Note: This page contains sample records for the topic wheat d-genome progenitor from Science.gov.
While these samples are representative of the content of Science.gov,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of Science.gov
to obtain the most current and comprehensive results.
Last update: November 12, 2013.
1

A high-density genetic linkage map of Aegilops tauschii, the D-genome progenitor of bread wheat  

Microsoft Academic Search

Aegilops tauschii is the diploid D-genome progenitor of bread wheat (Triticum aestivum L. em Thell, 2n=6x=42, AABBDD). A genetic linkage map of the Ae. tauschii genome was constructed, composed of 546 loci. One hundred and thirty two loci (24%) gave distorted segregation ratios. Sixty\\u000a nine probes (13%) detected multiple copies in the genome. One hundred and twenty three of the

E. V. Boyko; K. S. Gill; L. Mickelson-Young; S. Nasuda; W. J. Raupp; J. N. Ziegle; S. Singh; D. S. Hassawi; A. K. Fritz; D. Namuth; N. L. V. Lapitan; B. S. Gill

1999-01-01

2

Physical mapping resources for large plant genomes: radiation hybrids for wheat D-genome progenitor Aegilops tauschii  

PubMed Central

Background Development of a high quality reference sequence is a daunting task in crops like wheat with large (~17Gb), highly repetitive (>80%) and polyploid genome. To achieve complete sequence assembly of such genomes, development of a high quality physical map is a necessary first step. However, due to the lack of recombination in certain regions of the chromosomes, genetic mapping, which uses recombination frequency to map marker loci, alone is not sufficient to develop high quality marker scaffolds for a sequence ready physical map. Radiation hybrid (RH) mapping, which uses radiation induced chromosomal breaks, has proven to be a successful approach for developing marker scaffolds for sequence assembly in animal systems. Here, the development and characterization of a RH panel for the mapping of D-genome of wheat progenitor Aegilops tauschii is reported. Results Radiation dosages of 350 and 450 Gy were optimized for seed irradiation of a synthetic hexaploid (AABBDD) wheat with the D-genome of Ae. tauschii accession AL8/78. The surviving plants after irradiation were crossed to durum wheat (AABB), to produce pentaploid RH1s (AABBD), which allows the simultaneous mapping of the whole D-genome. A panel of 1,510 RH1 plants was obtained, of which 592 plants were generated from the mature RH1 seeds, and 918 plants were rescued through embryo culture due to poor germination (<3%) of mature RH1 seeds. This panel showed a homogenous marker loss (2.1%) after screening with SSR markers uniformly covering all the D-genome chromosomes. Different marker systems mostly detected different lines with deletions. Using markers covering known distances, the mapping resolution of this RH panel was estimated to be <140kb. Analysis of only 16 RH lines carrying deletions on chromosome 2D resulted in a physical map with cM/cR ratio of 1:5.2 and 15 distinct bins. Additionally, with this small set of lines, almost all the tested ESTs could be mapped. A set of 399 most informative RH lines with an average deletion frequency of ~10% were identified for developing high density marker scaffolds of the D-genome. Conclusions The RH panel reported here is the first developed for any wild ancestor of a major cultivated plant species. The results provided insight into various aspects of RH mapping in plants, including the genetically effective cell number for wheat (for the first time) and the potential implementation of this technique in other plant species. This RH panel will be an invaluable resource for mapping gene based markers, developing a complete marker scaffold for the whole genome sequence assembly, fine mapping of markers and functional characterization of genes and gene networks present on the D-genome.

2012-01-01

3

Purification and Characterization of the Glutenin Subunits of Triticum tauschii , Progenitor of the D Genome in Hexaploid Bread Wheat  

Microsoft Academic Search

Cereal Chem. 74(2):108-114 N-terminal amino acid sequences and sodium dodecyl sulfate poly- acrylamide gel electrophoresis (SDS-PAGE) molecular weights have been determined for high-performance liquid chromatography (HPLC)- purified high molecular weight (HMW) and low molecular weight (LMW) glutenin subunits (GS) of Triticum tauschii ssp. strangulata, contributor of the D genome to hexaploid bread wheat. The use of three different extraction procedures

William H. Vensel; A. Elva Adalsteins; Donald D. Kasarda

1997-01-01

4

A 4-gigabase physical map unlocks the structure and evolution of the complex genome of Aegilops tauschii, the wheat D-genome progenitor  

PubMed Central

The current limitations in genome sequencing technology require the construction of physical maps for high-quality draft sequences of large plant genomes, such as that of Aegilops tauschii, the wheat D-genome progenitor. To construct a physical map of the Ae. tauschii genome, we fingerprinted 461,706 bacterial artificial chromosome clones, assembled contigs, designed a 10K Ae. tauschii Infinium SNP array, constructed a 7,185-marker genetic map, and anchored on the map contigs totaling 4.03 Gb. Using whole genome shotgun reads, we extended the SNP marker sequences and found 17,093 genes and gene fragments. We showed that collinearity of the Ae. tauschii genes with Brachypodium distachyon, rice, and sorghum decreased with phylogenetic distance and that structural genome evolution rates have been high across all investigated lineages in subfamily Pooideae, including that of Brachypodieae. We obtained additional information about the evolution of the seven Triticeae chromosomes from 12 ancestral chromosomes and uncovered a pattern of centromere inactivation accompanying nested chromosome insertions in grasses. We showed that the density of noncollinear genes along the Ae. tauschii chromosomes positively correlates with recombination rates, suggested a cause, and showed that new genes, exemplified by disease resistance genes, are preferentially located in high-recombination chromosome regions.

Luo, Ming-Cheng; Gu, Yong Q.; You, Frank M.; Deal, Karin R.; Ma, Yaqin; Hu, Yuqin; Huo, Naxin; Wang, Yi; Wang, Jirui; Chen, Shiyong; Jorgensen, Chad M.; Zhang, Yong; McGuire, Patrick E.; Pasternak, Shiran; Stein, Joshua C.; Ware, Doreen; Kramer, Melissa; McCombie, W. Richard; Kianian, Shahryar F.; Martis, Mihaela M.; Mayer, Klaus F. X.; Sehgal, Sunish K.; Li, Wanlong; Gill, Bikram S.; Bevan, Michael W.; Simkova, Hana; Dolezel, Jaroslav; Weining, Song; Lazo, Gerard R.; Anderson, Olin D.; Dvorak, Jan

2013-01-01

5

New Hybrids with D Genome Wheat Relatives  

PubMed Central

The cytology of nine new D genome hybrids involving Triticum syriacum, Triticum ventricosum, Triticum cyclindricum, Triticum juvenale, Triticum crassum, Triticum tauschii and Triticum aestivum is described. The calculation of numerical values of the relative affinity and the patterns of chromosome pairing indicate that the D genome in T. syriacum and T. juvenale may have been substantially modified and that of T. crassum somewhat modified from that of the diploid progenitor, T. tauschii.

Zhao, Y. H.; Kimber, G.

1984-01-01

6

New hybrids with d genome wheat relatives.  

PubMed

The cytology of nine new D genome hybrids involving Triticum syriacum, Triticum ventricosum, Triticum cyclindricum, Triticum juvenale, Triticum crassum, Triticum tauschii and Triticum aestivum is described. The calculation of numerical values of the relative affinity and the patterns of chromosome pairing indicate that the D genome in T. syriacum and T. juvenale may have been substantially modified and that of T. crassum somewhat modified from that of the diploid progenitor, T. tauschii. PMID:17246199

Zhao, Y H; Kimber, G

1984-03-01

7

Alpha-gliadin genes from the A, B, and D genomes of wheat contain different sets of celiac disease epitopes  

Microsoft Academic Search

BACKGROUND: Bread wheat (Triticum aestivum) is an important staple food. However, wheat gluten proteins cause celiac disease (CD) in 0.5 to 1% of the general population. Among these proteins, the ?-gliadins contain several peptides that are associated to the disease. RESULTS: We obtained 230 distinct ?-gliadin gene sequences from severaldiploid wheat species representing the ancestral A, B, and D genomes

Teun WJM van Herpen; Svetlana V Goryunova; Johanna van der Schoot; Makedonka Mitreva; Elma Salentijn; Oscar Vorst; Martijn F Schenk; Peter A van Veelen; Frits Koning; Loek JM van Soest; Ben Vosman; Dirk Bosch; Rob J Hamer; Luud JWJ Gilissen; Marinus JM Smulders

2006-01-01

8

Transferability of wheat microsatellites to diploid Triticeae species carrying the A, B and D genomes  

Microsoft Academic Search

Hexaploid wheat (Triticum aestivum L em Thell) is derived from a complex hybridization procedure involving three diploid species carrying the A, B and D genomes.\\u000a In this study, we evaluated the ability of microsatellite sequences from T. aestivum to be revealed on different ancestral diploid species more or less closely related, i.e. to test for their transferability.\\u000a Fifty five primer

P. Sourdille; M. Tavaud; G. Charmet; M. Bernard

2001-01-01

9

Aegilops tauschii single nucleotide polymorphisms shed light on the origins of wheat D-genome genetic diversity and pinpoint the geographic origin of hexaploid wheat.  

PubMed

Hexaploid wheat (Triticum aestivum, genomes AABBDD) originated by hybridization of tetraploid Triticum turgidum (genomes AABB) with Aegilops tauschii (genomes DD). Genetic relationships between A. tauschii and the wheat D genome are of central importance for the understanding of wheat origin and subsequent evolution. Genetic relationships among 477 A. tauschii and wheat accessions were studied with the A. tauschii 10K Infinium single nucleotide polymorphism (SNP) array. Aegilops tauschii consists of two lineages (designated 1 and 2) having little genetic contact. Each lineage consists of two closely related sublineages. A population within lineage 2 in the southwestern and southern Caspian appears to be the main source of the wheat D genome. Lineage 1 contributed as little as 0.8% of the wheat D genome. Triticum aestivum is subdivided into the western and Far Eastern populations. The Far Eastern population conserved the genetic make-up of the nascent T. aestivum more than the western population. In wheat, diversity is high in chromosomes 1D and 2D and it correlates in all wheat D-genome and A. tauschii chromosomes with recombination rates. Gene flow from A. tauschii was an important source of wheat genetic diversity and shaped its distribution along the D-genome chromosomes. PMID:23374069

Wang, Jirui; Luo, Ming-Cheng; Chen, Zhongxu; You, Frank M; Wei, Yuming; Zheng, Youliang; Dvorak, Jan

2013-02-04

10

Draft genome of the wheat A-genome progenitor Triticum urartu.  

