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1.
Construction of a BAC contig containing the xa5 locus in rice 总被引:9,自引:0,他引:9
D. Yang A. Sanchez G. S. Khush Y. Zhu N. Huang 《TAG. Theoretical and applied genetics. Theoretische und angewandte Genetik》1998,97(7):1120-1124
The recessive gene xa5 confers resistance to bacterial blight in rice. To generate a physical map of the xa5 locus, three RFLP markers RG556, RG207 and RZ390, closely linked to xa5, were used to screen a rice bacterial artificial chromosome (BAC) library. The identified overlapping BAC clones formed two
small contigs which were extended to both sides by chromosome walking. The final physical map consisted of 14 BAC clones and
covered 550 kb. Genetic analysis with an F2 population showed that two RFLP markers 28N22R and 40F20R, derived from the BAC clones in the contig, flanked the xa5 locus. To further delimit the location of the xa5 locus, RFLP markers RG556 and RG207 were converted to sequence tagged sites and used to perform genetic analysis. The results
indicated that the xa5 locus was most likely located between RG207 and RG556. Among the BAC clones in the contig, one clone, 44B4, hybridized to
both RG207 and RG556. This suggests that BAC clone 44B4 carried the xa5 locus.
Received: 12 January 1998 / Accepted: 27 May 1998 相似文献
2.
In pepper, the TMV resistance locus L is syntenic to the tomato I2 and the potato R3 loci on chromosome 11. In this report, we identified pepper bacterial artificial chromosome (BAC) clones corresponding to
the I2 and R3 loci and developed L-linked markers using the BAC sequence information. A BAC library was screened using the tomato I2C-1 gene as a probe. The resulting clones were sorted further by PCR screening, sequencing, and genetic mapping. A linkage analysis
revealed that BAC clone 082F03 could be anchored to the target region near TG36 on chromosome 11. Using the 082F03 sequence,
more BAC clones were identified and a BAC contig spanning 224 kb was constructed. Gene prediction analysis showed that there
were at least three I2/R3 R gene analogs (RGAs) in the BAC contig. Three DNA markers closely linked (about 1.2 cM) to the L
4
gene were developed by using the BAC contig sequence. The single nucleotide polymorphism marker 087H3T7 developed in this
study was subjected to linkage analysis in L
4
- and L
3
-segregating populations together with previously developed markers. The 189D23M marker, which is known to co-segregate with
L
3
, was located on the opposite side of 087H3T7, about 0.7 cM away from L
4
. This supports the idea that L
3
and L
4
may be different genes closely linked within the region instead of different alleles at the same locus. Finally, use of flanking
markers in molecular breeding program for introgression of L
4
to elite germplasm against most aggressive tobamoviruses pathotype P1,2,3 is discussed. 相似文献
3.
Identification of an 85-kb DNA fragment containing pms1, a locus for photoperiod-sensitive genic male sterility in rice 总被引:7,自引:0,他引:7
N. Liu Y. Shan F. Wang C. Xu K. Peng X. Li Qifa Zhang 《Molecular genetics and genomics : MGG》2001,266(2):271-275
Photoperiod-sensitive genic male-sterile rice has a number of desirable characteristics for hybrid rice production. Previous studies identified pms1, located on chromosome 7, as a major locus for photoperiod-sensitive genic male sterility. The objective of this study was to localize the pms1 locus to a specific DNA fragment by genetic and physical mapping. Using 240 highly sterile individuals and a random sample of 599 individuals from an F2 population of over 5000 individuals from a cross between Minghui 63 and 32001S, we localized the pms1 locus by molecular marker analysis to a genetic interval of about 4 cM, 0.25 cM from RG477 on one side and 3.8 cM from R1807 on the other side. A contig map composed of seven BAC clones spanning approximate 500 kb in length was constructed for the pms1 region by screening a BAC library of Minghui 63 DNA using RFLP markers and chromosomal walking. Analysis of recombination events in the pms1 region among the highly sterile individuals reduced the length of the contig map to three BAC clones. Sequencing of one BAC clone, 2109, identified two SSR markers located 85 kb apart in the clone that flanked the pms1 locus on both sides, as indicated by the distribution of recombination events. We thus concluded that the pms1 locus was located on the fragment bounded by the two SSR markers. 相似文献
4.
