共查询到20条相似文献,搜索用时 265 毫秒
1.
Z. Deng Q. Tao Y.-L. Chang S. Huang P. Ling C. Yu C. Chen F. G. Gmitter Jr. H.-B. Zhang 《TAG. Theoretical and applied genetics. Theoretische und angewandte Genetik》2001,102(8):1177-1184
A BAC library was constructed from the genomic DNA of an intergeneric Citrus and Poncirus hybrid. The library consists of 24,576 clones with an average insert size of 115 kb, representing approximately seven haploid
genome equivalents and is able to give a greater than 99% probability of isolating single-copy citrus DNA sequences from this
library. High-density colony hybridization-based library screening was performed using DNA markers linked to the citrus tristeza
virus (CTV) resistance gene and citrus disease resistance gene candidate (RGC) sequences. Between four and eight clones were
isolated with each of the CTV resistance gene-linked markers, which agrees with the library’s predicted genome coverage. Three
hundred and twenty-two clones were identified using 13 previously cloned citrus RGC sequences as probes in library screening.
One to four fragments in each BAC were shown to hybridize with RGC sequences. One hundred and nine of the RGC BAC clones were
fingerprinted using a sequencing gel-based procedure. From the fingerprints, 25 contigs were assembled, each having a size
of 120–250 kb and consisting of 2–11 clones. These results indicate that the library is a useful resource for BAC contig construction
and molecular isolation of disease resistance genes.
Received: 22 May 2000 / Accepted: 25 September 2000 相似文献
2.
Construction of a bacterial artificial chromosome library of Medicago truncatula and identification of clones containing ethylene-response genes 总被引:6,自引:0,他引:6
Y.-W. Nam R. V. Penmetsa G. Endre P. Uribe D. Kim D. R. Cook 《TAG. Theoretical and applied genetics. Theoretische und angewandte Genetik》1999,98(3-4):638-646
To facilitate genome analysis and map-based cloning of symbiotic genes in the model legume Medicago truncatula, a bacterial artificial chromosome (BAC) library was constructed. The library consists of 30 720 clones with an average insert
size of approximately 100 kb, representing approximately five haploid-genome equivalents. The frequency of BAC clones carrying
inserts of chloroplast DNA was estimated to be 1.4%. Screening of the library with single- or low-copy genes as hybridization
probes resulted in the detection of 1–12 clones per gene. Hybridization of the library with repeated sequences such as rDNA
genes and transposon-like elements of M. truncatula revealed the presence of 60 and 374 BAC clones containing the two sequences, respectively. The BAC library was pooled for
screening by polymerase chain reaction (PCR)-amplification. To demonstrate the utility of this system, we used primers designed
from a conserved region of the ein3-like loci of Arabidopsis thaliana and isolated six unique BAC clones from the library. DNA gel-blot and sequence analyses showed that these ein3-like clones could be grouped into three classes, an observation consistent with the presence of multiple ein3-like loci in M. truncatula. These results indicate that the BAC library represents a central resource for the map-based cloning and physical mapping
in M. truncatula and other legumes.
Received: 27 July 1998 / Accepted: 5 August 1998 相似文献
3.
Sangdun Choi Robert A. Creelman John E. Mullet Rod A. Wing 《Plant Molecular Biology Reporter》1995,13(2):124-128
We constructed an ordered 3,948-clone arabidopsis BAC library. The library has a combined average insert size of 100 kb (n=54).
Assuming a haploid genome size of 100,000 kb, the BAC library contains 3.95 haploid genome equivalents with a 98 percent probability
of isolating a specific genomic region. The library was screened with five arabidopsis cDNA probes and one tomato probe; all
probes hybridized to at least one (and in most cases three) BAC clones in the library. 相似文献
4.