PubMed

Bread wheat (Triticum aestivum, AABBDD) is one of the most widely cultivated and consumed food crops in the world. However, the complex polyploid nature of its genome makes genetic and functional analyses extremely challenging. The A?genome, as a basic genome of bread wheat and other polyploid wheats, for example, T. turgidum (AABB), T. timopheevii (AAGG) and T. zhukovskyi (AAGGA(m)A(m)), is central to wheat evolution, domestication and genetic improvement. The progenitor species of the A?genome is the diploid wild einkorn wheat T.?urartu, which resembles cultivated wheat more extensively than do Aegilops speltoides (the ancestor of the B genome) and Ae. tauschii (the donor of the D genome), especially in the morphology and development of spike and seed. Here we present the generation, assembly and analysis of a whole-genome shotgun draft sequence of the T.?urartu genome. We identified protein-coding gene models, performed genome structure analyses and assessed its utility for analysing agronomically important genes and for developing molecular markers. Our T.?urartu genome assembly provides a diploid reference for analysis of polyploid wheat genomes and is a valuable resource for the genetic improvement of wheat. PMID:23535596

Ling, Hong-Qing; Zhao, Shancen; Liu, Dongcheng; Wang, Junyi; Sun, Hua; Zhang, Chi; Fan, Huajie; Li, Dong; Dong, Lingli; Tao, Yong; Gao, Chuan; Wu, Huilan; Li, Yiwen; Cui, Yan; Guo, Xiaosen; Zheng, Shusong; Wang, Biao; Yu, Kang; Liang, Qinsi; Yang, Wenlong; Lou, Xueyuan; Chen, Jie; Feng, Mingji; Jian, Jianbo; Zhang, Xiaofei; Luo, Guangbin; Jiang, Ying; Liu, Junjie; Wang, Zhaobao; Sha, Yuhui; Zhang, Bairu; Wu, Huajun; Tang, Dingzhong; Shen, Qianhua; Xue, Pengya; Zou, Shenhao; Wang, Xiujie; Liu, Xin; Wang, Famin; Yang, Yanping; An, Xueli; Dong, Zhenying; Zhang, Kunpu; Zhang, Xiangqi; Luo, Ming-Cheng; Dvorak, Jan; Tong, Yiping; Wang, Jian; Yang, Huanming; Li, Zhensheng; Wang, Daowen; Zhang, Aimin; Wang, Jun

2013-03-24

11

Variation in abscisic acid responsiveness of Aegilops tauschii and hexaploid wheat synthetics due to the D-genome diversity.  

PubMed

Common wheat (Triticum aestivum L.) is an allohexaploid that originated from natural hybridization between tetraploid wheat (Triticum turgidum) and diploid Aegilops tauschii. Ae. tauschii is considered one of the potential sources of new genetic variation in abiotic stress tolerance for improving common wheat. Abscisic acid (ABA) plays an important role in plant adaptation to environmental stresses. In this study, ABA responsiveness of 67 Ae. tauschii accessions and their synthetic hexaploid wheat lines, derived from crosses between T. turgidum cv. Langdon and the Ae. tauschii accessions, was evaluated based on growth inhibition by 20 µM ABA. Wide variation was found in ABA responsiveness for both synthetic wheat lines and their parental Ae. tauschii accessions. The variations due to D-genome found at the diploid level were also expressed in a hexaploid genetic background. Two pairs of synthetic wheat lines differing in ABA responsiveness were then selected for gene expression analysis and to test abiotic stress tolerance, because their parental Ae. tauschii accessions similarly exhibited the differential response to ABA. Gene expression of ABA inducible transcription factor, WABI5, and the downstream Cor/Lea genes (Wrab17, Wdhn13 and Wrab18) were analysed. In one pair, the highly responsive line exhibited higher induction of Wrab17 by ABA treatment, but no significant difference in dehydration or salinity tolerance was observed between these lines. In contrast, in the second pair, the highly ABA-responsive line showed higher levels of Wdhn13 expression and dehydration and salinity tolerance. In synthetic wheat lines, the difference in the ABA responsiveness of the lines appeared to be determined by the different sets of D-genome genes. Our findings suggest that highly ABA-responsive Ae. tauschii accessions should be valuable genetic resources for improving the abiotic stress tolerance of common wheat. PMID:22531790

Iehisa, Julio C M; Takumi, Shigeo

2012-01-01

12

Cbf14 copy number variation in the A, B, and D genomes of diploid and polyploid wheat.  

PubMed

Freezing tolerance and winter hardiness are complex traits. In the Triticeae, two loci on the group 5 chromosome homoeologs are repeatedly identified as having major effects on these traits. Recently, we found that segments of the genomic region at one of these loci, Frost resistance-2 (Fr-2) is copy number variable in barley. Freezing-tolerant winter-hardy genotypes have greater tandem copy numbers of the genomic region encompassing the C-repeat binding factor genes Cbf2A and Cbf4B at Fr-H2 than the less freezing-tolerant nonwinter-hardy genotypes. Here we report that in wheat the Cbf14 gene at Fr-2 is copy number variable. Using DNA blot hybridizations, we estimated copy numbers of Cbf14 across the different genomes of diploid and polyploid wheat. Copy numbers of Cbf14 are lower in the B genome than in the A and D genomes across all ploidy levels. Among hexaploid red wheats, winter genotypes harbor greater Cbf14 copy numbers than spring genotypes. Cbf14 copy numbers also vary across the red winter wheats such that hard wheats harbor greater copy numbers than soft wheats. Analysis of hexaploid wheat chromosome 5 substitution lines indicates that Cbf14 copy numbers in the introgressions are stable in the different backgrounds. Taken together our data suggest that higher copy number states existed in the diploid wild ancestors prior to the polyploidization events and that the loss of Cbf14 copies occurred in the cultivated germplasm. PMID:23918064

Dhillon, Taniya; Stockinger, Eric J

2013-08-06

13

Identification of a complete set of isogenic wheat\\/rye D-genome substitution lines by means of Giemsa C-banding  

Microsoft Academic Search

A complete set of isogenic wheat\\/rye D-genome substitutions were produced by crossing an inbred line of spring rye Secale cereale L. cv. “Prolific” to a tetraploid wheat, the A-and B-genomes of which had previously been extracted from hexaploid wheat, Triticum aestivum L. em Thell. cv. “Thatcher”. After chromosome doubling, the derived hexaploid triticale (x Triticosecale Wittmack) was backcrossed to 6x

B. Friebe; E. N. Larter

1988-01-01

14

Endosperm Tolerance of Paternal Aneuploidy Allows Radiation Hybrid Mapping of the Wheat D-Genome and a Measure of ? Ray-Induced Chromosome Breaks  

PubMed Central

Physical mapping and genome sequencing are underway for the ?17 Gb wheat genome. Physical mapping methods independent of meiotic recombination, such as radiation hybrid (RH) mapping, will aid precise anchoring of BAC contigs in the large regions of suppressed recombination in Triticeae genomes. Reports of endosperm development following pollination with irradiated pollen at dosages that cause embryo abortion prompted us to investigate endosperm as a potential source of RH mapping germplasm. Here, we report a novel approach to construct RH based physical maps of all seven D-genome chromosomes of the hexaploid wheat ‘Chinese Spring’, simultaneously. An 81-member subset of endosperm samples derived from 20-Gy irradiated pollen was genotyped for deletions, and 737 markers were mapped on seven D-genome chromosomes. Analysis of well-defined regions of six chromosomes suggested a map resolution of ?830 kb could be achieved; this estimate was validated with assays of markers from a sequenced contig. We estimate that the panel contains ?6,000 deletion bins for D-genome chromosomes and will require ?18,000 markers for high resolution mapping. Map-based deletion estimates revealed a majority of 1–20 Mb interstitial deletions suggesting mutagenic repair of double-strand breaks in pollen provides a useful resource for RH mapping and map based cloning studies.

Tiwari, Vijay K.; Riera-Lizarazu, Oscar; Gunn, Hilary L.; Lopez, KaSandra; Iqbal, M. Javed; Kianian, Shahryar F.; Leonard, Jeffrey M.

2012-01-01

15

Intraspecific sequence comparisons reveal similar rates of non-collinear gene insertion in the B and D genomes of bread wheat  

PubMed Central

Background Polyploidization is considered one of the main mechanisms of plant genome evolution. The presence of multiple copies of the same gene reduces selection pressure and permits sub-functionalization and neo-functionalization leading to plant diversification, adaptation and speciation. In bread wheat, polyploidization and the prevalence of transposable elements resulted in massive gene duplication and movement. As a result, the number of genes which are non-collinear to genomes of related species seems markedly increased in wheat. Results We used new-generation sequencing (NGS) to generate sequence of a Mb-sized region from wheat chromosome arm 3DS. Sequence assembly of 24 BAC clones resulted in two scaffolds of 1,264,820 and 333,768 bases. The sequence was annotated and compared to the homoeologous region on wheat chromosome 3B and orthologous loci of Brachypodium distachyon and rice. Among 39 coding sequences in the 3DS scaffolds, 32 have a homoeolog on chromosome 3B. In contrast, only fifteen and fourteen orthologs were identified in the corresponding regions in rice and Brachypodium, respectively. Interestingly, five pseudogenes were identified among the non-collinear coding sequences at the 3B locus, while none was found at the 3DS locus. Conclusion Direct comparison of two Mb-sized regions of the B and D genomes of bread wheat revealed similar rates of non-collinear gene insertion in both genomes with a majority of gene duplications occurring before their divergence. Relatively low proportion of pseudogenes was identified among non-collinear coding sequences. Our data suggest that the pseudogenes did not originate from insertion of non-functional copies, but were formed later during the evolution of hexaploid wheat. Some evidence was found for gene erosion along the B genome locus.

