Soybean genomic survey: BAC-end sequences near RFLP and SSR markers

Genome ◽  
2001 ◽  
Vol 44 (4) ◽  
pp. 572-581 ◽  
Author(s):  
Laura Fredrick Marek ◽  
Joann Mudge ◽  
Laura Darnielle ◽  
David Grant ◽  
Nadja Hanson ◽  
...  
Keyword(s):  
Physical Map ◽  
Repetitive Sequences ◽  
Genome Structure ◽  
Soybean Genome ◽  
Bacterial Artificial Chromosomes ◽  
University Of Minnesota ◽  
Artificial Chromosomes ◽  
Metabolic Functions ◽  
Wide Range ◽  
End Sequences

We are building a framework physical infrastructure across the soybean genome by using SSR (simple sequence repeat) and RFLP (restriction fragment length polymorphism) markers to identify BACs (bacterial artificial chromosomes) from two soybean BAC libraries. The libraries were prepared from two genotypes, each digested with a different restriction enzyme. The BACs identified by each marker were grouped into contigs. We have obtained BAC-end sequence from BACs within each contig. The sequences were analyzed by the University of Minnesota Center for Computational Genomics and Bioinformatics using BLAST algorithms to search nucleotide and protein databases. The SSR-identified BACs had a higher percentage of significant BLAST hits than did the RFLP-identified BACs. This difference was due to a higher percentage of hits to repetitive-type sequences for the SSR-identified BACs that was offset in part, however, by a somewhat larger proportion of RFLP-identified significant hits with similarity to experimentally defined genes and soybean ESTs (expressed sequence tags). These genes represented a wide range of metabolic functions. In these analyses, only repetitive sequences from SSR-identified contigs appeared to be clustered. The BAC-end sequences also allowed us to identify microsynteny between soybean and the model plants Arabidopsis thaliana and Medicago truncatula. This map-based approach to genome sampling provides a means of assaying soybean genome structure and organization.Key words: Glycine max, sequencing, physical map, contig.

Segmental duplications within the Glycine max genome revealed by fluorescence in situ hybridization of bacterial artificial chromosomes

Genome ◽  
2004 ◽  
Vol 47 (4) ◽  
pp. 764-768 ◽  
Author(s):  
Janice Pagel ◽  
Jason G Walling ◽  
Nevin D Young ◽  
Randy C Shoemaker ◽  
Scott A Jackson
Keyword(s):  
In Situ Hybridization ◽  
Glycine Max ◽  
Repetitive Sequences ◽  
Genome Structure ◽  
Soybean Genome ◽  
Structure Evolution ◽  
Segmental Duplications ◽  
Bacterial Artificial Chromosomes ◽  
Artificial Chromosomes

Soybean (Glycine max L. Merr.) is presumed to be an ancient polyploid based on chromosome number and multiple RFLP fragments in genetic mapping. Direct cytogenetic observation of duplicated regions within the soybean genome has not heretofore been reported. Employing flourescence in situ hybridization (FISH) of genetically anchored bacterial artificial chromosomes (BACs) in soybean, we were able to observe that the distal ends of molecular linkage group E had duplicated regions on linkage groups A2 and B2. Further, using fiber-FISH, it was possible to measure the molecular size and organization of one of the duplicated regions. As FISH did not require repetitive DNA for blocking fluorescence signals, we assume that the 200-kb genome region is relatively low in repetitive sequences. This observation, along with the observation that the BACs are located in distal euchromatin regions, has implications for genome structure/evolution and the approach used to sequence the soybean genome.Key words: soybean, genome evolution, FISH, chromosomes, physical mapping.

scholarly journals Molecular characterization of the duplicated meristem identity genes HvAP1a and HvAP1b in barley

Genome ◽  
2005 ◽  
Vol 48 (5) ◽  
pp. 905-912 ◽  
Author(s):  
Liuling Yan ◽  
Jarislav von Zitzewitz ◽  
Jeffrey S Skinner ◽  
Patrick M Hayes ◽  
Jorge Dubcovsky
Keyword(s):  
Structural Changes ◽  
Growth Habit ◽  
Physical Map ◽  
Single Copy ◽  
Bacterial Artificial Chromosomes ◽  
Vernalization Gene ◽  
Artificial Chromosomes ◽  
Physical Maps ◽  
Meristem Identity