Heng Zhu Sangdun Choi Andrea K. Johnston Rod A. Wing Ralph A. Dean 《Fungal genetics and biology : FG & B》1997,21(3):337-347
Magnaporthe grisea(Hebert) Barr causes rice blast, one of the most devastating diseases of rice (Oryza sativa) worldwide. This fungus is an ideal organism for studying a number of aspects of plant–pathogen interactions, including infection-related morphogenesis, avirulence, and pathogen evolution. To facilitateM. griseagenome analysis, physical mapping, and positional cloning, we have constructed a bacterial artificial chromosome (BAC) library from the rice infecting strain 70-15. A new method was developed for separation of partially digested large-molecular-weight DNA fragments that facilitated library construction with large inserts. The library contains 9216 clones, with an average insert size of 130 kbp (>25 genome equivalents) stored in 384-well microtiter plates that can be double spotted robotically on to a single nylon membrane. Several unlinked single-copy DNA probes were used to screen 4608 clones in the library and an average of 13 (minimum of 6) overlapping BAC clones was found in each case. Hybridization of total genomic DNA to the library and analysis of individual clones indicated that ≈26% of the clones contain single-copy DNA. Approximately 35% of BAC clones contained the retrotransposon MAGGY. The library was used to identify BAC clones containing a adenylate cyclase gene (mac1). In addition, a 550-kbp contig composed of 6 BAC clones was constructed that encompassed two adjacent RFLP markers on chromosome 2. These data show that the BAC library is suitable for genome analysis ofM. grisea.Copies of colony hybridization membranes are available upon request. 相似文献
5.
A. C. J. Frijters Z. Zhang M. van Damme G.-L. Wang P. C. Ronald R. W. Michelmore 《TAG. Theoretical and applied genetics. Theoretische und angewandte Genetik》1997,94(3-4):390-399
Existing bacterial artificial chromosome (BAC) vectors were modified to have unique EcoRI cloning sites. This provided an additional site for generating representative libraries from genomic DNA digested with
a variety of enzymes. A BAC library of lettuce was constructed following the partial digestion of genomic DNA with HindIII or EcoRI. Several experimental parameters were investigated and optimized. The BAC library of over 50,000 clones, representing one
to two genome equivalents, was constructed from six ligations; average insert sizes for each ligation varied between 92.5
and 142 kb with a combined average insert size of 111 kb. The library was screened with markers linked to disease resistance
genes; this identified 134 BAC clones from four regions containing resistance genes. Hybridization with low-copy genomic sequences
linked to resistance genes detected fewer clones than expected from previous estimates of genome size. The lack of hybridization
to chloroplast and mitochondrial sequences demonstrated that the library was predominantly composed of nuclear DNA. The unique
EcoRI site in the BAC vector should allow the integration of BAC cloning with other technologies that utilize EcoRI digestion, such as AFLPTM markers and RecA-assisted restriction endonuclease (RARE) cleavage, to clone specific large EcoRI fragments from genomic DNA.
Received: 5 August 1996 / Accepted: 23 August 1996 相似文献
6.
Songhun Jang Hang Liu Jianguo Su Feng Dong Feng Xiong Lanjie Liao Yaping Wang Zuoyan Zhu 《Marine biotechnology (New York, N.Y.)》2010,12(3):261-266
Bacterial artificial chromosome (BAC) library is an important tool in genomic research. We constructed two libraries from
the genomic DNA of grass carp (Ctenopharyngodon idellus) as a crucial part of the grass carp genome project. The libraries were constructed in the EcoRI and HindIII sites of the vector CopyControl pCC1BAC. The EcoRI library comprised 53,000 positive clones, and approximately 99.94% of the clones contained grass carp nuclear DNA inserts
(average size, 139.7 kb) covering 7.4× haploid genome equivalents and 2% empty clones. Similarly, the HindIII library comprised 52,216 clones with approximately 99.82% probability of finding any genomic fragments containing single-copy
genes; the average insert size was 121.5 kb with 2.8% insert-empty clones, thus providing genome coverage of 6.3× haploid
genome equivalents of grass carp. We selected gene-specific probes for screening the target gene clones in the HindIII library. In all, we obtained 31 positive clones, which were identified for every gene, with an average of 6.2 BAC clones
per gene probe. Thus, we succeeded in constructing the desired BAC libraries, which should provide an important foundation
for future physical mapping and whole-genome sequencing in grass carp. 相似文献
7.