2012-01-01

16

Stably Expressed D Genome-derived HMW Glutenin Subunit Genes Transformed Into Different Durum Wheat Genotypes Change Dough Mixing Properties  

Technology Transfer Automated Retrieval System (TEKTRAN)

The glutenin subunits 1Dx5 and 1Dy10 are encoded by chromosome 1D and associated with higher dough strength in hexaploid bread wheats. In order to study the effects of their expression in different durum wheat genotypes, four cultivars commonly grown in the Mediterranean area were co-transformed, vi...

17

PCR-based landmark unique gene (PLUG) markers effectively assign homoeologous wheat genes to A, B and D genomes  

PubMed Central

Background EST-PCR markers normally represent specific products from target genes, and are therefore effective tools for genetic analysis. However, because wheat is an allohexaploid plant, PCR products derived from homoeologous genes are often simultaneously amplified. Such products may be easier to differentiate if they include intron sequences, which are more polymorphic than exon sequences. However, genomic sequence data for wheat are limited; therefore it is difficult to predict the location of introns. By using the similarities in gene structures between rice and wheat, we developed a system called PLUG (PCR-based Landmark Unique Gene) to design primers so that PCR products include intron sequences. We then investigated whether products amplified using such primers could serve as markers able to distinguish multiple products derived from homoeologous genes. Results The PLUG system consists of the following steps: (1) Single-copy rice genes (Landmark Unique Gene loci; LUGs) exhibiting high degrees of homology to wheat UniGene sequences are extracted; (2) Alignment analysis is carried out using the LUGs and wheat UniGene sequences to predict exon-exon junctions, and LUGs which can be used to design wheat primers flanking introns (TaEST-LUGs) are extracted; and (3) Primers are designed in an interactive manner. From a total of 4,312 TaEST-LUGs, 24 loci were randomly selected and used to design primers. With all of these primer sets, we obtained specific, intron-containing products from the target genes. These markers were assigned to chromosomes using wheat nullisomic-tetrasomic lines. By PCR-RFLP analysis using agarose gel electrophoresis, 19 of the 24 markers were located on at least one chromosome. Conclusion In the development of wheat EST-PCR markers capable of efficiently sorting products derived from homoeologous genes, it is important to design primers able to amplify products that include intron sequences with insertion/deletion polymorphisms. Using the PLUG system, wheat EST sequences that can be used for marker development are selected based on comparative genomics with rice, and then primer sets flanking intron sequences are prepared in an interactive, semi-automatic manner. Hence, the PLUG system is an effective tool for large-scale marker development.

Ishikawa, Goro; Yonemaru, Junichi; Saito, Mika; Nakamura, Toshiki

2007-01-01

18

Genetic map of Triticum turgidum based on a hexaploid wheat population without genetic recombination for D genome  

PubMed Central

Background A synthetic doubled-haploid hexaploid wheat population, SynDH1, derived from the spontaneous chromosome doubling of triploid F1 hybrid plants obtained from the cross of hybrids Triticum turgidum ssp. durum line Langdon (LDN) and ssp. turgidum line AS313, with Aegilops tauschii ssp. tauschii accession AS60, was previously constructed. SynDH1 is a tetraploidization-hexaploid doubled haploid (DH) population because it contains recombinant A and B chromosomes from two different T. turgidum genotypes, while all the D chromosomes from Ae. tauschii are homogenous across the whole population. This paper reports the construction of a genetic map using this population. Results Of the 606 markers used to assemble the genetic map, 588 (97%) were assigned to linkage groups. These included 513 Diversity Arrays Technology (DArT) markers, 72 simple sequence repeat (SSR), one insertion site-based polymorphism (ISBP), and two high-molecular-weight glutenin subunit (HMW-GS) markers. These markers were assigned to the 14 chromosomes, covering 2048.79?cM, with a mean distance of 3.48?cM between adjacent markers. This map showed good coverage of the A and B genome chromosomes, apart from 3A, 5A, 6A, and 4B. Compared with previously reported maps, most shared markers showed highly consistent orders. This map was successfully used to identify five quantitative trait loci (QTL), including two for spikelet number on chromosomes 7A and 5B, two for spike length on 7A and 3B, and one for 1000-grain weight on 4B. However, differences in crossability QTL between the two T. turgidum parents may explain the segregation distortion regions on chromosomes 1A, 3B, and 6B. Conclusions A genetic map of T. turgidum including 588 markers was constructed using a synthetic doubled haploid (SynDH) hexaploid wheat population. Five QTLs for three agronomic traits were identified from this population. However, more markers are needed to increase the density and resolution of this map in the future study.

2012-01-01

19

Discovery of High-Confidence Single Nucleotide Polymorphisms from Large-Scale De Novo Analysis of Leaf Transcripts of Aegilops tauschii, A Wild Wheat Progenitor  

PubMed Central

Construction of high-resolution genetic maps is important for genetic and genomic research, as well as for molecular breeding. Single nucleotide polymorphisms (SNPs) are the predominant class of genetic variation and can be used as molecular markers. Aegilops tauschii, the D-genome donor of common wheat, is considered a valuable genetic resource for wheat improvement. Our previous study implied that Ae. tauschii accessions can be genealogically divided into two major lineages. In this study, the transcriptome of two Ae. tauschii accessions from each lineage, lineage 1 (L1) and 2 (L2), was sequenced, yielding 9435 SNPs and 739 insertion/deletion polymorphisms (indels) after de novo assembly of the reads. Based on 36 contig sequences, 31 SNPs and six indels were validated on 20 diverse Ae. tauschii accessions. Because almost all of the SNP markers were polymorphic between L1 and L2, and the D-genome donor of common wheat is presumed to belong to L2, these markers are available for D-genome typing in crosses between common wheat varieties and L1-derived synthetic wheat. Due to the conserved synteny between wheat and barley chromosomes, the high-density expressed sequence tag barley map and the hypothetical gene order in barley can be applied to develop markers on target chromosomal regions in wheat.

Iehisa, Julio Cesar Masaru; Shimizu, Akifumi; Sato, Kazuhiro; Nasuda, Shuhei; Takumi, Shigeo

2012-01-01

20

Effects of NaCl on protein profiles of tetraploid and hexaploid wheat species and their diploid wild progenitors  

Microsoft Academic Search

The soluble proteins extracted from the first leaf tissues of cultivated tetraploid ( Triticum durum Desf., genome AB) and hexaploid (T. aestivum L., genome ABD) wheat species and their diploid wild progenitors (T. monococ- cum L. (A), Aegilops speltoides Tausch (B), and Aegilops tauschii Cosson ( D)) exposed to 100 mmol\\/l NaCl stress were separated by two-dimensional (2D) gel electrophoresis.

M. Yildiz; H. Terzi

2008-01-01

21

Genome-wide gene expression changes in genetically stable synthetic and natural wheat allohexaploids.  

PubMed

*The present study aims to understand regulation of gene expression in synthetic and natural wheat (Triticum aestivum) allohexaploids, that combines the AB genome of Triticum turgidum and the D genome of Aegilops tauschii; and which we have recently characterized as genetically stable. *We conducted a comprehensive genome-wide analysis of gene expression that allowed characterization of the effect of variability of the D genome progenitor, the intergenerational stability as well as the comparison with natural wheat allohexaploid. We used the Affymetrix GeneChip Wheat Genome Array, on which 55 049 transcripts are represented. *Additive expression was shown to represent the majority of expression regulation in the synthetic allohexaploids, where expression for more than c. 93% of transcripts was equal to the mid-parent value measured from a mixture of parental RNA. This leaves c. 2000 (c. 7%) transcripts, in which expression was nonadditive. No global gene expression bias or dominance towards any of the progenitor genomes was observed whereas high intergenerational stability and low effect of the D genome progenitor variability were revealed. *Our study suggests that gene expression regulation in wheat allohexaploids is established early upon allohexaploidization and highly conserved over generations, as demonstrated by the high similarity of expression with natural wheat allohexaploids. PMID:20591055

Chagué, Véronique; Just, Jérémy; Mestiri, Imen; Balzergue, Sandrine; Tanguy, Anne-Marie; Huneau, Cecile; Huteau, Virginie; Belcram, Harry; Coriton, Olivier; Jahier, Joseph; Chalhoub, Boulos

2010-06-25

22

Genome Variation Within Triticale in Comparison to its Wheat and Rye Progenitors  

Technology Transfer Automated Retrieval System (TEKTRAN)

Genome variation in the intergeneric wheat-rye hybrid triticale (X Triticosecale Wittmack) has been a puzzle to scientists and plant breeders since the first triticale was synthesized. The existence of unexplained genetic variation in triticale as compared to the parents has been a hindrance to bre...

23

Detection of single nucleotide polymorphisms in 24 kDa dimeric ?-amylase inhibitors from cultivated wheat and its diploid putative progenitors  

Microsoft Academic Search

Seventeen new genes encoding 24 kDa family dimeric ?-amylase inhibitors had been characterized from cultivated wheat and its diploid putative progenitors. And the different ?-amylase inhibitors in this family, which were determined by coding regions single nucleotide polymorphisms (cSNPs) of their genes, were investigated. The amino acid sequences of 24 kDa ?-amylase inhibitors shared very high coherence (91.2%). It indicated

Ji-Rui Wang; Yu-Ming Wei; Ze-Hong Yan; You-Liang Zheng

2005-01-01

24

Prevalence of gene expression additivity in genetically stable wheat allohexaploids.  

