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1.
Multicolor FISH mapping of the dioecious model plant,<Emphasis Type="Italic"> Silene latifolia</Emphasis> 总被引:8,自引:0,他引:8
Lengerova M Kejnovsky E Hobza R Macas J Grant SR Vyskot B 《TAG. Theoretical and applied genetics. Theoretische und angewandte Genetik》2004,108(7):1193-1199
Silene latifolia is a key plant model in the study of sex determination and sex chromosome evolution. Current studies have been based on genetic mapping of the sequences linked to sex chromosomes with analysis of their characters and relative positions on the X and Y chromosomes. Until recently, very few DNA sequences have been physically mapped to the sex chromosomes of S. latifolia. We have carried out multicolor fluorescent in situ hybridization (FISH) analysis of S. latifolia chromosomes based on the presence and intensity of FISH signals on individual chromosomes. We have generated new markers by constructing and screening a sample bacterial artificial chromosome (BAC) library for appropriate FISH probes. Five newly isolated BAC clones yielded discrete signals on the chromosomes: two were specific for one autosome pair and three hybridized preferentially to the sex chromosomes. We present the FISH hybridization patterns of these five BAC inserts together with previously described repetitive sequences (X-43.1, 25S rDNA and 5S rDNA) and use them to analyze the S. latifolia karyotype. The autosomes of S. latifolia are difficult to distinguish based on their relative arm lengths. Using one BAC insert and the three repetitive sequences, we have constructed a standard FISH karyotype that can be used to distinguish all autosome pairs. We also analyze the hybridization patterns of these sequences on the sex chromosomes and discuss the utility of the karyotype mapping strategy presented to study sex chromosome evolution and Y chromosome degeneration.Communicated by J.S. Heslop-Harrison 相似文献
2.
We constructed a sugar beet (Beta vulgaris) bacterial artificial chromosome (BAC) library of the monosomic addition line PAT2. This chromosomal mutant carries a single
additional chromosome fragment (minichromosome) derived from the wild beet Beta patellaris. Restriction analysis of the mutant line by pulsed-field gel electrophoresis was used to determine HindIII as a suitable enzyme for partial digestion of genomic DNA to generate large-insert fragments which were cloned into the
vector pCC1. The library consists of 36,096 clones with an average insert size of 120 kb, and 2.2% of the clones contain mitochondrial
or chloroplast DNA. Based on a haploid genome size of 758 Mbp, the library represents 5.7 genome equivalents providing the
probability of 99.67% that any sequence of the PAT2 genome can be found in the library. Hybridization to high-density filters
was used to isolate 89 BACs containing arrays of the centromere-associated satellite repeats pTS5 and pTS4.1. Using the identified
BAC clones in fluorescent in situ hybridization experiments with PAT2 and Beta patellaris chromosome spreads their wild beet origin and centromeric localization was demonstrated. Multi-colour FISH with differently
labelled satellite repeats pTS5 and pTS4.1 was used to investigate the large-scale organization of the centromere of the PAT2
minichromosome in detail. FISH studies showed that the centromeric satellite pTS5 is flanked on both sides by pTS4.1 arrays
and the arms of the minichromosome are terminated by the Arabidopsis-type telomeric sequences. FISH with a BAC, selected from
high-density filters after hybridization with an RFLP marker of the genetic linkage group I, demonstrated that it is feasible
to correlate genetic linkage groups with chromosomes. Therefore, the PAT2 BAC library provides a useful tool for the characterization
of Beta centromeres and a valuable resource for sugar beet genome analysis. 相似文献
3.
