An improved method to identify BAC clones using pooled overgos.
Ontology highlight
ABSTRACT:
SUBMITTER: Madishetty K
PROVIDER: S-EPMC1761434 | biostudies-literature | 2007
REPOSITORIES: biostudies-literature
Publications
An improved method to identify BAC clones using pooled overgos.
Madishetty Kavitha K Condamine Pascal P Svensson Jan T JT Rodriguez Edmundo E Close Timothy J TJ
Nucleic acids research 20061206 1
Hybridization using overgo probes is an established approach for screening arrayed bacterial artificial chromosome (BAC) libraries. We have improved the use of overgos by increasing the yield of positive clones using reduced levels of radioisotopes and enzyme. The strategy involves labeling with all four radiolabeled nucleotides in a hot pulse followed by a cold nucleotide chase and then extending the exposure time to compensate for reduced specific activity of the probes. The resulting cost sav ...[more]
Similar Datasets
Project description:Sequencing of pooled BAC clones from Solanum phureja doubled monoploid clone, DM1-3 516R44 (CIP801092)
| PRJEB2697 | ENA
Project description:BackgroundGenome sequencing of barley has been delayed due to its large genome size (ca. 5,000 Mbp). Among the fast sequencing systems, 454 liquid phase pyrosequencing provides the longest reads and is the most promising method for BAC clones. Here we report the results of pooled sequencing of BAC clones selected with ESTs genetically mapped to chromosome 3H.ResultsWe sequenced pooled barley BAC clones using a 454 parallel genome sequencer. A PCR screening system based on primer sets derived from genetically mapped ESTs on chromosome 3H was used for clone selection in a BAC library developed from cultivar "Haruna Nijo". The DNA samples of 10 or 20 BAC clones were pooled and used for shotgun library development. The homology between contig sequences generated in each pooled library and mapped EST sequences was studied. The number of contigs assigned on chromosome 3H was 372. Their lengths ranged from 1,230 bp to 58,322 bp with an average 14,891 bp. Of these contigs, 240 showed homology and colinearity with the genome sequence of rice chromosome 1. A contig annotation browser supplemented with query search by unique sequence or genetic map position was developed. The identified contigs can be annotated with barley cDNAs and reference sequences on the browser. Homology analysis of these contigs with rice genes indicated that 1,239 rice genes can be assigned to barley contigs by the simple comparison of sequence lengths in both species. Of these genes, 492 are assigned to rice chromosome 1.ConclusionsWe demonstrate the efficiency of sequencing gene rich regions from barley chromosome 3H, with special reference to syntenic relationships with rice chromosome 1.
| S-EPMC3224129 | biostudies-literature
Project description:High resolution BAC array used to study changes in the copy number of chromosome 21 in Acute Meyloid Leukemia patients Genomic DNA from patients as well as from normal donors were differentially labelled and hybridized on the array 36 RPCI-11 BAC clones covering the q-arm of chromosome21 from position15.1MB(close to the centromere)to the telomeric position 46.9 MB with an average gap between clones of 800 kb (range 346-1593 kb)In addition 23 randomly selected clones, each representing 1 of the remaining chromosomes1-20,22,X and YPositions of genes and BAC clones were determined according to the NCBI (http://www.ncbi.nlm.nih.gov/mapview) 59 BAC clones spotted in 6 replicas for a total 354 spots on GAPII corning glass slides using Affymetrix GMS417 Affymetrix Arrayer with 4-ring&pin configuration. (Affymetrix,Santa Clara, CA). Purified clones spotted in 50%DMSO DNA Isolation of these clones was performed from bacterial culture (250ml) using Qiagen midi kit (Qiagen, Valencia CA) gDNA from AML patients and healthy controls was extracted and labelleb according to the published protocol by JR Pollack in Nature Genetics vol.23 Sep.99, also available http://cmgm.stanford.edu/pbrown/protocols/4_genomic.html Fluorescence intensity ratios were measured in control experiments (reference versus reference hybridization) to weight DNA Amplification or deletion Fluorescence ratio >1 indicates amplification, Fluorescence ratio <1 indicate deletion Mean of the background corrected pixel-by-pixel fluorescence ratio between the two dyes at each spot was obtained by genePix software. Series_platform_id: my_array13 Series_submitter weblink: www.dnaarrays.org Keywords: other