The vernalization gene VRN-1 has been identified as a MADS-box transcription factor orthologous to the meristem identity gene APETALA1 (AP1). A single copy of this gene was found in diploid wheat, but 2 copies were reported in barley. In this study, we present a detailed characterization of these 2 copies to understand their respective roles in the vernalization response. We identified 2 groups of barley bacterial artificial chromosomes (BACs), each containing 1 AP1 copy designated hereafter as HvAP1a and HvAP1b. A physical map of the VRN-H1 region showed that the HvAP1a BACs were part of the VRN-H1 region but that the HvAP1b BACs were not. Numerous structural changes were observed between the barley and wheat VRN-1 physical maps. In a population segregating for VRN-H1, the HvAP1a gene cosegregated with growth habit, suggesting that HvAP1a is the barley vernalization gene VRN-H1. The other copy, HvAP1b, was mapped on the centromeric region of chromosome 1H, the chromosome where vernalization gene VRN-H3 was previously mapped. We developed a mapping population segregating for VRN-H3 and showed that 2 molecular makers flanking HvAP1b locus were not linked to growth habit. The HvAP1b copy has a complete deletion of the first 2 exons, suggesting that it is a truncated pseudogene and not a candidate for VRN-H3. In summary, this study contributed a detailed physical map of the barley VRN-H1 region, showed several structural differences with the orthologous wheat region, and clarified the identity of the barley VRN-H1 gene.Key words: barley, vernalization, Vrn-1, physical map.

Survey sequencing of soybean elucidates the genome structure, composition and identifies novel repeats

2006 ◽  
Vol 33 (8) ◽  
pp. 765 ◽  
Author(s):  
Andrew Nunberg ◽  
Joseph A. Bedell ◽  
Mohammad A. Budiman ◽  
Robert W. Citek ◽  
Sandra W. Clifton ◽  
...  
Keyword(s):  
Genome Structure ◽  
Artificial Chromosome ◽  
Repeat Sequence ◽  
Soybean Genome ◽  
Dna Repeats ◽  
Gene Enrichment ◽  
Dna Repeat ◽  
Glycine Max L ◽  
Soybean Gene ◽  
End Sequences

In order to expand our knowledge of the soybean genome and to create a useful DNA repeat sequence database, over 24 000 DNA fragments from a soybean [Glycine max (L.) Merr.] cv. Williams 82 genomic shotgun library were sequenced. Additional sequences came from over 29 000 bacterial artificial chromosome (BAC) end sequences derived from a BstI library of the cv. Williams 82 genome. Analysis of these sequences identified 348 different DNA repeats, many of which appear to be novel. To extend the utility of the work, a pilot study was also conducted using methylation filtration to estimate the hypomethylated, soybean gene space. A comparison between 8366 sequences obtained from a filtered library and 23 788 from an unfiltered library indicate a gene-enrichment of ~3.2-fold in the hypomethylated sequences. Given the 1.1-Gb soybean genome, our analysis predicts a ~343-Mb hypomethylated, gene-rich space.

Framework for a Physical Map of the Human 22q13 Region Using Bacterial Artificial Chromosomes (BACs)

Genomics ◽  
1996 ◽  
Vol 33 (1) ◽  
pp. 9-20 ◽  
Author(s):  
Holger Schmitt ◽  
Ung-Jin Kim ◽  
Tatiana Slepak ◽  
Nikolaus Blin ◽  
Melvin I. Simon ◽  
...  
Keyword(s):  
Physical Map ◽  
Bacterial Artificial Chromosomes ◽  
Artificial Chromosomes

scholarly journals Mapping of Micro-Tom BAC-End Sequences to the Reference Tomato Genome Reveals Possible Genome Rearrangements and Polymorphisms

2012 ◽  
Vol 2012 ◽  
pp. 1-8 ◽  
Author(s):  
Erika Asamizu ◽  
Kenta Shirasawa ◽  
Hideki Hirakawa ◽  
Shusei Sato ◽  
Satoshi Tabata ◽  
...  
Keyword(s):  
Physical Map ◽  
Repetitive Sequences ◽  
Genome Rearrangements ◽  
Chromosome 2 ◽  
Tomato Genome ◽  
Bac Contig ◽  
Entire Genome ◽  
End Sequences ◽  
Standard Cultivar ◽  
Bac Contigs