PubMed

The reprogramming of gene expression appears as the major trend in synthetic and natural allopolyploids where expression of an important proportion of genes was shown to deviate from that of the parents or the average of the parents. In this study, we analyzed gene expression changes in previously reported, highly stable synthetic wheat allohexaploids that combine the D genome of Aegilops tauschii and the AB genome extracted from the natural hexaploid wheat Triticum aestivum. A comprehensive genome-wide analysis of transcriptional changes using the Affymetrix GeneChip Wheat Genome Array was conducted. Prevalence of gene expression additivity was observed where expression does not deviate from the average of the parents for 99.3% of 34,820 expressed transcripts. Moreover, nearly similar expression was observed (for 99.5% of genes) when comparing these synthetic and natural wheat allohexaploids. Such near-complete additivity has never been reported for other allopolyploids and, more interestingly, for other synthetic wheat allohexaploids that differ from the ones studied here by having the natural tetraploid Triticum turgidum as the AB genome progenitor. Our study gave insights into the dynamics of additive gene expression in the highly stable wheat allohexaploids. PMID:23278496

Chelaifa, Houda; Chagué, Véronique; Chalabi, Smahane; Mestiri, Imen; Arnaud, Dominique; Deffains, Denise; Lu, Yunhai; Belcram, Harry; Huteau, Virginie; Chiquet, Julien; Coriton, Olivier; Just, Jérémy; Jahier, Joseph; Chalhoub, Boulos

2012-12-21

25

Effect of genome and ploidy on photosynthesis of wheat  

Microsoft Academic Search

We assessed (1) the effects of addition and doses of the D genome from different sources and (2) the addition of either the\\u000a A genome or the D genome on the photosynthesis of synthesized hexaploid wheats. On average, the increased doses of the D genome\\u000a reduced photosynthesis, but the depression was dependent on the source of the D genome. Two

N. Watanabe; S. Kobayashi; Y. Furuta

1997-01-01

26

Duplication and partitioning in evolution and function of homoeologous Q loci governing domestication characters in polyploid wheat  

PubMed Central

The Q gene encodes an AP2-like transcription factor that played an important role in domestication of polyploid wheat. The chromosome 5A Q alleles (5AQ and 5Aq) have been well studied, but much less is known about the q alleles on wheat homoeologous chromosomes 5B (5Bq) and 5D (5Dq). We investigated the organization, evolution, and function of the Q/q homoeoalleles in hexaploid wheat (Triticum aestivum L.). Q/q gene sequences are highly conserved within and among the A, B, and D genomes of hexaploid wheat, the A and B genomes of tetraploid wheat, and the A, S, and D genomes of the diploid progenitors, but the intergenic regions of the Q/q locus are highly divergent among homoeologous genomes. Duplication of the q gene 5.8 Mya was likely followed by selective loss of one of the copies from the A genome progenitor and the other copy from the B, D, and S genomes. A recent V329-to-I mutation in the A lineage is correlated with the Q phenotype. The 5Bq homoeoalleles became a pseudogene after allotetraploidization. Expression analysis indicated that the homoeoalleles are coregulated in a complex manner. Combined phenotypic and expression analysis indicated that, whereas 5AQ plays a major role in conferring domestication-related traits, 5Dq contributes directly and 5Bq indirectly to suppression of the speltoid phenotype. The evolution of the Q/q loci in polyploid wheat resulted in the hyperfunctionalization of 5AQ, pseudogenization of 5Bq, and subfunctionalization of 5Dq, all contributing to the domestication traits.

Zhang, Zengcui; Belcram, Harry; Gornicki, Piotr; Charles, Mathieu; Just, Jeremy; Huneau, Cecile; Magdelenat, Ghislaine; Couloux, Arnaud; Samain, Sylvie; Gill, Bikram S.; Rasmussen, Jack B.; Barbe, Valerie; Faris, Justin D.; Chalhoub, Boulos

2011-01-01

27

Genes encoding plastid acetyl-CoA carboxylase and 3-phosphoglycerate kinase of the Triticum/Aegilops complex and the evolutionary history of polyploid wheat.  

PubMed

The classic wheat evolutionary history is one of adaptive radiation of the diploid Triticum/Aegilops species (A, S, D), genome convergence and divergence of the tetraploid (Triticum turgidum AABB, and Triticum timopheevii AAGG) and hexaploid (Triticum aestivum, AABBDD) species. We analyzed Acc-1 (plastid acetyl-CoA carboxylase) and Pgk-1 (plastid 3-phosphoglycerate kinase) genes to determine phylogenetic relationships among Triticum and Aegilops species of the wheat lineage and to establish the timeline of wheat evolution based on gene sequence comparisons. Triticum urartu was confirmed as the A genome donor of tetraploid and hexaploid wheat. The A genome of polyploid wheat diverged from T. urartu less than half a million years ago (MYA), indicating a relatively recent origin of polyploid wheat. The D genome sequences of T. aestivum and Aegilops tauschii are identical, confirming that T. aestivum arose from hybridization of T. turgidum and Ae. tauschii only 8,000 years ago. The diploid Triticum and Aegilops progenitors of the A, B, D, G, and S genomes all radiated 2.5-4.5 MYA. Our data suggest that the Acc-1 and Pgk-1 loci have different histories in different lineages, indicating genome mosaicity and significant intraspecific differentiation. Some loci of the S genome of Aegilops speltoides and the G genome of T. timophevii are closely related, suggesting the same origin of some parts of their genomes. None of the Aegilops genomes analyzed is a close relative of the B genome, so the diploid progenitor of the B genome remains unknown. PMID:12060759

Huang, Shaoxing; Sirikhachornkit, Anchalee; Su, Xiujuan; Faris, Justin; Gill, Bikram; Haselkorn, Robert; Gornicki, Piotr

2002-06-11

28

Analysis of the bread wheat genome using whole genome shotgun sequencing  

PubMed Central

Summary Bread wheat (Triticum aestivum) is a globally important crop, accounting for 20% of the calories consumed by mankind. We sequenced its large and challenging 17 Gb hexaploid genome using 454 pyrosequencing and compared this with the sequences of diploid ancestral and progenitor genomes. Between 94,000-96,000 genes were identified, and two-thirds were assigned to the A, B and D genomes. High-resolution synteny maps identified many small disruptions to conserved gene order. We show the hexaploid genome is highly dynamic, with significant loss of gene family members upon polyploidization and domestication, and an abundance of gene fragments. Several classes of genes involved in energy harvesting, metabolism and growth are among expanded gene families that could be associated with crop productivity. Our analyses, coupled with the identification of extensive genetic variation, provide a new resource for accelerating gene discovery and improving this major crop.

Brenchley, Rachel; Spannagl, Manuel; Pfeifer, Matthias; Barker, Gary L.A.; D'Amore, Rosalinda; Allen, Alexandra M.; McKenzie, Neil; Kramer, Melissa; Kerhornou, Arnaud; Bolser, Dan; Kay, Suzanne; Waite, Darren; Trick, Martin; Bancroft, Ian; Gu, Yong; Huo, Naxin; Luo, Ming-Cheng; Sehgal, Sunish; Kianian, Sharyar; Gill, Bikram; Anderson, Olin; Kersey, Paul; Dvorak, Jan; McCombie, Richard; Hall, Anthony; Mayer, Klaus F.X.; Edwards, Keith J.; Bevan, Michael W.; Hall, Neil

2012-01-01

29

Introgression of stem rust resistance genes SrTA10187 and SrTA10171 from Aegilops tauschii to wheat.  

PubMed

Aegilops tauschii, the diploid progenitor of the wheat D genome, is a readily accessible germplasm pool for wheat breeding as genes can be transferred to elite wheat cultivars through direct hybridization followed by backcrossing. Gene transfer and genetic mapping can be integrated by developing mapping populations during backcrossing. Using direct crossing, two genes for resistance to the African stem rust fungus race TTKSK (Ug99), were transferred from the Ae. tauschii accessions TA10187 and TA10171 to an elite hard winter wheat line, KS05HW14. BC2 mapping populations were created concurrently with developing advanced backcross lines carrying rust resistance. Bulked segregant analysis on the BC2 populations identified marker loci on 6DS and 7DS linked to stem rust resistance genes transferred from TA10187 and TA10171, respectively. Linkage maps were developed for both genes and closely linked markers reported in this study will be useful for selection and pyramiding with other Ug99-effective stem rust resistance genes. The Ae. tauschii-derived resistance genes were temporarily designated SrTA10187 and SrTA10171 and will serve as valuable resources for stem rust resistance breeding. PMID:23864229

Olson, Eric L; Rouse, Matthew N; Pumphrey, Michael O; Bowden, Robert L; Gill, Bikram S; Poland, Jesse A

2013-07-18

30

Acc homoeoloci and the evolution of wheat genomes  

Microsoft Academic Search

The DNA sequences of wheat Acc-1 and Acc-2 loci, encoding the plastid and cytosolic forms of the enzyme acetyl-CoA carboxylase, were analyzed with a view to understanding the evolution of these genes and the origin of the three genomes in modern hexaploid wheat. Acc-1 and Acc-2 loci from each of the wheats Triticum urartu (A genome), Aegilops tauschii (D genome),

D. Chalupska; H. Y. Lee; J. D. Faris; A. Evrard; B. Chalhoub; R. Haselkorn; P. Gornicki

2008-01-01

31

Coverage and Consistency: Bioinformatics Aspects of the Analysis of Multirun iTRAQ Experiments with Wheat Leaves.  

PubMed

The hexaploid genome of bread wheat (Triticum aestivum) is large (17 Gb) and repetitive, and this has delayed full sequencing and annotation of the genome, which is a prerequisite for effective quantitative proteomics analysis. Aware of these constraints we investigated the most effective approaches for shotgun proteomic analyses of bread wheat that would support large-scale quantitative comparisons using iTRAQ reagents. We used a data set that was generated by two-dimensional LC-MS of iTRAQ labeled peptides from wheat leaves. The main items considered in this study were the choice of sequence database for matching LC-MS data, the consistency of identification when multiple LC-MS runs were acquired, and the options for downstream functional analysis to generate useful insight. For peptide identification we examined the extensive NCBInr plant database, a smaller composite cereals database, the Brachypodium distachyon model plant genome, the EST-based SuperWheat database, as well as the genome sequence from the recently sequenced D-genome progenitor Aegilops tauschii. While the most spectra were assigned by using the SuperWheat database, this extremely large database could not be readily manipulated for the robust protein grouping that is required for large-scale, multirun quantitative experiments. We demonstrated a pragmatic alternative of using the composite cereals database for peptide spectra matching. The stochastic aspect of protein grouping across LC-MS runs was investigated using the smaller composite cereals database where we found that attaching the Brachypodium best BLAST hit reduced this problem. Further, assigning quantitation to the best Brachypodium locus yielded promising results enabling integration with existing downstream data mining and functional analysis tools. Our study demonstrated viable approaches for quantitative proteomics analysis of bread wheat samples and shows how these approaches could be similarly adopted for analysis of other organisms with unsequenced or incompletely sequenced genomes. PMID:24015675

Pascovici, Dana; Gardiner, Donald M; Song, Xiaomin; Breen, Edmond; Solomon, Peter S; Keighley, Tim; Molloy, Mark P

2013-09-20

32

Identification and mapping of QTLs for FHB resistance in a synthetic hexaploid wheat line  

Technology Transfer Automated Retrieval System (TEKTRAN)

The synthetic hexaploid wheat (SHW) lines derived from crosses between tetraploid wheat (AABB genome) and Aegilops tauschii (D genome) possess resistance to various diseases including Fusarium head blight (FHB). However, the genetics of FHB resistance in these synthetic lines is poorly understood. B...