2004-02-29 | GSE1078 | GEO
Project description:High resolution BAC array used to study changes in the copy number of chromosome 21 in Acute Meyloid Leukemia patients Genomic DNA from patients as well as from normal donors were differentially labelled and hybridized on the array 36 RPCI-11 BAC clones covering the q-arm of chromosome21 from position15.1MB(close to the centromere)to the telomeric position 46.9 MB with an average gap between clones of 800 kb (range 346-1593 kb)In addition 23 randomly selected clones, each representing 1 of the remaining chromosomes1-20,22,X and YPositions of genes and BAC clones were determined according to the NCBI (http://www.ncbi.nlm.nih.gov/mapview) 59 BAC clones spotted in 6 replicas for a total 354 spots on GAPII corning glass slides using Affymetrix GMS417 Affymetrix Arrayer with 4-ring&pin configuration. (Affymetrix,Santa Clara, CA). Purified clones spotted in 50%DMSO DNA Isolation of these clones was performed from bacterial culture (250ml) using Qiagen midi kit (Qiagen, Valencia CA) gDNA from AML patients and healthy controls was extracted and labelleb according to the published protocol by JR Pollack in Nature Genetics vol.23 Sep.99, also available http://cmgm.stanford.edu/pbrown/protocols/4_genomic.html Fluorescence intensity ratios were measured in control experiments (reference versus reference hybridization) to weight DNA Amplification or deletion Fluorescence ratio >1 indicates amplification, Fluorescence ratio <1 indicate deletion Mean of the background corrected pixel-by-pixel fluorescence ratio between the two dyes at each spot was obtained by genePix software. Series_platform_id: my_array13 Series_submitter weblink: www.dnaarrays.org
2010-06-09 | E-GEOD-1078 | biostudies-arrayexpress
Project description:BAC libraries generated from restriction-digested genomic DNA display representational bias and lack some sequences. To facilitate completion of genome projects, procedures have been developed to create BACs from DNA physically sheared to create fragments extending up to 200 kb. The DNA fragments were repaired to create blunt ends and ligated to a new BAC vector. This approach has been tested by generating BAC libraries from Drosophila DNA with insert lengths between 50 and 150 kb. The libraries lack chimeric clone problems as determined by mapping paired BAC-end sequences to the assembled fly genome sequence. The utility of "sheared" libraries was demonstrated by closure of a previous clone gap and by isolation of clones from telomeric regions, which were notably absent from previous Drosophila BAC libraries.
| S-EPMC1909752 | biostudies-literature
Project description:A practical way to reduce the cost of surveying single-nucleotide polymorphism (SNP) in a large number of individuals is to measure the allele frequencies in pooled DNA samples. Pyrosequencing(TM) has been frequently used for this application because signals generated by this approach are proportional to the amount of DNA templates. The Pyrosequencing(TM) pyrogram is determined by the dispensing order of dNTPs, which is usually designed based on the known SNPs to avoid asynchronistic extensions of heterozygous sequences. Therefore, utilizing the pyrogram signals to identify de novo SNPs in DNA pools has never been undertook. Here, in this study we developed an algorithm to address this issue. With the sequence and pyrogram of the wild-type allele known in advance, we could use the pyrogram obtained from the pooled DNA sample to predict the sequence of the unknown mutant allele (de novo SNP) and estimate its allele frequency. Both computational simulation and experimental Pyrosequencing(TM) test results suggested that our method performs well. The web interface of our method is available at http://life.nctu.edu.tw/?yslin/PSM/.
| S-EPMC3061071 | biostudies-literature
Project description:Using the human bacterial artificial chromosome (BAC) fingerprint-based physical map, genome sequence assembly and BAC end sequences, we have generated a fingerprint-validated set of 32 855 BAC clones spanning the human genome. The clone set provides coverage for at least 98% of the human fingerprint map, 99% of the current assembled sequence and has an effective resolving power of 79 kb. We have made the clone set publicly available, anticipating that it will generally facilitate FISH or array-CGH-based identification and characterization of chromosomal alterations relevant to disease.