Aert R Sági L Volckaert G 《TAG. Theoretical and applied genetics. Theoretische und angewandte Genetik》2004,109(1):129-139
The complete sequence of Musa acuminata bacterial artificial chromosome (BAC) clones is presented and, consequently, the first analysis of the banana genome organization. One clone (MuH9) is 82,723 bp long with an overall G+C content of 38.2%. Twelve putative protein-coding sequences were identified, representing a gene density of one per 6.9 kb, which is slightly less than that previously reported for Arabidopsis but similar to rice. One coding sequence was identified as a partial M. acuminata malate synthase, while the remaining sequences showed a similarity to predicted or hypothetical proteins identified in genome sequence data. A second BAC clone (MuG9) is 73,268 bp long with an overall G+C content of 38.5%. Only seven putative coding regions were discovered, representing a gene density of only one gene per 10.5 kb, which is strikingly lower than that of the first BAC. One coding sequence showed significant homology to the soybean ribonucleotide reductase (large subunit). A transition point between coding regions and repeated sequences was found at approximately 45 kb, separating the coding upstream BAC end from its downstream end that mainly contained transposon-like sequences and regions similar to known repetitive sequences of M. acuminata. This gene organization resembles Gramineae genome sequences, where genes are clustered in gene-rich regions separated by gene-poor DNA containing abundant transposons.Communicated by J.S. Heslop-Harrison 相似文献
4.
Castillo Ruiz RA Herrera C Ghislain M Gebhardt C 《Molecular genetics and genomics : MGG》2005,274(2):168-179
Defence-response (DR) genes are candidates for the genetic functions underlying quantitative resistance to plant pathogens.
The organization of three DR gene families encoding phenylalanine ammonia lyase (PAL), acidic PR-(pathogenesis-related) protein
5, and basic PR-5, or osmotin-like (OSM), proteins was studied in the potato genome. A bacterial artificial chromosome (BAC)
library containing ~50,000 clones was constructed from high-molecular weight genomic DNA of the diploid potato clone PD59,
a hybrid between Solanum tuberosum and S. phureja. BAC clones carrying one or more copies of the DR genes were identified and characterized by Southern hybridization, sequence
analysis and genetic mapping. PAL, acidic PR-5 and OSM (basic PR-5) genes were all organized into gene families of varying complexity. The PAL gene family consisted of at least 16 members, several of which were physically linked. Four acidic PR-5 homologous were localized to a 45-kb segment on potato chromosome XII. One of these, PR-5/319, codes for the acidic thaumatin-like protein C found in intercellular fluids of potato. Nine OSM genes were organized at two loci: eight form a 90-kb cluster on chromosome VIII, and a single gene was found on chromosome
XI. The topology of a phylogenetic tree based on PR-5 and OSM protein sequences from Solanaceae suggests a mode of evolution
for these gene families. The results will form the basis for further studies on the potential role of these defence-related
loci in quantitative resistance to pathogens. 相似文献
5.
Puerma E Acosta MJ Barragán MJ Martínez S Marchal JA Bullejos M Sánchez A 《Genetica》2008,134(3):287-295
The karyotype of individuals of the species Rhinolophus hipposideros from Spain present a chromosome number of 2n = 54 (NFa = 62). The described karyotype for these specimens is very similar to another previously described in individual
from Bulgaria. However, the presence of one additional pair of autosomal acrocentric chromosomes in the Bulgarian karyotype
and the differences in X chromosome morphology indicated that we have described a new karyotype variant in this species. In
addition, we have analyzed several clones of 1.4 and 1 kb of a PstI repeated DNA sequence from the genome of R. hipposideros. The repeated sequence included a region with high identity with the 5S rDNA genes and flanking regions, with no homology
with GenBank sequences. Search for polymerase III regulatory elements demonstrated the presence of type I promoter elements
(A-box, Intermediate Element and C-box) in the 5S rDNA region. In addition, upstream regulatory elements, as a D-box and Sp1
binding sequences, were present in flanking regions. All data indicated that the cloned repeated sequences are the functional
rDNA genes from this species. Finally, FISH demonstrated the presence of rDNA in nine chromosome pairs, which is surprising
as most mammals have only one carrier chromosome pair. 相似文献
6.