Brugmans B Hutten RG Rookmaker AN Visser RG van Eck HJ 《TAG. Theoretical and applied genetics. Theoretische und angewandte Genetik》2006,112(2):269-277
A marker-saturated linkage map of potato was used to genetically map a locus involved in the resistance against wart disease
Synchytrium endobioticum race 1. The locus mapped on the long arm of chromosome 4 and is named Sen1-4 in contrast to a Sen1 locus on chromosome 11. The AFLP markers from the Sen1-4 interval enabled the isolation of BAC clones from an 11 genome equivalent BAC library. This was achieved via fingerprinting
of BAC pools with the AFLP primer pairs that resemble the genetic marker loci. With non-selective AFLP primers, fingerprints
of individual BAC clones were generated to analyse the overlap between BAC clones using FPC. This resulted in a complete contig
and a minimal tiling path of 14 BAC clones enclosing the Sen1-4 locus. The BAC contig has a genetic length of ~6 cM and a physical length of ~1 Mb. Our results demonstrate that map-based
cloning of Sen1-4 can be pursued on the basis of a strategy of marker saturation alone. Genetic resolution achieved by screening large numbers
of offspring for recombination events may not be required. Together with the construction of the BAC contig, a physical map
with the position of the markers is accomplished in one step. This provides proof of concept for the utility of the marker
saturation that is offered by the ultra dense AFLP map of potato for gene cloning. 相似文献
5.
Refined genetic and comparative physical mapping of the canine copper toxicosis locus 总被引:2,自引:0,他引:2
Bart van de Sluis Susan Kole Monique van Wolferen Nigel G. Holmes Peter L. Pearson Jan Rothuizen Bernard A. van Oost Cisca Wijmenga 《Mammalian genome》2000,11(6):455-460
Recently, the copper toxicosis (CT) locus in Bedlington terriers was assigned to canine chromosome region CFA10q26, which is homologous to human chromosome
region HSA2p13-21. A comparative map between CFA10q21-26 and HSA2p13-21 was constructed by using genes already localized to
HSA2p13-21. A high-resolution radiation map of CFA10q21-26 was constructed to facilitate positional cloning of the CT gene. For this map, seven Type I and eleven Type II markers were mapped. Using homozygosity mapping, the CT locus could be confined to a 42.3 cR3000 region, between the FH2523 and C10.602 markers. On the basis of a partial BAC contig, it was estimated that 1-cR3000 is equivalent to approximately 210 kb, implying that the CT candidate region is therefore estimated to be about 9 Mb.
Received: 16 December 1999 / Accepted: 23 February 2000 相似文献
6.
Li L Lu S O'Halloran DM Garvin DF Vrebalov J 《Molecular genetics and genomics : MGG》2003,270(2):132-138
Mutation in the cauliflower gene Or causes high levels of -carotene to accumulate in various tissues of the plant that are normally devoid of carotenoids. To decipher the molecular basis by which Or regulates carotenoid accumulation, we have undertaken the isolation of Or by a map-based cloning strategy. Two previously isolated, locus-specific, sequence-characterized amplified region (SCAR) markers that flank Or were employed for the analysis of a large segregating population consisting of 1632 F2 individuals, and a high-resolution genetic linkage map of the Or locus region was developed. To facilitate positional cloning, we constructed a cauliflower genomic library in a bacterial artificial chromosome (BAC) vector, using high molecular weight DNA from Or homozygotes. The BAC library comprises 60,288 clones with an average insert size of 110 kb, and represents an estimated 10-fold coverage of the genome. A BAC contig encompassing the Or locus was established by screening the library with a marker that is closely linked to Or and by identifying overlapping BAC clones by chromosome walking. Physical mapping delimited the Or locus to a 50-kb DNA fragment within a single BAC clone, which corresponds to a genetic interval of 0.3 cM.Communicated by R. Hagemann 相似文献
7.
