Construction of a bacterial artificial chromosome (BAC) library for potato molecular cytogenetics research

Genome ◽  
2000 ◽  
Vol 43 (1) ◽  
pp. 199-204 ◽  
Author(s):  
Junqi Song ◽  
Fenggao Dong ◽  
Jiming Jiang

Lack of reliable techniques for chromosome identification is the major obstacle for cytogenetics research in plant species with large numbers of small chromosomes. To promote molecular cytogenetics research of potato (Solanum tuberosum, 2n = 4x = 48) we developed a bacterial artificial chromosome (BAC) library of a diploid potato species S. bulbocastanum. The library consists of 23 808 clones with an average insert size of 155 kb, and represents approximately 3.7 equivalents to the potato genome. The majority of the clones in the BAC library generated distinct signals on specific potato chromosomes using fluorescence in situ hybridization (FISH). The hybridization signals provide excellent cytological markers to tag individual potato chromosomes. We also demonstrated that the BAC clones can be mapped to specific positions on meiotic pachytene chromosomes. The excellent resolution of pachytene FISH can be used to construct a physical map of potato by mapping molecular marker-targeted BAC clones on pachytene chromosomes. Key words: potato, BAC library, chromosome identification, physical mapping, molecular cytogenetics.

Genome ◽  
2004 ◽  
Vol 47 (2) ◽  
pp. 239-245 ◽  
Author(s):  
Yaping Qian ◽  
Li Jin ◽  
Bing Su

The large-insert genomic DNA library is a critical resource for genome-wide genetic dissection of target species. We constructed a high-redundancy bacterial artificial chromosome (BAC) library of a New World monkey species, the black-handed spider monkey (Ateles geoffroyi). A total of 193 152 BAC clones were generated in this library. The average insert size of the BAC clones was estimated to be 184.6 kb with the small inserts (50-100 kb) accounting for less than 3% and the non-recombinant clones only 1.2%. Assuming a similar genome size with humans, the spider monkey BAC library has about 11× genome coverage. In addition, by end sequencing of randomly selected BAC clones, we generated 367 sequence tags for the library. When blasted against human genome, they showed a good correlation between the number of hit clones and the size of the chromosomes, an indication of unbiased chromosomal distribution of the library. This black-handed spider monkey BAC library would serve as a valuable resource in comparative genomic study and large-scale genome sequencing of nonhuman primates.Key words: black-handed spider monkeys, Ateles geoffroyi, BAC library.


2013 ◽  
Vol 2013 ◽  
pp. 1-7 ◽  
Author(s):  
Changqing Liu ◽  
Yuo Guo ◽  
Taofeng Lu ◽  
Hongmei Wu ◽  
Risu Na ◽  
...  

Bacterial artificial chromosome (BAC) libraries have been invaluable tools for the genome-wide genetic dissection of complex organisms. Here, we report the construction and characterization of a high-redundancy BAC library from a very valuable pig breed in China, Wuzhishan miniature pig (Sus scrofa), using its blood cells and fibroblasts, respectively. The library contains approximately 153,600 clones ordered in 40 superpools of 10 × 384-deep well microplates. The average insert size of BAC clones was estimated to be 152.3 kb, representing approximately 7.68 genome equivalents of the porcine haploid genome and a 99.93% statistical probability of obtaining at least one clone containing a unique DNA sequence in the library. 19 pairs of microsatellite marker primers covering porcine chromosomes were used for screening the BAC library, which showed that each of these markers was positive in the library; the positive clone number was 2 to 9, and the average number was 7.89, which was consistent with 7.68-fold coverage of the porcine genome. And there were no significant differences of genomic BAC library from blood cells and fibroblast cells. Therefore, we identified 19 microsatellite markers that could potentially be used as genetic markers. As a result, this BAC library will serve as a valuable resource for gene identification, physical mapping, and comparative genomics and large-scale genome sequencing in the porcine.


Genome ◽  
2010 ◽  
Vol 53 (9) ◽  
pp. 667-674 ◽  
Author(s):  
Xiangzong Meng ◽  
Binbin Huang ◽  
Liangliang Zhou ◽  
Yunxia He ◽  
Qi Chen ◽  
...  

Coix lacryma-jobi L. (Coix) is a close relative of maize and is considered a valuable genetic resource for crop improvement. Here we report the construction of the first Coix bacterial artificial chromosome (BAC) library using accession PI 324059. This BAC library contains about 230 400 clones with an average insert size of 113 kb, has low organellar DNA contamination, and provides 16.3-fold coverage of the genome. The library was stored in 12 × 96 pools that could be screened with a PCR protocol. Library screening was performed for the 22 kDa α-coixin gene family. A total of 57 positive pools were identified, and single clones were isolated from 19 of these pools. Based on DNA fingerprinting and Southern blot analysis, these 19 BAC clones form a single contig of about 340 kb in length, indicating that the 22 kDa α-coixin genes occur in a cluster. These results demonstrated the suitability of this BAC library for gene isolation and comparative genomics studies of the Coix genome.