Yan HH Mudge J Kim DJ Larsen D Shoemaker RC Cook DR Young ND 《TAG. Theoretical and applied genetics. Theoretische und angewandte Genetik》2003,106(7):1256-1265
A growing body of research indicates that microsynteny is common among dicot genomes. However, most studies focus on just one or a few genomic regions, so the extent of microsynteny across entire genomes remains poorly characterized. To estimate the level of microsynteny between Medicago truncatula (Mt) and Glycine max (soybean), and also among homoeologous segments of soybean, we used a hybridization strategy involving bacterial artificial chromosome (BAC) contigs. A Mt BAC library consisting of 30,720 clones was screened with a total of 187 soybean BAC subclones and restriction fragment length polymorphism (RFLP) probes. These probes came from 50 soybean contig groups, defined as one or more related BAC contigs anchored by the same low-copy probe. In addition, 92 whole soybean BAC clones were hybridized to filters of HindIII-digested Mt BAC DNA to identify additional cases of cross-hybridization after removal of those soybean BACs found to be repetitive in Mt. Microsynteny was inferred when at least two low-copy probes from a single soybean contig hybridized to the same Mt BAC or when a soybean BAC clone hybridized to three or more low-copy fragments from a single Mt BAC. Of the 50 soybean contig groups examined, 54% showed microsynteny to Mt. The degree of conservation among 37 groups of soybean contigs was also investigated. The results indicated substantial conservation among soybean contigs in the same group, with 86.5% of the groups showing at least some level of microsynteny. One contig group was examined in detail by a combination of physical mapping and comparative sequencing of homoeologous segments. A TBLASTX similarity search was performed between 1,085 soybean sequences on the 50 BAC contig groups and the entire Arabidopsis genome. Based on a criterion of sequence homologues <100 kb apart, each with an expected value of < or =1e-07, seven of the 50 soybean contig groups (14%) exhibited microsynteny with Arabidopsis. 相似文献
7.
The introgressed small-chromosome segment of Agropyron elongatum (Host.) Neviski (Thinopyrum ponticum Podp.) in F5 line II-1-3 of somatic hybrid between common wheat (Triticum aestivum L.) and A. elongatum was localized by sequential fluorescence in situ hybridization (FISH), genomic in situ hybridization (GISH) and karyotype data. Karyotype analysis offered basic data of arm ratios and relative lengths of 21 pairs of chromosomes in parent wheat Jinan177 and hybrid II-1–3. Using special high repetitive sequences pSc119.2 and pAs1 for FISH, the entire B- and D-genome chromosomes were detected. The FISH pattern of hybrid II-1-3 was the same as that of parent wheat. GISH using whole genomic DNA from A. elongatum as probe determined the alien chromatin. Sequential GISH and FISH, in combination with some of the karyotype data, localized the small chromosome segments of A. elongatum on the specific sites of wheat chromosomes 2AL, 1BL, 5BS, 1DL, 2DL and 6DS. FISH with probe OPF-031296 from randomly amplified polymorphic DNA (RAPD) detected E-genome chromatin of A. elongatum, which existed in all of the small chromosome segments introgressed. Microsatellite primers characteristic for the chromosome arms above were used to check the localization and reveal the genetic identity. These methods are complementary and provide comprehensive information about the genomic constitution of the hybrid. The relationship between hybrid traits and alien chromatin was discussed. 相似文献
8.
Genetic and physical maps around the sex-determining <Emphasis Type="Italic">M</Emphasis>-locus of the dioecious plant asparagus 总被引:1,自引:0,他引:1
Telgmann-Rauber A Jamsari A Kinney MS Pires JC Jung C 《Molecular genetics and genomics : MGG》2007,278(3):221-234
Asparagus officinalis L. is a dioecious plant. A region called the M-locus located on a pair of homomorphic sex chromosomes controls the sexual dimorphism in asparagus. The aim of this work
was to clone the region determining sex in asparagus from its position in the genome. The structure of the region encompassing
M should be investigated and compared to the sex-determining regions in other dioecious model species. To establish an improved
basis for physical mapping, a high-resolution genetic map was enriched with AFLP markers closely linked to the target locus
by carrying out a bulked segregant analysis. By screening a BAC library with AFLP- and STS-markers followed by chromosome
walking, a physical map with eight contigs could be established. However, the gaps between the contigs could not be closed
due to a plethora of repetitive elements. Surprisingly, two of the contigs on one side of the M-locus did not overlap although they have been established with two markers, which mapped in a distance as low as 0.25 cM
flanking the sex locus. Thus, the clustering of the markers indicates a reduced recombination frequency within the M-region. On the opposite side of the M-locus, a contig was mapped in a distance of 0.38 cM. Four closely linked BAC clones were partially sequenced and 64 putative
ORFs were identified. Interestingly, only 25% of the ORFs showed sequence similarity to known proteins and ESTs. In addition,
an accumulation of repetitive sequences and a low gene density was revealed in the sex-determining region of asparagus. Molecular
cytogenetic and sequence analysis of BACs flanking the M-locus indicate that the BACs contain highly repetitive sequences that localize to centromeric and pericentromeric locations
on all asparagus chromosomes, which hindered the localization of the M-locus to the single pair of sex chromosomes. We speculate that dioecious Silene, papaya and Asparagus species may represent three stages in the evolution of XX, XY sex determination systems. Given that asparagus still rarely
produces hermaphroditic flowers and has homomorphic sex chromosomes, this species may be an ideal system to further investigates
early sex chromosome evolution and the origins of dioecy. 相似文献
9.