| S-EPMC484185 | biostudies-literature
Project description:Chinese hamster ovary (CHO) cells have frequently been used in biotechnology as a mammalian host cell platform for expressing genes of interest. Previously, we constructed a detailed physical chromosomal map of the CHO DG44 cell line by fluorescence in situ hybridization (FISH) imaging using 303 bacterial artificial chromosome (BAC) clones as hybridization probes (BAC-FISH). BAC-FISH results revealed that the two longest chromosomes were completely paired. However, other chromosomes featured partial deletions or rearrangements. In this study, we determined the end sequences of 303 BAC clones (BAC end sequences), which were used for BAC-FISH probes. Among 606 BAC-end sequences (BESs) (forward and reverse ends), 558 could be determined. We performed a comparison between all determined BESs and mouse genome sequences using NCBI BLAST. Among these 558 BESs, 465 showed high homology to mouse chromosomal sequences. We analyzed the locations of these BACs in chromosomes of the CHO DG44 cell line using a physical chromosomal map. From the obtained results, we investigated the regional similarities among CHO chromosomes (A-T) and mouse chromosomes (1-19 and sex) about 217 BESs (46.7% of 465 high homologous BESs). Twenty-three specific narrow regions in 13 chromosomes of the CHO DG44 cell line showed high homology to mouse chromosomes, but most of other regions did not show significant correlations with the mouse genome. These results contribute to accurate alignments of chromosomes of Chinese hamster and its genome sequence, analysis of chromosomal instability in CHO cells, and the development of target locations for gene and/or genome editing techniques.
| S-EPMC6214854 | biostudies-literature
Project description:The Festuca genus is thought to be the most numerous genus of the Poaceae family. One of the most agronomically important forage grasses, Festuca pratensis Huds. is treated as a model plant to study the molecular mechanisms associated with tolerance to winter stresses, including frost. However, the precise mapping of the genes governing stress tolerance in this species is difficult as its karyotype remains unrecognized. Only two F. pratensis chromosomes with 35S and 5S rDNA sequences can be easily identified, but its remaining chromosomes have not been distinguished to date. Here, two libraries derived from F. pratensis nuclear DNA with various contents of repetitive DNA sequences were used as sources of molecular probes for fluorescent in situ hybridisation (FISH), a BAC library and a library representing sequences most frequently present in the F. pratensis genome. Using FISH, six groups of DNA sequences were revealed in chromosomes on the basis of their signal position, including dispersed-like sequences, chromosome painting-like sequences, centromeric-like sequences, knob-like sequences, a group without hybridization signals, and single locus-like sequences. The last group was exploited to develop cytogenetic maps of diploid and tetraploid F. pratensis, which are presented here for the first time and provide a remarkable progress in karyotype characterization.
| S-EPMC5462415 | biostudies-literature
Project description:Two bacterial artificial chromosome (BAC) clones (350B21 and 299N22) of Pima 90-53 cotton [Gossypium barbadense Linnaeus, 1753 (2n=4x=52)] were screened from a BAC library using SSR markers. Strong hybridization signals were detected at terminal regions of all A genome (sub-genome) chromosomes, but were almost absent in D genome (sub-genome) chromosomes with BAC clone 350B21 as the probe. The results indicate that specific sequences, which only exist at the terminal parts of A genome (sub-genome) chromosomes with a huge repeat number, may be contained in BAC clone 350B21. When utilizing FISH with the BAC clone 299N22 as probe, a pair of obvious signals was detected on chromosome 13 of D genome (sub-genome), while strong dispersed signals were detected on all A genome (sub-genome) chromosomes. The results showed that peculiar repetitive sequence, which was distributed throughout all A genome (sub-genome) chromosomes, may exist in BAC clone 299N22. The absence of the repetitive sequences, which exist in the two BAC clones, in D genome may account for the genome-size variation between A and D genomes. In addition, the microcolinearity analysis of the clone 299N22 and its homologous region on Gossypium raimondii Ulbrich, 1932 chromosome 13 (D513) indicated that the clone 299N22 might come from A sub-genome of sea island cotton (Gossypium barbadense), and a huge number of small deletions, illegitimate recombination, translocation and rearrangements may have occurred during the genus evolution. The two BAC clones studied here can be used as cytological markers but will be also be helpful to research in cotton genome evolution and comparative genomics.
| S-EPMC4856921 | biostudies-other