Genome ◽  
2006 ◽  
Vol 49 (11) ◽  
pp. 1393-1398 ◽  
Author(s):  
X.F. Wang ◽  
J. Ma ◽  
W.S. Wang ◽  
Y.M. Zheng ◽  
G.Y. Zhang ◽  
...  

As the second most widely cultivated cotton, Gossypium barbadense is well known for its superior fiber properties and its high levels of resistance to Fusarium and Verticillium wilts. To enhance our ability to exploit these properties in breeding programs, we constructed the first bacterial artificial chromosome (BAC) library for this species. The library contains 167 424 clones (49 920 BamHI and 117 504 HindIII clones), with an estimated average insert size of 130 kb. About 94.0% of the clones had inserts over 100 kb, and the empty clones accounted for less than 4.0%. Contamination of the library with chloroplast clones was very low (0.2%). Screening the library with locus-specific probes showed that BAC clones represent 6.5-fold genome equivalents. This high-quality library provides an additional asset with which to exploit genetic variation for cotton improvement.


Genome ◽  
2017 ◽  
Vol 60 (4) ◽  
pp. 310-324 ◽  
Author(s):  
Brad S. Coates ◽  
Craig A. Abel ◽  
Omaththage P. Perera

The lepidopteran pest insect Helicoverpa zea feeds on cultivated corn and cotton across the Americas where control remains challenging owing to the evolution of resistance to chemical and transgenic insecticidal toxins, yet genomic resources remain scarce for this species. A bacterial artificial chromosome (BAC) library having a mean genomic insert size of 145 ± 20 kbp was created from a laboratory strain of H. zea, which provides ∼12.9-fold coverage of a 362.8 ± 8.8 Mbp (0.37 ± 0.09 pg) flow cytometry estimated haploid genome size. Assembly of Illumina HiSeq 2000 reads generated from 14 pools that encompassed all BAC clones resulted in 165 485 genomic contigs (N50 = 3262 bp; 324.6 Mbp total). Long terminal repeat (LTR) protein coding regions annotated from 181 contigs included 30 Ty1/copia, 78 Ty3/gypsy, and 73 BEL/Pao elements, of which 60 (33.1%) encoded all five functional polyprotein (pol) domains. Approximately 14% of LTR elements are distributed non-randomly across pools of BAC clones.


Genome ◽  
2004 ◽  
Vol 47 (6) ◽  
pp. 1182-1191 ◽  
Author(s):  
Jan Šafář ◽  
Juan Carlos Noa-Carrazana ◽  
Jan Vrána ◽  
Jan Bartoš ◽  
Olena Alkhimova ◽  
...  

The first bacterial artificial chromosome (BAC) library of the banana species Musa balbisiana 'Pisang Klutuk Wulung' (PKW BAC library) was constructed and characterized. One improved and one novel protocol for nuclei isolation were employed to overcome problems caused by high levels of polyphenols and polysaccharides present in leaf tissues. The use of flow cytometry to purify cell nuclei eliminated contamination with secondary metabolites and plastid DNA. Furthermore, the usefulness of the inducible pCC1BAC vector to obtain a higher amount of BAC DNA was demonstrated. The PKW BAC library represents nine haploid genome equivalents of M. balbisiana and its mean insert size is 135 kb. It consists of two sublibraries, of which the first one (SN sublibrary with 24 960 clones) was prepared according to an improved standard nuclei isolation protocol, whereas the second (FN sublibrary with 11 904 clones) was obtained from flow-sorted nuclei. Screening with 12 RFLP probes, which were genetically anchored to 8 genetic linkage groups of the banana species Musa acuminata, revealed an average of 11 BAC clones per probe, thus confirming the genome coverage estimated based on the insert size, as well as a high level of conservation between the two species of Musa. Localization of selected BAC clones to mitotic chromosomes using FISH indicated that the BAC library represented a useful resource for cytogenetic mapping. As the first step in map-based cloning of a genetic factor that is involved in the activation of integrated pararetroviral sequences of Banana streak virus (BSV), the BSV expressed locus (BEL) was physically delimited. The PKW BAC library represents a publicly available tool, and is currently used to reveal the integration and activation mechanisms of BSV sequences and to study banana genome structure and evolution.Key words: bacterial artificial chromosome library, banana, BAC-FISH, flow cytometry, Musa balbisiana, Banana streak virus, BSV.


Genome ◽  
1999 ◽  
Vol 42 (6) ◽  
pp. 1176-1182 ◽  
Author(s):  
D Lijavetzky ◽  
G Muzzi ◽  
T Wicker ◽  
B Keller ◽  
R Wing ◽  
...  