33

Genetic diversity in conventional and synthetic wheats with drought and salinity tolerance based on AFLP  

Technology Transfer Automated Retrieval System (TEKTRAN)

Genetic diversity, among fourteen drought and twenty-seven salinity tolerant conventional and synthetic wheat (Triticum sp.) accessions containing different sources of the D genome, was assessed using amplified fragment length polymorphism (AFLP). The wheat accessions were analyzed with 20 EcoRI/Mse...

34

Two Homoeologous Wheat Genes Confer Sensitivity to a Single Host-Selective Toxin and Susceptibility to Stagonospora nodorum blotch (SNB)  

Technology Transfer Automated Retrieval System (TEKTRAN)

The pathogen Stagonospora nodorum produces multiple host-selective toxins that interact with corresponding wheat sensitivity genes in an inverse gene-for-gene manner to cause the disease Stagonospora nodorum blotch (SNB) in wheat. Here, we screened accessions of Aegilops tauschii, the D-genome donor...

35

SYNTENY PERTURBATIONS BETWEEN WHEAT HOMOEOLOGOUS CHROMOSOMES CAUSED BY LOCUS DUPLICATIONS AND DELETIONS CORRELATE WITH RECOMBINATION RATES ALONG CHROMOSOME ARMS  

Technology Transfer Automated Retrieval System (TEKTRAN)

A database of close to 10,000 wheat loci detected by 3977 expressed sequence tag (EST) unigenes and mapped into 159 bins delineated by breakpoints of a series of overlapping deletions was used to assess synteny along homoeologous chromosomes of the wheat A, B, and D genomes in relation to bin positi...

36

Wheat Allergy  

MedlinePLUS

... years. Most children with wheat allergy have other food allergies. Children usually outgrow wheat allergy between ages 3 and ... Hand Scheduled Section Focus Related Links Related Guides Children Parent Food allergy References Inomata N. Wheat allergy. Current Opinion ...

37

The impact of Ty3-gypsy group LTR retrotransposons Fatima on B-genome specificity of polyploid wheats  

PubMed Central

Background Transposable elements (TEs) are a rapidly evolving fraction of the eukaryotic genomes and the main contributors to genome plasticity and divergence. Recently, occupation of the A- and D-genomes of allopolyploid wheat by specific TE families was demonstrated. Here, we investigated the impact of the well-represented family of gypsy LTR-retrotransposons, Fatima, on B-genome divergence of allopolyploid wheat using the fluorescent in situ hybridisation (FISH) method and phylogenetic analysis. Results FISH analysis of a BAC clone (BAC_2383A24) initially screened with Spelt1 repeats demonstrated its predominant localisation to chromosomes of the B-genome and its putative diploid progenitor Aegilops speltoides in hexaploid (genomic formula, BBAADD) and tetraploid (genomic formula, BBAA) wheats as well as their diploid progenitors. Analysis of the complete BAC_2383A24 nucleotide sequence (113 605 bp) demonstrated that it contains 55.6% TEs, 0.9% subtelomeric tandem repeats (Spelt1), and five genes. LTR retrotransposons are predominant, representing 50.7% of the total nucleotide sequence. Three elements of the gypsy LTR retrotransposon family Fatima make up 47.2% of all the LTR retrotransposons in this BAC. In situ hybridisation of the Fatima_2383A24-3 subclone suggests that individual representatives of the Fatima family contribute to the majority of the B-genome specific FISH pattern for BAC_2383A24. Phylogenetic analysis of various Fatima elements available from databases in combination with the data on their insertion dates demonstrated that the Fatima elements fall into several groups. One of these groups, containing Fatima_2383A24-3, is more specific to the B-genome and proliferated around 0.5-2.5 MYA, prior to allopolyploid wheat formation. Conclusion The B-genome specificity of the gypsy-like Fatima, as determined by FISH, is explained to a great degree by the appearance of a genome-specific element within this family for Ae. speltoides. Moreover, its proliferation mainly occurred in this diploid species before it entered into allopolyploidy. Most likely, this scenario of emergence and proliferation of the genome-specific variants of retroelements, mainly in the diploid species, is characteristic of the evolution of all three genomes of hexaploid wheat.

2011-01-01

38

A New Class of Wheat Gliadin Genes and Proteins  

PubMed Central

The utility of mining DNA sequence data to understand the structure and expression of cereal prolamin genes is demonstrated by the identification of a new class of wheat prolamins. This previously unrecognized wheat prolamin class, given the name ?-gliadins, is the most direct ortholog of barley ?3-hordeins. Phylogenetic analysis shows that the orthologous ?-gliadins and ?3-hordeins form a distinct prolamin branch that existed separate from the ?-gliadins and ?-hordeins in an ancestral Triticeae prior to the branching of wheat and barley. The expressed ?-gliadins are encoded by a single gene in each of the hexaploid wheat genomes. This single ?-gliadin/?3-hordein ortholog may be a general feature of the Triticeae tribe since examination of ESTs from three barley cultivars also confirms a single ?3-hordein gene. Analysis of ESTs and cDNAs shows that the genes are expressed in at least five hexaploid wheat cultivars in addition to diploids Triticum monococcum and Aegilops tauschii. The latter two sequences also allow assignment of the ?-gliadin genes to the A and D genomes, respectively, with the third sequence type assumed to be from the B genome. Two wheat cultivars for which there are sufficient ESTs show different patterns of expression, i.e., with cv Chinese Spring expressing the genes from the A and B genomes, while cv Recital has ESTs from the A and D genomes. Genomic sequences of Chinese Spring show that the D genome gene is inactivated by tandem premature stop codons. A fourth ?-gliadin sequence occurs in the D genome of both Chinese Spring and Ae. tauschii, but no ESTs match this sequence and limited genomic sequences indicates a pseudogene containing frame shifts and premature stop codons. Sequencing of BACs covering a 3 Mb region from Ae. tauschii locates the ?-gliadin gene to the complex Gli-1 plus Glu-3 region on chromosome 1.

Anderson, Olin D.; Dong, Lingli; Huo, Naxin; Gu, Yong Q.

2012-01-01

39

A reconsideration of the domestication geography of tetraploid wheats  

Microsoft Academic Search

The domestication of tetraploid wheats started from their wild progenitor Triticum dicoccoides. In this paper, the geographical distribution of this progenitor is revised to include more sampling locations. The paper is based on a collection of wild and domesticated lines (226 accessions in total) analyzed by AFLP at 169 polymorphic loci. The collection includes the 69 wild lines considered by

H. Ozkan; A. Brandolini; C. Pozzi; S. Effgen; J. Wunder; F. Salamini

2005-01-01

40

A microsatellite map of wheat.  

PubMed Central

Hexaploid bread wheat (Triticum aestivum L. em. Thell) is one of the world's most important crop plants and displays a very low level of intraspecific polymorphism. We report the development of highly polymorphic microsatellite markers using procedures optimized for the large wheat genome. The isolation of microsatellite-containing clones from hypomethylated regions of the wheat genome increased the proportion of useful markers almost twofold. The majority (80%) of primer sets developed are genome-specific and detect only a single locus in one of the three genomes of bread wheat (A, B, or D). Only 20% of the markers detect more than one locus. A total of 279 loci amplified by 230 primer sets were placed onto a genetic framework map composed of RFLPs previously mapped in the reference population of the International Triticeae Mapping Initiative (ITMI) Opata 85 x W7984. Sixty-five microsatellites were mapped at a LOD >2.5, and 214 microsatellites were assigned to the most likely intervals. Ninety-three loci were mapped to the A genome, 115 to the B genome, and 71 to the D genome. The markers are randomly distributed along the linkage map, with clustering in several centromeric regions.

Roder, M S; Korzun, V; Wendehake, K; Plaschke, J; Tixier, M H; Leroy, P; Ganal, M W

1998-01-01

41

Dispersion and domestication shaped the genome of bread wheat.  

PubMed

Despite the international significance of wheat, its large and complex genome hinders genome sequencing efforts. To assess the impact of selection on this genome, we have assembled genomic regions representing genes for chromosomes 7A, 7B and 7D. We demonstrate that the dispersion of wheat to new environments has shaped the modern wheat genome. Most genes are conserved between the three homoeologous chromosomes. We found differential gene loss that supports current theories on the evolution of wheat, with greater loss observed in the A and B genomes compared with the D. Analysis of intervarietal polymorphisms identified fewer polymorphisms in the D genome, supporting the hypothesis of early gene flow between the tetraploid and hexaploid. The enrichment for genes on the D genome that confer environmental adaptation may be associated with dispersion following wheat domestication. Our results demonstrate the value of applying next-generation sequencing technologies to assemble gene-rich regions of complex genomes and investigate polyploid genome evolution. We anticipate the genome-wide application of this reduced-complexity syntenic assembly approach will accelerate crop improvement efforts not only in wheat, but also in other polyploid crops of significance. PMID:23346876

Berkman, Paul J; Visendi, Paul; Lee, Hong C; Stiller, Jiri; Manoli, Sahana; Lorenc, Micha? T; Lai, Kaitao; Batley, Jacqueline; Fleury, Delphine; Simková, Hana; Kubaláková, Marie; Weining, Song; Doležel, Jaroslav; Edwards, David

2013-01-24

42

Characterisation of a gene encoding wheat endosperm starch branching enzyme-I  

Microsoft Academic Search

A genomic DNA fragment from Triticum tauschii, the donor of the wheat D genome, contains a starch branching enzyme-I (SBE-I) gene spread over 6.5?kb. This gene (designated\\u000a wSBE?I-D4) encodes an amino acid sequence identical to that determined for the N-terminus of SBE-I from the hexaploid wheat (T. aestivum) endosperm. Cognate cDNA sequences for wSBE I-D4 were isolated from hexaploid wheat

S. Rahman; Z. Li; S. Abrahams; D. Abbott; R. Appels; M. K. Morell

1999-01-01

43

Multipotent Adult Progenitor Cells  

Microsoft Academic Search

In 2001 the laboratory of Catherine Verfaillie at the University of Minnesota described the multipotent adult progenitor cell\\u000a (MAPC) as a novel progenitor cell present in adult marrow that is biologically and antigenically distinct from the mesenchymal\\u000a stem cell (MSC). MAPCs represent a more primitive progenitor cell population than MSCs and demonstrate remarkable differentiation\\u000a capability along the epithelial, endothelial, neuronal,

Wouter van’t Hof; Niladri Mal; Amy Raber; Ming Zhang; Anthony Ting; Robert Deans

44

Eat Wheat!  