A total of 93,682 BAC-end sequences (BESs) were generated from a dwarf model tomato, cv. Micro-Tom. After removing repetitive sequences, the BESs were similarity searched against the reference tomato genome of a standard cultivar, “Heinz 1706.” By referring to the “Heinz 1706” physical map and by eliminating redundant or nonsignificant hits, 28,804 “unique pair ends” and 8,263 “unique ends” were selected to construct hypothetical BAC contigs. The total physical length of the BAC contigs was 495, 833, 423 bp, covering 65.3% of the entire genome. The average coverage of euchromatin and heterochromatin was 58.9% and 67.3%, respectively. From this analysis, two possible genome rearrangements were identified: one in chromosome 2 (inversion) and the other in chromosome 3 (inversion and translocation). Polymorphisms (SNPs and Indels) between the two cultivars were identified from the BLAST alignments. As a result, 171,792 polymorphisms were mapped on 12 chromosomes. Among these, 30,930 polymorphisms were found in euchromatin (1 per 3,565 bp) and 140,862 were found in heterochromatin (1 per 2,737 bp). The average polymorphism density in the genome was 1 polymorphism per 2,886 bp. To facilitate the use of these data in Micro-Tom research, the BAC contig and polymorphism information are available in the TOMATOMICS database.

scholarly journals Computational Tools forBrassica–ArabidopsisComparative Genomics

2005 ◽  
Vol 6 (3) ◽  
pp. 147-152 ◽  
Author(s):  
Paul Beckett ◽  
Ian Bancroft ◽  
Martin Trick
Keyword(s):  
Genome Sequence ◽  
In Silico ◽  
Physical Map ◽  
Genome Structure ◽  
Genome Project ◽  
Genome Survey ◽  
Physical Maps ◽  
Alignment Tool ◽  
Wide Range ◽  
Survey Sequence

Recent advances, such as the availability of extensive genome survey sequence (GSS) data and draft physical maps, are radically transforming the means by which we can dissectBrassicagenome structure and systematically relate it to theArabidopsismodel. Hitherto, our view of the co-linearities between these closely related genomes had been largely inferred from comparative RFLP data, necessitating substantial interpolation and expert interpretation. Sequencing of theBrassica rapagenome by the MultinationalBrassicaGenome Project will, however, enable an entirely computational approach to this problem. Meanwhile we have been developing databases and bioinformatics tools to support our work inBrassicacomparative genomics, including a recently completed draft physical map ofB. rapaintegrated with anchor probes derived from theArabidopsisgenome sequence. We are also exploring new ways to display the emergingBrassica–Arabidopsissequence homology data. We have mapped all publicly available Brassica sequencesin silicoto theArabidopsisTIGR v5 genome sequence and published this in the ATIDB database that uses Generic Genome Browser (GBrowse). Thisin silicoapproach potentially identifies all paralogous sequences and so we colour-code the significance of the mappings and offer an integrated, real-time multiple alignment tool to partition them into paralogous groups. The MySQL database driving GBrowse can also be directly interrogated, using the powerful API offered by the Perl Bio∷DB∷GFF methods, facilitating a wide range of data-mining possibilities.

Wheat genome structure and function: genome sequence data and the International Wheat Genome Sequencing Consortium

2007 ◽  
Vol 58 (6) ◽  
pp. 470 ◽  
Author(s):  
P. Moolhuijzen ◽  
D. S. Dunn ◽  
M. Bellgard ◽  
M. Carter ◽  
J. Jia ◽  
...  
Keyword(s):  
Genome Sequencing ◽  
Physical Map ◽  
Genome Structure ◽  
Genetic Research ◽  
Structure And Function ◽  
Wheat Genome ◽  
D Genome ◽  
Genome Sequencing Consortium ◽  
And Function ◽  
Bac Contigs

Genome sequencing and the associated bioinformatics is now a widely accepted research tool for accelerating genetic research and the analysis of genome structure and function of wheat because it leverages similar work from other crops and plants. The International Wheat Genome Sequencing Consortium addresses the challenge of wheat genome structure and function and builds on the research efforts of Professor Bob McIntosh in the genetics of wheat. Currently, expressed sequence tags (ESTs; ~500 000 to date) are the largest sequence resource for wheat genome analyses. It is estimated that the gene coverage of the wheat EST collection is ~60%, close to that of Arabidopsis, indicating that ~40% of wheat genes are not represented in EST collections. The physical map of the D-genome donor species Aegilops tauschii is under construction (http://wheat.pw.usda.gov/PhysicalMapping). The technologies developed in this analysis of the D genome provide a good model for the approach to the entire wheat genome, namely compiling BAC contigs, assigning these BAC contigs to addresses in a high resolution genetic map, filling in gaps to obtain the entire physical length of a chromosome, and then large-scale sequencing.