Fang X Gu S Xu Z Chen F Guo D Zhang HB Wu N 《TAG. Theoretical and applied genetics. Theoretische und angewandte Genetik》2004,108(7):1420-1425
A plant-transformation-competent binary BAC library was constructed from the genomic DNA of the chromosome 9 monosomic addition line of Beta corolliflora Zoss. in sugar beet (B. vulgaris. L). This monosomic addition line (designated M14) is characterized by diplosporic reproduction caused by the alien chromosome carrying the gene(s) responsible for diplospory. The library consists of 49,920 clones with an average insert size of 127 kb, representing approximately 7.5 haploid genome equivalents and providing a greater than 99% probability of isolating a single-copy DNA sequence from the library. To develop the scaffold of a physical map for the alien chromosome, B. corolliflora genome-specific dispersed repetitive DNA sequences were used as probes to isolate BAC clones derived from the alien chromosome in the library. A total of 2,365 positive clones were obtained and arrayed into a sublibrary specific for B. corolliflora chromosome 9 (designated bcBAC-IX). The bcBAC-IX sublibrary was further screened with a subtractive cDNA pool generated from the ovules of M14 and the floral buds of B. vulgaris by the suppression subtractive hybridization method. One hundred and three positive binary BACs were obtained, which potentially contain the genes of the alien chromosome specifically expressed during the ovule and embryo development of M14, and may be associated with apomictic reproduction. Thus, these binary BAC clones will be useful for identification of the genes for apomixis by genetic transformation.Communicated by H. C. Becker 相似文献
8.
Generation of a soybean BAC library, and identification of DNA sequences tightly linked to the Rps1-k disease resistance gene 总被引:5,自引:0,他引:5
S. S. Salimath M. K. Bhattacharyya 《TAG. Theoretical and applied genetics. Theoretische und angewandte Genetik》1999,98(5):712-720
A soybean bacterial artificial chromosome (BAC) library, comprising approximately 45 000 clones, was constructed from high-molecular-weight
nuclear DNA of cultivar Williams 82, which carries the Rps1-k gene for resistance against Phytophthora sojae. The library is stored in 130 pools with about 350 clones per pool. Completeness of the library was evaluated for 21 random
sequences including four markers linked to the Rps1 locus and 16 cDNAs. We identified pools containing BACs for all sequences except for one cDNA. Additionally, when screened
for possible contaminating BAC clones carrying chloroplast genes, no sequences homologous to two barley chloroplast genes
were found. The estimated average insert size of the BAC clones was about 105 kb. The library comprises about four genome
equivalents of soybean DNA. Therefore, this gives a probability of 0.98 of finding a specific sequence from this library.
This library should be a useful resource for the positional cloning of Rps1-k, and other soybean genes. We have also evaluated the feasibility of an RFLP-based screening procedure for the isolation
of BAC clones specific for markers that are members of repetitive sequence families, and are linked to the Rps1-k gene. We show that BAC clones isolated for two genetically linked marker loci, Tgmr and TC1-2, are physically linked. Application of this method in expediting the map-based cloning of a gene, especially from
an organism, such as soybean, maize and wheat, with a complex genome is discussed.
Received: 12 May 1998/Accepted: 24 August 1998 相似文献
9.