ERIC Educational Resources Information Center

This pamphlet contains puzzles, games, and a recipe designed to teach elementary school pupils about wheat. It includes word games based on the U.S. Department of Agriculture Food Guide Pyramid and on foods made from wheat. The Food Guide Pyramid can be cut out of the pamphlet and assembled as a three-dimensional information source and food guide.…

Idaho Wheat Commission, Boise.

45

The Major Threshability Genes Soft Glume (sog) and Tenacious Glume (Tg), of Diploid and Polyploid Wheat, Trace Their Origin to Independent Mutations at Non-Orthogous Loci  

Technology Transfer Automated Retrieval System (TEKTRAN)

Threshability is an important crop domestication trait. The wild wheat progenitors have tough glumes enveloping the floret that make spikes difficult to thresh, whereas cultivated wheats have soft glumes and are free-threshing. In hexaploid wheat, the glume tenacity gene Tg along with the major dome...

46

Development of high amylose wheat through TILLING  

PubMed Central

Background Wheat (Triticum spp.) is an important source of food worldwide and the focus of considerable efforts to identify new combinations of genetic diversity for crop improvement. In particular, wheat starch composition is a major target for changes that could benefit human health. Starches with increased levels of amylose are of interest because of the correlation between higher amylose content and elevated levels of resistant starch, which has been shown to have beneficial effects on health for combating obesity and diabetes. TILLING (Targeting Induced Local Lesions in Genomes) is a means to identify novel genetic variation without the need for direct selection of phenotypes. Results Using TILLING to identify novel genetic variation in each of the A and B genomes in tetraploid durum wheat and the A, B and D genomes in hexaploid bread wheat, we have identified mutations in the form of single nucleotide polymorphisms (SNPs) in starch branching enzyme IIa genes (SBEIIa). Combining these new alleles of SBEIIa through breeding resulted in the development of high amylose durum and bread wheat varieties containing 47-55% amylose and having elevated resistant starch levels compared to wild-type wheat. High amylose lines also had reduced expression of SBEIIa RNA, changes in starch granule morphology and altered starch granule protein profiles as evaluated by mass spectrometry. Conclusions We report the use of TILLING to develop new traits in crops with complex genomes without the use of transgenic modifications. Combined mutations in SBEIIa in durum and bread wheat varieties resulted in lines with significantly increased amylose and resistant starch contents.

2012-01-01

47

Acc homoeoloci and the evolution of wheat genomes.  

PubMed

The DNA sequences of wheat Acc-1 and Acc-2 loci, encoding the plastid and cytosolic forms of the enzyme acetyl-CoA carboxylase, were analyzed with a view to understanding the evolution of these genes and the origin of the three genomes in modern hexaploid wheat. Acc-1 and Acc-2 loci from each of the wheats Triticum urartu (A genome), Aegilops tauschii (D genome), Triticum turgidum (AB genome), and Triticum aestivum (ABD genome), as well as two Acc-2-related pseudogenes from T. urartu were sequenced. The 2.3-2.4 Mya divergence time calculated here for the three homoeologous chromosomes, on the basis of coding and intron sequences of the Acc-1 genes, is at the low end of other estimates. Our clock was calibrated by using 60 Mya for the divergence between wheat and maize. On the same time scale, wheat and barley diverged 11.6 Mya, based on sequences of Acc and other genes. The regions flanking the Acc genes are not conserved among the A, B, and D genomes. They are conserved when comparing homoeologous genomes of diploid, tetraploid, and hexaploid wheats. Substitution rates in intergenic regions consisting primarily of repetitive sequences vary substantially along the loci and on average are 3.5-fold higher than the Acc intron substitution rates. The composition of the Acc homoeoloci suggests haplotype divergence exceeding in some cases 0.5 Mya. Such variation might result in a significant overestimate of the time since tetraploid wheat formation, which occurred no more than 0.5 Mya. PMID:18599450

Chalupska, D; Lee, H Y; Faris, J D; Evrard, A; Chalhoub, B; Haselkorn, R; Gornicki, P

2008-07-03

48

Wheat: The Whole Story.  

ERIC Educational Resources Information Center

|This publication presents information on wheat. Wheat was originally a wild grass and not native to the United States. Wheat was not planted there until 1777 (and then only as a hobby crop). Wheat is grown on more acres than any other grain in this country. Soft wheats are grown east of the Mississippi River, and hard wheats are grown west of the…

Oklahoma State Dept. of Education, Oklahoma City.

49

Assessment of genetic diversity among Syrian durum (Triticum turgidum ssp. durum) and bread wheat (Triticum aestivum L.) using SSR markers.  

PubMed

Genetic diversity among 49 wheat varieties (37 durum and 12 bread wheat) was assayed using 32 microsatellites representing 34 loci covering almost the whole wheat genome. The polymorphic information content (PIC) across the tested loci ranged from 0 to 0.88 with average values of 0.57 and 0.65 for durum and bread wheat respectively. B genome had the highest mean number of alleles (10.91) followed by A genome (8.3) whereas D genome had the lowest number (4.73). The correlation between PIC and allele number was significant in all genome groups accounting for 0.87, 074 and 0.84 for A, B and D genomes respectively, and over all genomes, the correlation was higher in tetraploid (0.8) than in hexaploid wheat varieties (0.5). The cluster analysis discriminated all varieties and clearly divided the two ploidy levels into two separate clusters that reflect the differences in genetic diversity within each cluster. This study demonstrates that microsatellites markers have unique advantages compared to other molecular and biochemical fingerprinting techniques in revealing the genetic diversity in Syrian wheat varieties that is crucial for wheat improvement. PMID:21254727

Achtar, S; Moualla, M Y; Kalhout, A; Röder, M S; MirAli, N

2010-11-01

50

Cytological and microsatellite mapping of mutant genes for spherical grain and compact spikes in durum wheat  

Microsoft Academic Search

Two mutants for sphaerococcoid seed (MA 16219) and compact spike (MA 17648) were isolated from M3 progeny of durum wheat cultivar, Altaiskaya Niva, mutagenized with chemical mutagens. The chromosomal locations of the genes\\u000a involved were determined by the use of a complete set of D-genome disomic substitutions in durum cultivar, Langdon. The gene\\u000a for sphaerococcoid grain, s\\u000a \\u000a 16219\\u000a , was

K. Kosuge; N. Watanabe; T. Kuboyama; V. M. Melnik; V. I. Yanchenko; M. A. Rosova; N. P. Goncharov

2008-01-01

51

Winter and Specialty Wheat  

Microsoft Academic Search

Wheat is the most widely grown crop in the world. Winter wheat is primarily common wheat (2n = 6x = 42) which has extensive germplasm resources that are used in breeding, often for disease and insect resistance. Though\\u000a wheat can be used as a forage crop and its grain for animal feed, the primary uses of common wheat are to

P. Baenziger; R. Graybosch; D. Van Sanford; W. Berzonsky

52

Wheat Lipids  

Technology Transfer Automated Retrieval System (TEKTRAN)

This article is a chapter of a book entitled “Wheat: Chemistry and Technology”, the 4th edition, K. Khan and P.R. Shewry (eds.), to be published in 2007 following the 3rd edition, Y. Pomeranz (ed.), published in 1988 by AACC International Inc., St. Paul, MN. The chapter covers the subject area of wh...

53

Structural organization of the barley D-hordein locus in comparison with its orthologous regions of wheat genomes.  

PubMed

D hordein, a prolamin storage protein of barley endosperms, is highly homologous to the high molecular weight (HWM) glutenin subunits, which are the major determinants of bread-making quality in wheat flour. In hexaploid wheat (AABBDD), each genome contains two paralogous copies of HMW-glutenin genes that encode the x- and y-type HMW-glutenin subunits. Previously, we reported the sequence analysis of a 102-kb genomic region that contains the HMW-glutenin locus of the D genome from Aegilops tauschii, the donor of the D genome of hexaploid wheat. Here, we present the sequence analysis of a 120-kb D-hordein region of the barley genome, a more distantly related member of the Triticeae grass tribe. Comparative sequence analysis revealed that gene content and order are generally conserved. Genes included in both of these orthologous regions are arranged in the following order: a Xa21-like receptor kinase, an endosperm globulin, an HMW prolamin, and a serine (threonine) protein kinase. However, in the wheat D genome, a region containing both the globulin and HMW-glutenin gene was duplicated, indicating that this duplication event occurred after the separation of the wheat and barley genomes. The intergenic regions are divergent with regard to the sequence and structural organization. It was found that different types of retroelements are responsible for the intergenic structure divergence in the wheat and barley genomes. In the barley region, we identified 16 long terminal repeat (LTR) retrotransposons in three distinct nested clusters. These retroelements account for 63% of the contig sequence. In addition, barley D hordein was compared with wheat HMW glutenins in terms of cysteine residue conservation and repeat domain organization. PMID:14663527

Gu, Yong Qiang; Anderson, Olin D; Londeorë, Cynthia F; Kong, Xiuying; Chibbar, Ravindra N; Lazo, Gerard R

2003-12-01

54

Molecular genetic characterization of the Lr34/Yr18 slow rusting resistance gene region in wheat.  

