFLP) linkage map of the nuclear genome of the small flowering plant Arabidopsis thaliana. The map is based on the meiotic segregation of both RFLP and morphological genetic markers from five independent crosses. The morphological markers on each of the five chromosomes were included in the crosses to allow alignment of the RFLP map with the established genetic map. The map contains 94 new randomly distributed molecular markers (nine identified cloned Arabidopsis genes and 85 genomic cosmid clones) that detect polymorphisms between the Landsberg erecta and Columbia races. In addition, 17 markers from an independently constructed RFLP map of the Arabidopsis genome [Chang, C., Bowman, J.L., DeJohn, A.W., Lander, E.S., and Meyerowitz, E.M. (1988). Proc. Natl. Acad. Sci. USA 85, 6856-6860] have been included to permit integration of the two RFLP maps.

Journal Article↗
PubMed1994

Distribution of RAPD markers on a linkage map of barley.

The RAPD technique was found to provide reliable genetic markers in barley. A linkage study of 23 RAPDs, 28 RFLPs, and 29 gene loci was conducted on 72 chromosome-doubled haploid progeny lines from a barley cross. The resulting linkage map covered 680 cM, about half of the barley genome. RAPD markers were distributed throughout the map, but a higher than expected frequency of tightly linked RAPDs was observed. Several cases of skewed segregation ratios were observed, but the RAPD markers segregated in ratios similar to their linked loci, confirming that they were reliably scored. In separate crosses, two amplified RAPD products, generated by different primers, were shown to reside in corresponding chromosomal positions. The RAPD markers seem a realistic alternative to RFLP markers in linkage analysis of barley.

Base Sequence↗
PubMed1992

A 2-cM genetic linkage map of human chromosome 7p that includes 47 loci.

A new high-resolution genetic linkage map for human chromosome 7p has been constructed. The map is composed of 47 loci (54 polymorphic systems), 19 of which are uniquely placed with odds of at least 1000:1. Four genes are represented, including glucokinase (GCK, ATP:D-hexose-6-phosphotransferase, EC 2.7.1.2) which was mapped via a (CA)n dinucleotide repeat polymorphism. The sex-average map measures 94.4 cM and the male and female maps measure 73.2 and 116.1 cM, respectively. We believe that the genetic map extends nearly the full length of the short arm of chromosome 7 since a centromere marker has been incorporated, and the most distal marker, D7S21, has been cytogenetically localized by in situ hybridization to 7p22-pter. The average marker spacing is 2 cM, and the largest interval between uniquely placed markers is 13 cM (sex-average map). Overall, female recombination was observed to be about 1.5 times that of males, and a statistically significant sex-specific recombination frequency was found for a single interval. The map is based on genotypic data gathered from 40 CEPH reference pedigrees and was constructed using the CRI-MAP program package. The map presented here represents a combined and substantially expanded dataset compared to previously published chromosome 7 maps, and it will serve as a "baseline" genetic map that should prove useful for future efforts to develop a 1-cM map and for construction of a contiguous clone-based physical map for this chromosome.

Base Sequence↗
PubMed1993

Integration of the cytogenetic and genetic linkage maps of human chromosome 16 using 50 physical intervals and 50 polymorphic loci.

A comprehensive genetic linkage map constructed from 50 loci represented by 68 markers was anchored to 50 cytogenetically defined intervals on human chromosome 16. The linear order of the loci on the cytogenetic map was compatible with the independently derived linear order on the genetic map. The sex-averaged genetic length is 164.5 cM, with an average distance between loci of 3.3 cM. Sex-specific distances are 132.8 cM in males and 201.8 cM in females. This is the first detailed synthesis of genetic and cytogenetic maps for any human chromosome and is the first step in correlating the genetic and physical maps of this chromosome. The combined map, containing 15 loci with a minimum heterozygosity of 60% and 6 PCR-formatted microsatellite markers, will be useful for assignment and regional localization of disease genes to this chromosome.

Chromosome Mapping↗
PubMed1995

Linkage mapping of the angiotensin AT2 receptor gene (Agtr2) to the mouse X chromosome.

Angiotensin II is a potent regulator of cardiovascular homeostasis and binds to two different G-protein-coupled receptors. While the type 1 receptor (AT1) mediates the cardiovascular actions of angiotensin II, the function of the recently cloned type 2 receptor (AT2) remains unknown. We have cloned the mouse AT2 receptor gene (Agtr2) and determined its map position by linkage analysis using an interspecific backcross (C57BL/6J x Mus spretus).Agtr2 is located on the proximal mouse X chromosome between DXMit85 and DXMit49, in a region of conserved synteny with a part of the human X chromosome implicated in inherited forms of premature ovarian failure. The mapping of Agtr2 may expand a region of conserved synteny with human Xq26 that includes Hprt.

Animals↗
PubMed1988

Partial linkage map of chromosome 13q in the region of the Wilson disease and retinoblastoma genes.

Genetic linkage maps are useful tools for defining the location of disease genes. Previously published maps of human chromosome 13 have been incomplete and have had ambiguities of order in the vicinity of the Wilson disease (WND) and retinoblastoma (RB1) genes. We have defined a six-locus map of this region using a large reference pedigree from Venezuela. Our map provides landmarks which will aid in the localization of WND, in determining the extent of deletions in retinoblastoma, and in the mapping of other marker loci.

Chromosome Mapping↗
PubMed1992

Linkage map of eight human chromosome 11q markers, including DRD2, spanning 60 cM.

We have constructed a linkage map of eight RFLP markers located on chromosome 11q in the region of the dopamine D2 receptor gene (DRD2) recognized by probe hD2G1. Abnormalities in dopaminergic neurotransmission mediated by this receptor have been implicated in several psychiatric disorders. The map was generated using six large reference families (from 294 to 419 individuals per locus), which are largely independent of the CEPH families, primarily using the LINKMAP and ILINK programs of the LINKAGE package of Lathrop and Lalouel. The most likely order and recombination frequencies are: [sequence: see text] The relative order of D11S84-STMY, DRD2-D11S29, and D11S146-INT2 could not be resolved reliably. There were no significant sex differences in recombination frequency. We introduce here a version of LINKMAP adapted to run under distributed parallel processing (LINDA-LINKMAP). Using pairwise analyses, we have also placed D11S421 proximal to this group.

Chromosome Mapping↗