Two-dimensional screening of the Wageningen chicken BAC library 总被引:10,自引:0,他引:10
Richard P.M.A. Crooijmans Julia Vrebalov Rosilde J.M. Dijkhof Jan J. van der Poel Martien A.M. Groenen 《Mammalian genome》2000,11(5):360-363
We have constructed a Bacterial Artificial Chromosome (BAC) library that provides 5.5-fold redundant coverage of the chicken
genome. The library was made by cloning partial HindIII-digested high-molecular-weight (HMW) DNA of a female White Leghorn chicken into the HindIII site of the vector pECBAC1. Several modifications of standard protocols were necessary to clone efficiently large partial
HindIII DNA fragments. The library consists of 49,920 clones arranged in 130 384-well plates. An average insert size of 134 kb
was estimated from the analysis of 152 randomly selected BAC clones. The average number of NotI restriction sites per clone was 0.77. After individual growth, DNA was isolated of the pooled clones of each 384-well plate,
and subsequently DNA of each plate was isolated from the individual row and column pools. Screening of the Wageningen chicken
BAC library was performed by two-dimensional PCR with 125 microsatellite markers. For 124 markers at least one BAC clone was
obtained. FISH experiments of 108 BAC clones revealed chimerism in less than 1%. The number of different BAC clones per marker
present in the BAC library was examined for 35 markers which resulted in a total of 167 different BAC clones. Per marker the
number of BAC clones varied from 1 to 11, with an average of 4.77. The chicken BAC library constitutes an invaluable tool
for positional cloning and for comparative mapping studies.
Received: 26 October 1999 / Accepted: 6 January 2000 相似文献
10.
A bacterial artificial chromosome (BAC) library of Phytophthora infestans was constructed in a derivative of pBELOBACII that had been modified by adding a npt selectable marker gene for transforming P. infestans. A total library of 8 genome equivalents was generated and 16,128 clones with inserts averaging 75 kb (4.9 genome equivalents) were individually picked and stored as an arrayed library in microtiter plates. This coverage was confirmed by screening the library for 11 DNA loci by colony hybridization and by polymerase chain reaction of DNA pools. Transformation of P. infestans with BAC clones containing inserts of 93 to 135 kb was demonstrated. The efficiency of transformation with most BACs was noticeably higher than that with smaller plasmids. Detailed analyses of transformants obtained with a 102-kb BAC indicated that entire inserts were present in about one-quarter of the transformants. 相似文献
11.
Y. Yu J. P. Tomkins R. Waugh D. A. Frisch D. Kudrna A. Kleinhofs R. S. Brueggeman G. J. Muehlbauer R. P. Wise R. A. Wing 《TAG. Theoretical and applied genetics. Theoretische und angewandte Genetik》2000,101(7):1093-1099
Modern cultivated barley is an important cereal crop with an estimated genome size of 5000 Mb. To develop the resources for
positional cloning and structural genomic analyses in barley, we constructed a bacterial artificial chromosome (BAC) library
for the cultivar Morex using the cloning enzyme HindIII. The library contains 313344 clones (816 384-well plates). A random sampling of 504 clones indicated an average insert
size of 106 kbp (range=30–195 kbp) and 3.4% empty vectors. Screening the colony filters for chloroplast DNA content indicated
an exceptionally low 1.5% contamination with chloroplast DNA. Thus, the library provides 6.3 haploid genome equivalents allowing
a >99% probability of recovering any specific sequence of interest. High-density filters were gridded robotically using a
Genetix Q-BOT in a 4×4 double-spotted array on 22.5-cm2 filters. Each set of 17 filters allows the entire library to be screened with 18432 clones represented per filter. Screening
the library with 40 single copy probes identified an average 6.4 clones per probe, with a range of 1–13 clones per probe.
A set of resistance-gene analog (RGA) sequences identified 121 RGA-containing BAC clones representing 20 different regions
of the genome with an average of 6.1 clones per locus. Additional screening of the library with a P-loop disease resistance
primer probe identified 459 positive BAC clones. These data indicate that this library is a valuable resource for structural
genomic applications in barley.
Received: 20 September 1999 / Accepted: 25 March 2000 相似文献
12.