Prescribed burning for lowland black spruce regeneration in northern Minnesota

1984 ◽  
Vol 14 (1) ◽  
pp. 107-113 ◽  
Author(s):  
Scott E. Aksamit ◽  
Frank D. Irving
Keyword(s):  
Prescribed Burning ◽  
Black Spruce ◽  
Controlled Study ◽  
University Of Minnesota ◽  
Feather Moss ◽  
Wide Range ◽  
Labrador Tea ◽  
Tall Shrub ◽  
The University ◽  
Larger Sample

Concern over the variability of black spruce (Piceamariana (Mill.) B.S.P.) regeneration on peatlands in northern Minnesota following prescribed burning led to a cooperative study between the University of Minnesota and the Minnesota Department of Natural Resources. Twenty-seven black spruce cutovers on State lands that had been prescribed burned and either seeded or left to regenerate naturally were sampled. These were stratified into sphagnum – Labrador-tea – leather-leaf (SPHG) sites (10), feather moss (FM) sites (9), and alder – graminoid – other tall shrub (ALDR) sites (8). Results indicate that fire was not necessary to regenerate SPHG sites. FM sites required fire to modify unfavorable seedbeds and to reduce competition. Best results were obtained by burning when the upper layers of the peat were highly desiccated. ALDR sites occupied a wide range of ecological conditions which led to highly variable regeneration results. A larger sample size and possibly more carefully controlled study conditions are needed to fully understand ALDR site regeneration. Seeding results were uncertain for all sites.

scholarly journals A Classification of Basic Helix-Loop-Helix Transcription Factors of Soybean

2015 ◽  
Vol 2015 ◽  
pp. 1-10 ◽  
Author(s):  
Karen A. Hudson ◽  
Matthew E. Hudson
Keyword(s):  
Transcription Factors ◽  
Genome Sequence ◽  
Search Algorithm ◽  
Soybean Genome ◽  
Binding Potential ◽  
Future Research ◽  
Basic Helix Loop Helix ◽  
Helix Loop Helix ◽  
Bhlh Genes ◽  
Wide Range

The complete genome sequence of soybean allows an unprecedented opportunity for the discovery of the genes controlling important traits. In particular, the potential functions of regulatory genes are a priority for analysis. The basic helix-loop-helix (bHLH) family of transcription factors is known to be involved in controlling a wide range of systems critical for crop adaptation and quality, including photosynthesis, light signalling, pigment biosynthesis, and seed pod development. Using a hidden Markov model search algorithm, 319 genes with basic helix-loop-helix transcription factor domains were identified within the soybean genome sequence. These were classified with respect to their predicted DNA binding potential, intron/exon structure, and the phylogeny of the bHLH domain. Evidence is presented that the vast majority (281) of these 319 soybean bHLH genes are expressed at the mRNA level. Of these soybean bHLH genes, 67% were found to exist in two or more homeologous copies. This dataset provides a framework for future studies on bHLH gene function in soybean. The challenge for future research remains to define functions for the bHLH factors encoded in the soybean genome, which may allow greater flexibility for genetic selection of growth and environmental adaptation in this widely grown crop.

scholarly journals Cross-Species RNAi Rescue Platform in Drosophila melanogaster

Genetics ◽  
2009 ◽  
Vol 183 (3) ◽  
pp. 1165-1173 ◽  
Author(s):  
Shu Kondo ◽  
Matthew Booker ◽  
Norbert Perrimon
Keyword(s):  
Cell Culture ◽  
Drosophila Melanogaster ◽  
Large Scale ◽  
Transgenic Animals ◽  
Selection Marker ◽  
Bacterial Artificial Chromosomes ◽  
Loss Of Function ◽  
Artificial Chromosomes ◽  
Target Effects

RNAi-mediated gene knockdown in Drosophila melanogaster is a powerful method to analyze loss-of-function phenotypes both in cell culture and in vivo. However, it has also become clear that false positives caused by off-target effects are prevalent, requiring careful validation of RNAi-induced phenotypes. The most rigorous proof that an RNAi-induced phenotype is due to loss of its intended target is to rescue the phenotype by a transgene impervious to RNAi. For large-scale validations in the mouse and Caenorhabditis elegans, this has been accomplished by using bacterial artificial chromosomes (BACs) of related species. However, in Drosophila, this approach is not feasible because transformation of large BACs is inefficient. We have therefore developed a general RNAi rescue approach for Drosophila that employs Cre/loxP-mediated recombination to rapidly retrofit existing fosmid clones into rescue constructs. Retrofitted fosmid clones carry a selection marker and a phiC31 attB site, which facilitates the production of transgenic animals. Here, we describe our approach and demonstrate proof-of-principle experiments showing that D. pseudoobscura fosmids can successfully rescue RNAi-induced phenotypes in D. melanogaster, both in cell culture and in vivo. Altogether, the tools and method that we have developed provide a gold standard for validation of Drosophila RNAi experiments.

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