PubMed

Wheat expressed sequence tags (wESTs) were identified in a genomic interval predicted to span the Lr34/Yr18 slow rusting region on chromosome 7DS and that corresponded to genes located in the syntenic region of rice chromosome 6 (between 2.02 and 2.38 Mb). A subset of the wESTs was also used to identify corresponding bacterial artificial chromosome (BAC) clones from the diploid D genome of wheat (Aegilops tauschii). Conservation and deviation of micro-colinearity within blocks of genes were found in the D genome BACs relative to the orthologous sequences in rice. Extensive RFLP analysis using the wEST derived clones as probes on a panel of wheat genetic stocks with or without Lr34/Yr18 revealed monomorphic patterns as the norm in this region of the wheat genome. A similar pattern was observed with single nucleotide polymorphism analysis on a subset of the wEST derived clones and subclones from corresponding D genome BACs. One exception was a wEST derived clone that produced a consistent RFLP pattern that distinguished the Lr34/Yr18 genetic stocks and well-established cultivars known either to possess or lack Lr34/Yr18. Conversion of the RFLP to a codominant sequence tagged site (csLV34) revealed a bi-allelic locus, where a variant size of 79 bp insertion in an intron sequence was associated with lines or cultivars that lacked Lr34/Yr18. This association with Lr34/Yr18 was validated in wheat cultivars from diverse backgrounds. Genetic linkage between csLV34 and Lr34/Yr18 was estimated at 0.4 cM. PMID:17008991

Lagudah, E S; McFadden, H; Singh, R P; Huerta-Espino, J; Bariana, H S; Spielmeyer, W

2006-09-29

55

Evolutionary Genomics of Wheat  

Technology Transfer Automated Retrieval System (TEKTRAN)

Wheat is the world’s largest and most important food crop for direct human consumption, therefore, continued wheat improvement is paramount for feeding an ever-increasing human population. Wheat improvement is tightly associated with the characterization and understanding of wheat evolution and gene...

56

Hematopoietic progenitor cell collection.  

PubMed

Hematopoietic progenitor cells can be mobilized from the bone marrow microenvironment into the peripheral blood following treatment of patients with myeloid cytokines (GCSF, GMCSF, IL3), a CXCR4 antagonist (Plerixafor) and/or following a hematopoietic recovery from cytotoxic chemotherapy. The hematopoietic stem and progenitor cells are contained within the mononuclear cell fraction of peripheral blood and can be collected by apheresis in which the cellular constituents of the blood are separated on the basis of their buoyant density. Modern apheresis allows processing of five or more blood volumes (24 L or more) over a 4-5-h period to efficiently remove and separate more than 70 % of the CD34 positive cell progenitors present to blood. Management of a patient undergoing apheresis requires careful attention to venous access, calcium placement to counteract the effects of the citrate uses anticoagulant and hemodynamic monitoring. The principles of setting up the COBE spectra and its operation are reviewed. Management of common toxicities including hypocalcemia, allergic reactions, and vasovagal reactions are described in the next chapter. PMID:22890924

Marlow, S Darlene; House, Myra

2012-01-01

57

Proteome analysis of diploid, tetraploid and hexaploid wheat: towards understanding genome interaction in protein expression.  

PubMed

Hexaploid wheat (Triticum aestivum L.) is derived from a complex hybridization procedure involving three diploid species carrying the A, B and D genomes. The proteome patterns of diploid, tetraploid and hexaploid wheat were analyzed to explore the genome interaction in protein expression. At least two species from each of the diploid and tetraploid were used to compare their proteome maps with a hexaploid wheat cv. Chinese Spring. The ancestral cultivars were selected based on their history of closeness with the cultivated wheat. Proteins were extracted from seed flour and separated by two-dimensional electrophoresis (2-DE) with isoelectric focusing of pH range from 4-10. 2-DE maps of cultivated and ancestral species were analyzed by computer assisted image analyzer. The region of high molecular weight glutenin subunits of hexaploid wheat showed similarity with those of the diploid donors, BB and DD genomes. The omega gliadin, which is controlled by B genome in common wheat, was assumed to have evolved as a result of interaction between AA and BB genomes. The low molecular weight glutenins and alpha and beta gliadin regions were contributed by the three genomes. This result suggests that the function of donor genomes particularly in the expression of proteins in hexaploid wheat is not totally independent; rather it is the product of interactions among the diploid genomes in the hexaploid nuclear constitutions. The expression of nonstorage proteins was affected substantially due to the removal of the D genome from hexaploid constitution. Location of the structural gene controlling one of the alpha amylase inhibitor proteins in the nonstorage protein region was identified in the short arm of chromosome 3D. PMID:12687621

Islam, Nazrul; Tsujimoto, Hisashi; Hirano, Hisashi

2003-04-01

58

Vrn-D4 is a vernalization gene located on the centromeric region of chromosome 5D in hexaploid wheat  

Microsoft Academic Search

Natural variation in wheat requirement of long exposures to cold temperatures to accelerate flowering (vernalization) is mainly\\u000a controlled by the Vrn-1, Vrn-2, Vrn-3, and Vrn-4 loci. The first three loci have been well characterized, but limited information is available for Vrn-4. So far, natural variation for Vrn-4 has been detected only in the D genome (Vrn-D4), and genetic stocks for

Tetsuya Yoshida; Hidetaka Nishida; Jie Zhu; Rebecca Nitcher; Assaf Distelfeld; Yukari Akashi; Kenji Kato; Jorge Dubcovsky

2010-01-01

59

Photoperiod insensitive Ppd-A1a mutations in tetraploid wheat (Triticum durum Desf.).  

PubMed

Variation in photoperiod response plays an important role in adapting crops to agricultural environments. In hexaploid wheat, mutations conferring photoperiod insensitivity (flowering after a similar time in short or long days) have been mapped on the 2B (Ppd-B1) and 2D (Ppd-D1) chromosomes in colinear positions to the 2H Ppd-H1 gene of barley. No A genome mutation is known. On the D genome, photoperiod insensitivity is likely to be caused by deletion of a regulatory region that causes misexpression of a member of the pseudo-response regulator (PRR) gene family and activation of the photoperiod pathway irrespective of day length. Photoperiod insensitivity in tetraploid (durum) wheat is less characterized. We compared pairs of near-isogenic lines that differ in photoperiod response and showed that photoperiod insensitivity is associated with two independent deletions of the A genome PRR gene that cause altered expression. This is associated with induction of the floral regulator FT. The A genome deletions and the previously described D genome deletion of hexaploid wheat remove a common region, suggesting a shared mechanism for photoperiod insensitivity. The identification of the A genome mutations will allow characterization of durum wheat germplasm and the construction of genotypes with novel combinations of photoperiod insensitive alleles. PMID:18839130

Wilhelm, Edward P; Turner, Adrian S; Laurie, David A

2008-10-07

60

Wheat grass selection  

NSDL National Science Digital Library

The wheat grass on the right is not tolerant of high salinity, or high salt conditions. The wheat grass on the left is a hybrid that has a high salt tolerance. It grows well in high salinity environments.

Richard Wang (USDA;ARS)

2006-09-25

61

Processing Wheat for Food  

NSDL National Science Digital Library

Teachers' Domain presents this interactive lesson on wheat processing, including an introduction to the five kinds of wheat grown in the US and the anatomy of wheat. The module then moves through the six steps in wheat processing: cleaning, conditioning, blending, breaking, sieving, and reducing. Each step is animated to help students visualize the process. On the site, visitors will also find a supplemental background essay, discussion questions, and standards alignment from Teachers' Domain.

2010-10-07

62

U. S. Wheat Industry.  

National Technical Information Service (NTIS)

U.S. wheat production doubled between 1950 and 1975. Improved yields per acre accounted for most of the increase. Since 1974, however, the growth in U.S. wheat yields per acre has leveled off. About half of the U.S. wheat crop is exported, but the somewha...

W. G. Heid

1979-01-01

63

Wheat Stripe Rust  

Technology Transfer Automated Retrieval System (TEKTRAN)

This is a chapter on wheat stripe rust in a book entitled “Wheat: Science and Trade”. The chapter provides an overview on various aspects of wheat stripe rust and control, including distribution and epidemiology; origin and historical importance; taxonomy, lifecycle, and host range; genetic variati...

64

Amplification of DNA sequences in wheat and its relatives: the Dgas44 and R350 families of repetitive sequences.  

PubMed

The sequence of a Triticum tauschii genomic clone representing a family of D-genome amplified DNA sequences, designated Dgas44, is reported. The Dgas44 sequence occurs on all chromosomes of the D genome of wheat, Triticum aestivum, and in situ hybridization revealed it to be evenly dispersed on all seven chromosome pairs. An internal HindIII fragment of Dgas44, designated Dgas44-3, defines the highly amplified region that is specific to the D genome. The polymerase chain reaction was used to amplify a 236-bp fragment within Dgas44-3 from chromosomes 1D, 2D, 3D, 4D, 5D, and 7D, and identical copies of this region of the Dgas44-3 sequence were found among the isolates from each of the chromosomes. The Dgas44-3 sequence population from specific chromosomes differed on average by 0.22% from the original Dgas44 sequence. The Dgas44 sequence was found to differentiate between the D genome present in T. aestivum, T. tauschii, hexaploid T. crassum, T. cylindricum, T. ventricosum, in which the sequence was present in a highly amplified form and T. juvenale, T. syriacum, and tetraploid T. crassum where the sequence family was difficult to detect. Another class of amplified sequences previously considered to be rye "specific." R350, was isolated from tetraploid wheat and its dispersed distribution on chromosomes was similar to the Dgas44 family in T. tauschii. In contrast with the Dgas44 sequence family, genome specificity for the remnant R350 sequence family was not evident since it was present on all wheat chromosomes. PMID:8200519

McNeil, D; Lagudah, E S; Hohmann, U; Appels, R

1994-04-01

65

Lung stem and progenitor cells.  