Construction of BAC and BIBAC libraries from sunflower and identification of linkage group-specific clones by overgo hybridization 总被引:4,自引:0,他引:4
Feng J Vick BA Lee MK Zhang HB Jan CC 《TAG. Theoretical and applied genetics. Theoretische und angewandte Genetik》2006,113(1):23-32
Complementary BAC and BIBAC libraries were constructed from nuclear DNA of sunflower cultivar HA 89. The BAC library, constructed with BamHI in the pECBAC1 vector, contains 107,136 clones and has an average insert size of 140 kb. The BIBAC library was constructed with HindIII in the plant-transformation-competent binary vector pCLD04541 and contains 84,864 clones, with an average insert size of 137 kb. The two libraries combined contain 192,000 clones and are equivalent to approximately 8.9 haploid genomes of sunflower (3,000 Mb/1C), and provide a greater than 99% probability of obtaining a clone of interest. The frequencies of BAC and BIBAC clones carrying chloroplast or mitochondrial DNA sequences were estimated to be 2.35 and 0.04%, respectively, and insert-empty clones were less than 0.5%. To facilitate chromosome engineering and anchor the sunflower genetic map to its chromosomes, one to three single- or low-copy RFLP markers from each linkage group of sunflower were used to design pairs of overlapping oligonucleotides (overgos). Thirty-six overgos were designed and pooled as probes to screen a subset (5.1×) of the BAC and BIBAC libraries. Of the 36 overgos, 33 (92%) gave at least one positive clone and 3 (8%) failed to hit any clone. As a result, 195 BAC and BIBAC clones representing 19 linkage groups were identified, including 76 BAC clones and 119 BIBAC clones, further verifying the genome coverage and utility of the libraries. These BAC and BIBAC libraries and linkage group-specific clones provide resources essential for comprehensive research of the sunflower genome. 相似文献
13.
A bacterial artificial chromosome (BAC) library has been established for Arabidopsis thaliana (ecotype Col-0) covering about seven haploid nuclear genome equivalents. This library, called the Institut für Genbiologische
Forschung (IGF) BAC library, consists of 10 752 recombinant clones carrying inserts (generated by partial EcoRI digestion) of an average size of about 100 kb in a modified BAC vector, pBeloBAC-Kan. Hybridization with organellar DNA
and nuclear repetitive DNA elements revealed the presence of 1.1% clones with mitochondrial DNA, 0.2% clones with plastid
DNA, 3.2% clones with the 180 bp paracentromeric repeat, 1.6% clones with 5S rDNA, and 10.8% clones with the 18S-25S rDNA
repeat. With its extensive genome coverage, its rather uniformly sized inserts (80 kb <85% <120 kb) and low contamination
with organellar DNA, this library provides an excellent resource for A. thaliana genomic mapping, map-based gene cloning, and genome sequencing.
Received: 26 November 1997 / Accepted: 19 February 1998 相似文献
14.
A bacterial artificial chromosome (BAC) library of the genomic DNA of Coprinus cinereus strain MP#2 was constructed using the BAC vector pBACTZ, which carries the C. cinereus trp1 gene. The library consists of 1536 clones. Analysis of inserts in some of the clones suggested that the library covers five times the C. cinereus genome. Screening of the BAC clones using ten markers mapped on nine different chromosomes also indicated that the library is likely to cover the whole length of the genomic DNA. We show an example of transformation of C. cinereus with BACs containing inserts of longer than 170kb. 相似文献
15.
Haiying Liang Eric G. Fang Jeffrey P. Tomkins Meizhong Luo David Kudrna Hye Ran Kim K. Arumuganathan Shaying Zhao James Leebens-Mack Scott E. Schlarbaum Jo Ann Banks Claude W. dePamphilis Dina F. Mandoli Rod A. Wing John E. Carlson 《Tree Genetics & Genomes》2007,3(3):215-225
Liriodendron tulipifera L., a member of the Magnoliaceae, occupies an important phylogenetic position as a basal angiosperm that has retained numerous
putatively ancestral morphological characters, and thus has often been used in studies of the evolution of flowering plants
and of specific gene families. However, genomic resources for these early branching angiosperm lineages are very limited.