In Allium wakegi, which is an allodiploid species between Allium cepa and Allium fistulosum, each genome can be clearly distinguished using genomic in situ hybridization (GISH). Genomic DNA of A. cepa and A. fistulosum is differentiated both qualitatively and quantitatively. We wanted to isolate nucleotide sequences that give genome-specific signals on A. cepa chromosomes in GISH experiments in A. wakegi. We isolated 23 clones that show GISH-like signal patterns in fluorescence in situ hybridization (FISH) and analyzed their distribution in the A. cepa- and A. fistulosum-derived genomes of A. wakegi. There was considerable variation in the abundance and distribution of these cloned sequences on the chromosomes of the two species. The degree of A. cepa specificity varied among the clones. Twenty-two of the clones showed an even distribution over most chromosome arms with some clustering in the pericentromeric regions, but one clone showed very distinct terminal signals on some chromosomes. Whereas these sequences are not specific for A. cepa, changes in bases in nucleotide sequences and in their amount result in genome-specific characteristics in GISH experiments. 相似文献
10.
BAC-FISH in wheat identifies chromosome landmarks consisting of different types of transposable elements 总被引:12,自引:0,他引:12
Fluorescence in situ hybridization (FISH) has been widely used in the physical mapping of genes and chromosome landmarks in plants and animals. Bacterial artificial chromosomes (BACs) contain large inserts making them amenable for FISH mapping. We used BAC-FISH to study genome organization and evolution in hexaploid wheat and its relatives. We selected 56 restriction fragment length polymorphism (RFLP) locus-specific BAC clones from libraries of Aegilops tauschii (the D-genome donor of hexaploid wheat) and A-genome diploid Triticum monococcum. Different types of repetitive sequences were identified using BAC-FISH. Two BAC clones gave FISH patterns similar to the repetitive DNA family pSc119; one BAC clone gave a FISH pattern similar to the repetitive DNA family pAs1. In addition, we identified several novel classes of repetitive sequences: one BAC clone hybridized to the centromeric regions of wheat and other cereal species, except rice; one BAC clone hybridized to all subtelomeric chromosome regions in wheat, rye, barley and oat; one BAC clone contained a localized tandem repeat and hybridized to five D-genome chromosome pairs in wheat; and four BAC clones hybridized only to a proximal region in the long arm of chromosome 4A of hexaploid wheat. These repeats are valuable markers for defined chromosome regions and can also be used for chromosome identification. Sequencing results revealed that all these repeats are transposable elements (TEs), indicating the important role of TEs, especially retrotransposons, in genome evolution of wheat.Communicated by P.B. Moens 相似文献
11.