Suppressed recombination around the MXC3 locus, a major gene for resistance to poplar leaf rust 总被引:8,自引:0,他引:8
B. Stirling G. Newcombe J. Vrebalov I. Bosdet H.D. Bradshaw Jr. 《TAG. Theoretical and applied genetics. Theoretische und angewandte Genetik》2001,103(8):1129-1137
A positional cloning strategy is being implemented in Populus for the isolation of the dominant MXC3 allele, which confers resistance to poplar leaf rust caused by Melampsora×columbiana (pathotype 3). AFLP markers were used to saturate the chromosomal region around the MXC3 locus in a large (n=1,902) Populus trichocarpa×P. deltoides (T×D) mapping pedigree segregating 1:1 for rust resistance and susceptibility. The high-resolution linkage map developed
around the MXC3 locus contains 19 AFLP markers and spans a genetic distance of 2.73 cM. Of the 19 AFLP markers, seven were found to co-segregate
with the locus. One co-segregating AFLP marker, CCG.GCT_01, was converted to an STS marker (BVS1) and used to identify a physical contig of overlapping BAC clones from the MXC3 region. Genetic and physical mapping of markers isolated from the BAC contig failed to delimit the MXC3 locus within a 300-kb interval defined by the overlapping BAC clones. This result indicates a >25-fold reduction in recombination
frequency in the MXC3 region compared to the average rate of recombination for the Populus genome.
Received: 8 December 2000 / Accepted: 1 March 2001 相似文献
8.
Tom Drader Kara Johnson Robert Brueggeman Dave Kudrna Andris Kleinhofs 《TAG. Theoretical and applied genetics. Theoretische und angewandte Genetik》2009,118(4):811-820
Approaches utilizing microlinearity between related species allow for the identification of syntenous regions and orthologous
genes. Within the barley Chromosome 7H(1) is a region of high recombination flanked by molecular markers cMWG703 and MWG836.
We present the constructed physical contigs linked to molecular markers across this region using bacterial artificial chromosomes
(BAC) from the cultivar Morex. Barley expressed sequence tags (EST), identified by homology to rice chromosome 6 between the
rice molecular markers C425A and S1434, corresponded to the barley syntenous region of Chromosome 7H(1) Bins 2–5 between molecular
markers cMWG703-MWG836. Two hundred and thirteen ESTs were genetically mapped yielding 267 loci of which 101 were within the
target high recombination region while 166 loci mapped elsewhere. The 101 loci were joined by 43 other genetic markers resulting
in a highly saturated genetic map. In order to develop a physical map of the region, ESTs and all other molecular markers
were used to identify Morex BAC clones. Seventy-four BAC contigs were formed containing 2–102 clones each with an average
of 19 and a median of 13 BAC clones per contig. Comparison of the BAC contigs, generated here, with the Barley Physical Mapping
Database contigs, resulted in additional overlaps and a reduction of the contig number to 56. Within cMWG703-MWG836 are 24
agriculturally important traits including the seedling spot blotch resistance locus, Rcs5. Genetic and physical analysis of this region and comparison to rice indicated an inversion distal of the Rcs5 locus. Three BAC clone contigs spanning the Rcs5 locus were identified.
Electronic supplementary material The online version of this article (doi:) contains supplementary material, which is available to authorized users. 相似文献
9.
Fine-mapping of an Arabidopsis cell death mutation locus 总被引:2,自引:0,他引:2
An Arabidopsis cell death mutation locus was mapped to chromosome 2 between lGS1 and mi421. The YAC clone ends, CIC9A3R, CIC11C7L, CIC2G5R and RFLP marker CDs3 within this interval, were used to probe TAMU BAC library and 31 BAC clones were obtained. A BAC contig encompassing the mutation locus, which consists of T6P5, T7M23, T12A21, T8L6 and T18A18, was identified by Southern hybridization with the BAC ends as probes. 11 CAPS and 12 STS markers were developed in this region. These results will facilitate map-based cloning of the genes and sequencing of the genomic DNA in this region. 相似文献
10.
An Arabidopsis cell death mutation locus was mapped to chromosome 2 between /GS1 and mi421. The YAC clone ends, CIC9A3R, CIC11C7L, CIC2G5R and RFLP marker CDs3 within this interval, were used to probe TAMU BAC library and 31 BAC clones were obtained. A BAC contig encompassing the mutation locus, which consists of T6P5, T7M23, T12A21, T8L6 and T18A18, was identified by Southern hybridization with the BAC ends as probes. 11 CAPS and 12 STS markers were developed in this region. These results will facilitate map-based cloning of the genes and sequencing of the genomic DNA in this region. 相似文献