In this study, we describe the construction of a large-insert bacterial artificial chromosome (BAC) library from L. tulipifera. Flow cytometry estimates that this nuclear genome is approximately 1,802 Mbp per haploid genome (±16 SD). The BAC library
contains 73,728 clones, a 4.8-fold genome coverage, with an average insert size of 117 kb, a chloroplast DNA content of 0.2%,
and little to no bacterial sequences nor empty vector content clones. As a test of the utility of this BAC library, we screened
the library with six single/low-copy genic probes. We obtained at least two positive clones for each gene and confirmed the
clones by DNA sequencing. A total of 182 paired end sequences were obtained from 96 of the BAC clones. Using BLAST searches,
we found that 25% of the BAC end sequences were similar to DNA sequences in GenBank. Of these, 68% shared sequence with transposable
elements and 25% with genes from other taxa. This result closely reflected the content of random sequences obtained from a
small insert genomic library for L. tulipifera, indicating that the BAC library construction process was not biased. The first genomic DNA sequences for Liriodendron genes are also reported. All the Liriodendron genomic sequences described in this paper have been deposited in the GenBank data library. The end sequences from shotgun
genomic clones and BAC clones are under accession DU169330–DU169684. Partial sequences of Gigantea, Frigida, LEAFY, cinnamyl alcohol dehydrogenase, 4-coumarate:CoA ligase, and phenylalanine ammonia-lyase genes are under accession DQ223429–DQ223434.
Electronic supplementary material Supplementary material is available in the online version of this article at and is accessible for authorized users. 相似文献
16.
Vilanova S Romero C Abernathy D Abbott AG Burgos L Llacer G Badenes ML 《Molecular genetics and genomics : MGG》2003,269(5):685-691
To facilitate gene discovery in the Rosaceae, a bacterial artificial chromosome (BAC) library was constructed using high-molecular-weight (HMW) DNA from apricot leaves ( Prunus armeniaca L.). The library contains 101,376 clones (264, 384-well plates) with an average insert size of 64 kb, equivalent to 22-fold genome coverage. In the first application of this library, high-density filters were screened for self-incompatibility genes using apricot DNA probes. Eight positive BAC clones were detected and fingerprinted to determine clone relationships and assemble contigs. These results demonstrate the suitability of this library for gene identification and physical mapping of the apricot genome.Communicated by R. Hagemann 相似文献
17.
Zhang Y Zhang X Scheuring CF Zhang HB Huan P Li F Xiang J 《Marine biotechnology (New York, N.Y.)》2008,10(4):358-365
Large-insert bacterial artificial chromosome (BAC) libraries are necessary for advanced genetics and genomics research. To facilitate gene cloning and characterization, genome analysis, and physical mapping of scallop, two BAC libraries were constructed from nuclear DNA of Zhikong scallop, Chlamys farreri Jones et Preston. The libraries were constructed in the BamHI and MboI sites of the vector pECBAC1, respectively. The BamHI library consists of 73,728 clones, and approximately 99% of the clones contain scallop nuclear DNA inserts with an average size of 110 kb, covering 8.0x haploid genome equivalents. Similarly, the MboI library consists of 7680 clones, with an average insert of 145 kb and no insert-empty clones, thus providing a genome coverage of 1.1x. The combined libraries collectively contain a total of 81,408 BAC clones arrayed in 212 384-well microtiter plates, representing 9.1x haploid genome equivalents and having a probability of greater than 99% of discovering at least one positive clone with a single-copy sequence. High-density clone filters prepared from a subset of the two libraries were screened with nine pairs of Overgos designed from the cDNA or DNA sequences of six genes involved in the innate immune system of mollusks. Positive clones were identified for every gene, with an average of 5.3 BAC clones per gene probe. These results suggest that the two scallop BAC libraries provide useful tools for gene cloning, genome physical mapping, and large-scale sequencing in the species. 相似文献
18.