Karyotype and cytogenetic markers of Oligosarcus hepsetus from two Brazilian locations in the Paraíba do Sul River Basin (Brazil) were investigated using differential staining techniques (C-banding, silver (Ag)- and chromomycin A3 (CMA3)-staining) and fluorescent in situ hybridization (FISH) using 18 S rDNA and 5 S rDNA probes. The diploid chromosome number was invariably 2n = 50 with 3 pairs of metacentric, 5 pairs of submetacentric, 8 pairs of subtelocentric and 9 pairs of acrocentric chromosomes. No heteromorphic sex chromosomes were observed. The nucleolar organizer regions (NORs) were detected in the short arms of the largest acrocentric pair using Ag-, CMA3- stainings and FISH with 18 S rDNA probe, the latter showing also positive labeling in the short arms of a small acrocentric pair, not visualized by the former methods. FISH with 5 S rDNA probe showed positive labeling in the two chromosome pairs. While the CMA3-staining exhibited GC-rich heterochromatin segments in two pairs of chromosomes, including those coincided with Ag-NORs, the DAPI staining did not reveal any signal, indicating the absence of AT-rich heterochromatin. FISH with an As-51 satellite DNA probe derived from the closely related Astyanax scabripinnis did not reveal any positive signal, demonstrating the absence of this class of DNA in the genome of the specimens under study. 相似文献
12.
To contribute to the knowledge of fish genomes, we identified and characterized by means of nucleotide sequencing and physical
chromosome mapping, three classes of repetitive DNAs in the genome of the South American cichlid fish Astronotus ocellatus. The first class corresponds to a satellite DNA family (AoSat) that shares similarity with a centromeric satellite DNA of the pufferfish Tetraodon nigroviridis. The second repetitive DNA class (AoRex3) is related to the retrotransposon Rex3, which is widely distributed among teleost fishes. The last repetitive element (AoLINE) shows a high similarity to the CR1-like LINE element of other teleosts. The three isolated repetitive elements are clustered in the centromeric heterochromatin
of all chromosomes of the complement. The repetitive sequences are not randomly distributed in the genome, suggesting a pattern
of compartmentalization on chromosomes. 相似文献
13.
Fantinatti BE Mazzuchelli J Valente GT Cabral-de-Mello DC Martins C 《Genetica》2011,139(10):1273-1282
B chromosomes are additional chromosomes widely studied in a diversity of eukaryotic groups, including fungi, plants and animals,
but their origin, evolution and possible functions are not clearly understood. To further understand the genomic content and
the evolutionary history of B chromosomes, classical and molecular cytogenetic analyses were conducted in the cichlid fish
Astatotilapia latifasciata, which harbor 1–2 B chromosomes. Through cytogenetic mapping of several probes, including transposable elements, rRNA genes,
a repeated DNA genomic fraction (C
0
t − 1 DNA), whole genome probes (comparative genomic hybridization), and BAC clones from Oreochromis niloticus, we found similarities between the B chromosome and the 1st chromosome pair and chromosomes harboring rRNA genes. Based on
the cytogenetic mapping data, we suggest the B chromosome may have evolved from a small chromosomal fragment followed by the
invasion of the proto-B chromosome by several repeated DNA families. 相似文献
14.
Kazama Y Sugiyama R Matsunaga S Shibata F Uchida W Hizume M Kawano S 《Journal of plant research》2003,116(4):317-326
The major satellite DNAs of the dioecious plant Silene latifolia are represented by the repetitive sequences X43.1, RMY1 and members of the SacI family, which are located at the distal ends of chromosomes. To characterize the satellite DNAs at the distal ends of the chromosomes in S. latifolia (Sl-distal-satDNA), we isolated a bacterial artificial chromosome clone (number 15B12) that contained multiple repeat sequences with KpnI restriction sites, and subcloned a portion of this sequence into a plasmid vector. Sequencing analysis confirmed that recognition or degenerate sites for KpnI were repeated 26 times at intervals of 310–324 bp in the inserted DNA. The phylogenetic tree that was constructed with the 26 KpnI repeat units contained clustered branches that were independent of the SacI family. It is clear that the KpnI repeat belongs to an Sl-distal-satDNA family that is distinct from the SacI family. We designated this family as "KpnI" after the restriction enzyme that does not have a site in the SacI family. Multi-colored fluorescent in situ hybridization was performed with the KpnI family and RMY1 probes under high stringency conditions. The results suggest that chromosome 7 is unique and that it carries the KpnI family at only one end. 相似文献
15.