A genomic bacterial artificial chromosome (BAC) library of the A genome of wheat has been constructed. Triticum monococcum accession DV92 was selected for this purpose because it is a cultivated diploid wheat and one of the parental lines used in the construction of a saturated genetic map. Leaves from this accession were used to isolate high-molecular-weight DNA from nuclei. This DNA was partially digested with restriction enzyme Hind III, subjected to double size selection, electroeluted and cloned into the pINDIGO451 BAC vector. The library consists of 276 480 clones with an average insert size of 115 kb. Excluding the 1.33% of empty clones and 0.14% of clones with chloroplast DNA, the coverage of this library is 5.6 genome equivalents. With this genome coverage the probability of having any DNA sequence represented in this library is higher than 99.6%. Clones were sorted in 720 384-well plates and blotted onto 15 high-density filters. High-density filters were screened with several single or low-copy clones and five positive BAC clones were selected for further analysis. Since most of the T. monococcum BAC ends included repetitive sequences, a modification was introduced into the classical end-isolation procedure to select low copy sequences for chromosome walking.Key words: bacterial artificial chromosome, BAC library, Triticum monococcum, wheat.


2005 ◽  
Vol 53 (6) ◽  
pp. 389 ◽  
Author(s):  
Natasha Sankovic ◽  
Wayne Bawden ◽  
John Martyn ◽  
Jennifer A. M. Graves ◽  
Kurt Zuelke

With the accelerating recognition of the power of comparative genomics, there is now enormous interest in sequencing the genomes of a broad range of species. Marsupials diverged at an important evolutionary time. The model Australian marsupial, the tammar wallaby (Macropus eugenii), has long been a resource for biological and genetic studies of marsupials, and the availability of a bacterial artificial chromosome (BAC) library will be a valuable resource in these studies. A tammar wallaby BAC library was constructed using pRazorBAC vector. It contains 55 296 clones with an average insert size of 108 kb, representing 2.2 times coverage of the wallaby genome (based on an estimated 2.7 × 109 bp haploid genome size). The library was arrayed in 384-well plates, and spotted in duplicate onto nylon membranes. Screening these membranes has yielded clones containing 34 single-copy genes distributed over the genome, while it failed for only one gene. Each probe isolated 1–12 BAC clones and, to date, no chimeric clones have been found. This BAC library will constitute an invaluable resource for creating physical maps, positional cloning of genes and other sequences in the tammar wallaby, as well as comparative mapping studies in mammals.


2012 ◽  
Vol 2012 ◽  
pp. 1-4 ◽  
Author(s):  
K. W. Airmet ◽  
J. D. Hinckley ◽  
L. T. Tree ◽  
M. Moss ◽  
S. Blumell ◽  
...  

The Ilama is an important agricultural livestock in much of South America. The llama is increasing in popularity in the United States as a companion animal. Little work has been done to improve llama production using modern technology. A paucity of information is available regarding the llama genome. We report the construction of a llama bacterial artificial chromosome (BAC) library of about 196,224 clones in the vector pECBAC1. Using flow cytometry and bovine, human, mouse, and chicken as controls, we determined the llama genome size to be2.4×109 bp. The average insert size of the library is 137.8 kb corresponding to approximately 9-fold genome coverage. Further studies are needed to further characterize the library and llama genome. We anticipate that this new library will help facilitate future genomic studies in the llama.


1998 ◽  
Vol 66 (5) ◽  
pp. 2221-2229 ◽  
Author(s):  
Roland Brosch ◽  
Stephen V. Gordon ◽  
Alain Billault ◽  
Thierry Garnier ◽  
Karin Eiglmeier ◽  
...  

ABSTRACT The bacterial artificial chromosome (BAC) cloning system is capable of stably propagating large, complex DNA inserts in Escherichia coli. As part of the Mycobacterium tuberculosis H37Rv genome sequencing project, a BAC library was constructed in the pBeloBAC11 vector and used for genome mapping, confirmation of sequence assembly, and sequencing. The library contains about 5,000 BAC clones, with inserts ranging in size from 25 to 104 kb, representing theoretically a 70-fold coverage of the M. tuberculosisgenome (4.4 Mb). A total of 840 sequences from the T7 and SP6 termini of 420 BACs were determined and compared to those of a partial genomic database. These sequences showed excellent correlation between the estimated sizes and positions of the BAC clones and the sizes and positions of previously sequenced cosmids and the resulting contigs. Many BAC clones represent linking clones between sequenced cosmids, allowing full coverage of the H37Rv chromosome, and they are now being shotgun sequenced in the framework of the H37Rv sequencing project. Also, no chimeric, deleted, or rearranged BAC clones were detected, which was of major importance for the correct mapping and assembly of the H37Rv sequence. The minimal overlapping set contains 68 unique BAC clones and spans the whole H37Rv chromosome with the exception of a single gap of ∼150 kb. As a postgenomic application, the canonical BAC set was used in a comparative study to reveal chromosomal polymorphisms between M. tuberculosis, M. bovis, and M. bovis BCG Pasteur, and a novel 12.7-kb segment present in M. tuberculosis but absent from M. bovis and M. bovis BCG was characterized. This region contains a set of genes whose products show low similarity to proteins involved in polysaccharide biosynthesis. The H37Rv BAC library therefore provides us with a powerful tool both for the generation and confirmation of sequence data as well as for comparative genomics and other postgenomic applications. It represents a major resource for present and future M. tuberculosis research projects.


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