Construction of a rice bacterial artificial chromosome library and identification of clones linked to the Xa-21 disease resistance locus 总被引:21,自引:0,他引:21
Guo-Liang Wang Thomas E. Holsten Wen-Yuan Song He-Ping Wang Pamela C. Ronald 《The Plant journal : for cell and molecular biology》1995,7(3):525-533
A bacterial artificial chromosome (BAC) library consisting of 11 000 clones with an average DNA insert size of 125 kb was constructed from rice nuclear DNA. The BAC clones were stable in E. coli after 100 generations of serial growth. Transformation of the BAC clones by electroporation into E. coli was highly efficient and increased with decreasing size of the DNA inserts. The library was evaluated for the presence of organellar, repeated, and telomeric sequences. A very low percentage (<0.3%) of the library consisted of chloroplast and mitochondrial clones. Eighteen BACs were identified that hybridized with an Arabidopsis telomere repeat. Sixteen BACs hybridized with the AA genome-specific repetitive sequence pOs48. Twelve clones were isolated that hybridized with three DNA markers linked to the Xa-21 disease resistance locus. The results indicate that the BAC system can be used to clone and manipulate large pieces of plant DNA efficiently. 相似文献
19.
Silvia V. Diaz-Perez V. Wayne Crouch Marc J. Orbach 《Fungal genetics and biology : FG & B》1996,20(4):280-288
Diaz-Perez, S. V., Crouch, V. W., and Orbach, M. J. 1996. Construction and characterization of aMagnaporthe griseabacterial artificial chromosome library.Fungal Genet. Biol.20,280–288. A bacterial artificial chromosome (BAC) library ofMagnaporthe griseacontaining 4128 clones with an average insert size of 66-kb has been constructed. This library represents seven genome equivalents ofM. griseaand has been demonstrated to be representative of the genome by screening for the presence of several single-copy genes and DNA markers. The utility of the library for use in map-based cloning projects was shown by the spanning of a nine-cosmid, 207-kb DNA contig with only 3 BAC clones. In addition, using alys1-3auxotroph, we have shown that BAC clones at least 113 kb can be transformed intoM. griseato screen for complementation of mutations. Thus, BACs isolated in chromosome walks can be rapidly screened for the presence of the sought after gene. The ease of construction of BAC libraries and of isolation and manipulation of BAC clones makes the BAC system an ideal one for physical analyses of fungal genomes. 相似文献
20.
Construction of a watermelon BAC library and identification of SSRs anchored to melon or Arabidopsis genomes 总被引:4,自引:0,他引:4
Joobeur T Gusmini G Zhang X Levi A Xu Y Wehner TC Oliver M Dean RA 《TAG. Theoretical and applied genetics. Theoretische und angewandte Genetik》2006,112(8):1553-1562
A bacterial artificial chromosome (BAC) library was constructed for watermelon (Citrullus lanatus (Thunb.) Matsum. & Nakai var. lanatus) with an average insert-size of 106 kb, providing 21 haploid genome equivalents. The library was used to identify BAC clones that are anchored to probes evenly distributed on the genomes of melon or Arabidopsis. Twenty eight probes (representing 66% of the tested probes) from melon and 30 probes (65%) from Arabidopsis identified positive BAC clones. Two methods were implemented to identify SSRs from the positively hybridizing BAC clones. First, analysis of BAC end sequences revealed 37 SSRs. For the second method, pooled DNA of BACs identified by the melon probes was used to develop a shotgun library. The library was then screened with synthetic SSR oligonucleotides by hybridization. Sequence analysis of positively hybridizing shotgun clones revealed 142 different SSRs. Thirty eight SSRs were characterized using three watermelon cultivars, five plant introduction (PI) accessions of C. lanatus var lanatus and four PIs of C. lanatus var citroides. Of these, 36 (95%) were found to be polymorphic with up to six alleles per marker. Polymorphism information content values for polymorphic markers varied between 0.22 and 0.79 with an average of 0.53. The methods described herein will be valuable for the construction of a watermelon linkage map with SSRs evenly distributed on its genome that is anchored to the genomes of melon and Arabidopsis. 相似文献