Vilarinhos AD Piffanelli P Lagoda P Thibivilliers S Sabau X Carreel F D'Hont A 《TAG. Theoretical and applied genetics. Theoretische und angewandte Genetik》2003,106(6):1102-1106
A bacterial artificial chromosome (BAC) library for banana was constructed from leaves of the wild diploid 'Calcutta 4' clone (Musa acuminata subsp. Burmannicoides 2n = 2 x = 22). 'Calcutta 4' is widely used in breeding programs for its resistance to the current major disease of banana and is being used to build a genetic reference map of banana. As banana leaves are particularly rich in polyphenols and polysaccharides a protocol was adapted to isolate intact nuclei and high-molecular-weight (HMW) DNA. A total of 55,152 clones with an average insert size of 100 kb were picked. The frequency of BAC clones carrying inserts derived from chloroplast and mitochondrial DNA was estimated to be 1.5%. The coverage of the library is equivalent to 9.0-times the haploid genome. The BAC library was screened with 13 RFLP probes belonging to the 8 linkage groups of the consensus molecular map of banana. A total of 135 clones were identified giving an average of 10.38 clones for each locus. This BAC library will be a valuable starting tool for many of the goals of the recently emerged International Musa Genomic Consortium. One of our initial objectives will be to develop a banana physical map by BAC-FISH (fluorescent in situ hybridization) viewing the characterization of translocation break points. 相似文献
16.
The karyotype of diploid Aster iinumae is morphologically similar to that of diploid Aster ageratoides var. ageratoides, however, its chromosome size is apparently smaller (S-type chromosomes versus L-type chromosomes, respectively). The hybrid
origin of tetraploid Aster microcephalus var. ovatus (LS-type chromosomes) has previously been suggested by cytogenetics and chloroplast DNA (cp DNA) data. The cp DNA phylogeny
also implies that the S-type chromosome is apomorphic, which means that genome size reduction occurred on the evolutionary
way to A. iinumae. In this study, we have demonstrated that the chromosome size difference does not depend on the intensity of chromosome condensation
but on the DNA content. The simultaneous genomic in situ hybridization (GISH) results show the similarity between S-type chromosomes
of A. iinumae and A. microcephalus var. ovatus, and between L-type chromosomes of A. ageratoides and A. microcephalus var. ovatus, which provide additional evidence for A. microcephalus var. ovatus being a tetraploid amphidiploid produced by hybridization between S-type chromosomes and L-type chromosomes. The distribution
patterns of Ty1-copia-like retrotransposons were similar in L- and S-type chromosomes. The copies of this retrotransposon dispersed uniformly on
all chromosomes, and it is not yet apparent how the Ty1-copia-like retrotransposon affects the size difference between them. 相似文献
17.
The loci of the 5S and 45S rRNA genes were localized on chromosomes in five species of Capsicum, namely, an-nuum, chacoense, frutescens, baccatum, and chinense by FISH. The 5S rDNA was localized to the distal region of one chromosome in all species observed. The number of 45S rDNA
loci varied among species; one in annuum, two in chacoense, frutescens, and chinense, and four in baccatum, with the exceptions that ‘CM334’ of annuum had three loci and ‘tabasco’ of frutescens had one locus. ‘CM334’-derived BAC clones, 384B09 and 365P05, were screened with 5S rDNA as a probe, and BACs 278M03 and
262A23 were screened with 25S rDNA as a probe. Both ends of these BAC clones were sequenced. FISH with these BAC probes on
pachytenes from ‘CM334’ plant showed one 5S rDNA locus and three 45S rDNA loci, consistent with the patterns on the somatic
chromosomes. The 5S rDNA probe was also applied on extended DNA fibers to reveal that its coverage measured as long as 0.439
Mb in the pepper genome. FISH techniques applied on somatic and meiotic chromosomes and fibers have been established for chili
to provide valuable information about the copy number variation of 45S rDNA and the actual physical size of the 5S rDNA in
chili. 相似文献
18.
An analysis of the primary structure of BAC clone 112D20 T. aestivum, that contains D-genome specific Ty3-Gypsy-retrotransposon Lila is presented. PCR analysis of nulli-tetrasomic and deletion lines of T. aestivum allowed to localize this BAC clone in the distal region of the long arm of chromosome 5D. Characteristic feature of BAC clone 112D20 is a high concentration of Ty3-Gypsy-retrotransposons (61.7%), and low content of the genes (1.2%). Only a single open reading frame was revealed homologous to an unknown gene of Ae. tauschii. Specific to the D-genome Ty3-Gypsy-retrotransposon Lila in the BAC clone 112D20 is 14 kb in length and contains unequal in size long terminal repeats. The data of in situ hybridization and PCR analysis of different Triticeae species suggest that this retroelement was amplified within the ancestral species of Ae. tauschii, the donor D-genome. The suggested time of amplification based on estimation of insertion time of Lila 112D20 is 1.7 million years, which corresponds to the formation of the first allopolyploid forms of wheat. Based on comparison with the previously obtained data, it is concluded that the amplification of retroelements specific to each genome of wheat took place during formation of the diploid progenitors of these genomes. 相似文献
19.
The genus of Secale has many agronomically important characters. In order to use the best of this species, markers tracking the rye chromatin
incorporated into wheat must be developed. In this study, one rye genome-specific random amplified polymorphic DNA (RAPD)
marker was isolated from Secale africanum (Ra genome). Two cloned markers, named OPP131165 and OPP13662, were 1165 bp and 662 bp, respectively. Sequence analysis revealed that OPP131165 was highly homologous to a part of a new class of transposon-like gene called the Revolver family, and OPP13662 was partially similar to LTR gypsy-like retrotransposon. Fluorescence in situ hybridization (FISH) showed only OPP131165 localized within the whole arms of rye except their terminal regions and no signal was detected on wheat chromosomes, while
OPP13662 had no hybridization signal detected on wheat and rye genomes. Based on these sequences, two pairs of sequence-characterized
amplified region (SCAR) primers were designed, and the resulted SCAR markers were able to target both cultivated and wild
Secale species. The FISH patterns and the two SCAR markers should be able to identify and track all wheat-rye translocation lines,
especially the S. africanum chromatin. 相似文献
20.
Cenci A Chantret N Kong X Gu Y Anderson OD Fahima T Distelfeld A Dubcovsky J 《TAG. Theoretical and applied genetics. Theoretische und angewandte Genetik》2003,107(5):931-939
Durum wheat (Triticum turgidum ssp. durum, 2n = 4x = 28, genomes AB) is an economically important cereal used as the raw material to make pasta and semolina. In this paper we present the construction and characterization of a bacterial artificial chromosome (BAC) library of tetraploid durum wheat cv. Langdon. This variety was selected because of the availability of substitution lines that facilitate the assignment of BACs to the A and B genome. The selected Langdon line has a 30-cM segment of chromosome 6BS from T. turgidum ssp. dicoccoides carrying a gene for high grain protein content, the target of a positional cloning effort in our laboratory. A total of 516,096 clones were organized in 1,344 384-well plates and blotted on 28 high-density filters. Ninety-eight percent of these clones had wheat DNA inserts (0.3% chloroplast DNA, 1.4% empty clones and 0.3% empty wells). The average insert size of 500 randomly selected BAC clones was 131 kb, resulting in a coverage of 5.1-fold genome equivalents for each of the two genomes, and a 99.4% probability of recovering any gene from each of the two genomes of durum wheat. Six known copy-number probes were used to validate this theoretical coverage and gave an estimated coverage of 5.8-fold genome equivalents. Screening of the library with 11 probes related to grain storage proteins and starch biosynthesis showed that the library contains several clones for each of these genes, confirming the value of the library in characterizing the organization of these important gene families. In addition, characterization of fingerprints from colinear BACs from the A and B genomes showed a large differentiation between the A and B genomes. This library will be a useful tool for evolutionary studies in one of the best characterized polyploid systems and a source of valuable genes for wheat. Clones and high-density filters can be requested at
Communicated by P. LangridgeThe first two authors contributed equally to the investigation 相似文献