PubMed

Over the past few years, new insights have been added to the study of stem cells in the adult lung. The exploration of endogenous lung progenitors as well as the study of exogenously delivered stem cell populations holds promise for advancing our understanding of the biology of lung repair mechanisms. Moreover, it opens new possibilities for the use of stem cell therapy for the development of regenerative medicine approaches for the treatment of lung disease. Here, we discuss the main types of lung epithelial progenitor populations; the potential of endothelial progenitors, mesenchymal stem cells and embryonic stem cells for lung therapy, as well as summarize the cellular mechanisms involved. PMID:23406722

Ardhanareeswaran, Karthikeyan; Mirotsou, Maria

2013-02-11

66

Circulating Progenitor Cells and Scleroderma  

PubMed Central

Scleroderma (systemic sclerosis) is a disease of unknown origins that involves tissue ischemia and fibrosis in the skin and internal organs such as the lungs. The tissue ischemia is due to a lack of functional blood vessels and an inability to form new blood vessels. Bone marrow–derived circulating endothelial progenitor cells play a key role in blood vessel repair and neovascularization. Scleroderma patients appear to have defects in the number and function of circulating endothelial progenitor cells. Scleroderma patients also develop fibrotic lesions, possibly as the result of tissue ischemia. Fibroblast-like cells called fibrocytes that differentiate from a different pool of bone marrow–derived circulating progenitor cells seem to be involved in this process. Manipulating the production, function, and differentiation of circulating progenitor cells represents an exciting new possibility for treating scleroderma.

2010-01-01

67

Genes encoding plastid acetylCoA carboxylase and 3-phosphoglycerate kinase of the Triticum\\/Aegilops complex and the evolutionary history of polyploid wheat  

Microsoft Academic Search

The classic wheat evolutionary history is one of adaptive radiation of the diploid Triticum\\/Aegilops species (A, S, D), genome convergence and divergence of the tetraploid (Triticum turgidum AABB, and Triticum timopheevii AAGG) and hexaploid (Triticum aestivum, AABBDD) species. We analyzed Acc-1 (plastid acetyl-CoA carboxylase) and Pgk-1 (plastid 3-phosphoglycerate kinase) genes to determine phylogenetic relationships among Triticum and Aegilops species of

Shaoxing Huang; Anchalee Sirikhachornkit; Xiujuan Su; Justin Faris; Bikram Gill; Robert Haselkorn; Piotr Gornicki

2002-01-01

68

High level of conservation between genes coding for the GAMYB transcription factor in barley ( Hordeum vulgare L.) and bread wheat ( Triticum aestivum L.) collections  

Microsoft Academic Search

The transcription factor GAMYB is involved in gibberellin signalling in cereal aleurone cells and in plant developmental processes.\\u000a Nucleotide diversity of HvGAMYB and TaGAMYB was investigated in 155 barley (Hordeum vulgare) and 42 wheat (Triticum aestivum) accessions, respectively. Polymorphisms defined 18 haplotypes in the barley collection and 1, 7 and 3 haplotypes for the\\u000a A, B, and D genomes of

Grit Haseneyer; Catherine Ravel; Mireille Dardevet; François Balfourier; Pierre Sourdille; Gilles Charmet; Dominique Brunel; Sascha Sauer; Hartwig H. Geiger; Andreas Graner; Silke Stracke

2008-01-01

69

Wheat Evolution, Domestication, and Improvement  

Microsoft Academic Search

SUMMARY (1) Wheat is the world's largest and most important food crop for direct human con- sumption; therefore, continued wheat improvement is paramount for feeding an ever-increasing human population. (2) Wheat improvement is tightly associated with the characterization and understand- ing of wheat evolution and the genetic diversifi cation of various wheat species and relatives. The evolution of the genus

Perry Gustafson; Olga Raskina; XueFeng Ma; Eviatar Nevo

70

Hepatic progenitor cells.  

PubMed

Liver diseases are associated with a marked reduction in the viable mass of hepatocytes. The most severe cases of liver disease (liver failure) are treated by orthotopic liver transplantation. One alternative to whole organ transplantation for patients with hepatic failure (and hereditary liver disease) is hepatocyte transplantation. However, there is a serious limitation to the treatment of liver diseases either by whole organ or hepatocyte transplantation, and that is the shortage of organ donors. Therefore, to overcome the problem of organ shortage, additional sources of hepatocytes must be found. Alternative sources of cells for transplantation have been proposed including embryonic stem cells, immortalised liver cells and differentiated cells. One other source of cells for transplantation found in the adult liver is the progeny of stem cells. These cells are termed hepatic progenitor cells (HPCs). The therapeutic potential of HPCs lies in their ability to proliferate and differentiate into hepatocytes and cholangiocytes. However, using HPCs as a cell therapy cannot be exploited fully until the mechanisms governing hepatocyte differentiation are elucidated. Here, we discuss the fundamental cellular and molecular elements required for HPC differentiation to hepatocytes. PMID:20957497

Sangan, Caroline Beth; Tosh, David

2010-10-19

71

Transcriptional profiling in response to terminal drought stress reveals differential responses along the wheat genome  

PubMed Central

Background Water stress during grain filling has a marked effect on grain yield, leading to a reduced endosperm cell number and thus sink capacity to accumulate dry matter. The bread wheat cultivar Chinese Spring (CS), a Chinese Spring terminal deletion line (CS_5AL-10) and the durum wheat cultivar Creso were subjected to transcriptional profiling after exposure to mild and severe drought stress at the grain filling stage to find evidences of differential stress responses associated to different wheat genome regions. Results The transcriptome analysis of Creso, CS and its deletion line revealed 8,552 non redundant probe sets with different expression levels, mainly due to the comparisons between the two species. The drought treatments modified the expression of 3,056 probe sets. Besides a set of genes showing a similar drought response in Creso and CS, cluster analysis revealed several drought response features that can be associated to the different genomic structure of Creso, CS and CS_5AL-10. Some drought-related genes were expressed at lower level (or not expressed) in Creso (which lacks the D genome) or in the CS_5AL-10 deletion line compared to CS. The chromosome location of a set of these genes was confirmed by PCR-based mapping on the D genome (or the 5AL-10 region). Many clusters were characterized by different level of expression in Creso, CS and CS_AL-10, suggesting that the different genome organization of the three genotypes may affect plant adaptation to stress. Clusters with similar expression trend were grouped and functional classified to mine the biological mean of their activation or repression. Genes involved in ABA, proline, glycine-betaine and sorbitol pathways were found up-regulated by drought stress. Furthermore, the enhanced expression of a set of transposons and retrotransposons was detected in CS_5AL-10. Conclusion Bread and durum wheat genotypes were characterized by a different physiological reaction to water stress and by a substantially different molecular response. The genome organization accounted for differences in the expression level of hundreds of genes located on the D genome or controlled by regulators located on the D genome. When a genomic stress (deletion of a chromosomal region) was combined with low water availability, a molecular response based on the activation of transposons and retrotransposons was observed.

Aprile, Alessio; Mastrangelo, Anna M; De Leonardis, Anna M; Galiba, Gabor; Roncaglia, Enrica; Ferrari, Francesco; De Bellis, Luigi; Turchi, Luana; Giuliano, Giovanni; Cattivelli, Luigi

2009-01-01

72

Revealed Competitive Advantage for Wheat.  

National Technical Information Service (NTIS)

A new indicator of trade performance, called 'revealed competitive advantage' (RCA), is used to examine the changing nature of wheat competitiveness and noncompetitiveness. Time series RCA measures for 5 wheat-exporting countries and 20 wheat-importing co...

T. Vollrath

1987-01-01

73

The origin of the B-genome of bread wheat (Triticum aestivum L.).  

PubMed

Understanding the origin of cultivated wheats would further their genetic improvement. The hexaploid bread wheat (Triticum aestivum L., AABBDD) is believed to have originated through one or more rare hybridization events between Aegilops tauschii (DD) and the tetraploid T. turgidum (AABB). Progenitor of the A-genome of the tetraploid and hexaploid wheats has generally been accepted to be T. urartu. In spite of the large number of attempts and published reports about the origin of the B-genome in cultivated wheats, the donor of the B-genome is still relatively unknown and controversial and, hence, remains open. This genome has been found to be closely related to the S-genome of the Sitopsis section (Ae. speltoides, Ae. longissima, Ae. sharonensis, Ae. searsii, and Ae. bicornis) of the genus Aegilops L. Among Sitopsis species, the most positive evidence has been accumulated for Ae. speltoides as the progenitor of the B-genome. Therefore, one or more of the Sitopsis species were proposed frequently as the B-genome donor. Although several reviews have been written on the origin of the genomes of wheat over the years, this paper will attempt for the first time to review the immense literature on the subject, with a particular emphasis on the B-genome which has attracted a huge attention over some 100 years. The ambiguity and conflicting results in most of the methods employed in deducing the precise B-genome donor/s to bread wheat are also discussed. PMID:23755530

Haider, N

2013-03-01

74

Population- and genome-specific patterns of linkage disequilibrium and SNP variation in spring and winter wheat (Triticum aestivum L.)  

PubMed Central

Background Single nucleotide polymorphisms (SNPs) are ideally suited for the construction of high-resolution genetic maps, studying population evolutionary history and performing genome-wide association mapping experiments. Here, we used a genome-wide set of 1536 SNPs to study linkage disequilibrium (LD) and population structure in a panel of 478 spring and winter wheat cultivars (Triticum aestivum) from 17 populations across the United States and Mexico. Results Most of the wheat oligo pool assay (OPA) SNPs that were polymorphic within the complete set of 478 cultivars were also polymorphic in all subpopulations. Higher levels of genetic differentiation were observed among wheat lines within populations than among populations. A total of nine genetically distinct clusters were identified, suggesting that some of the pre-defined populations shared significant proportion of genetic ancestry. Estimates of population structure (FST) at individual loci showed a high level of heterogeneity across the genome. In addition, seven genomic regions with elevated FST were detected between the spring and winter wheat populations. Some of these regions overlapped with previously mapped flowering time QTL. Across all populations, the highest extent of significant LD was observed in the wheat D-genome, followed by lower LD in the A- and B-genomes. The differences in the extent of LD among populations and genomes were mostly driven by differences in long-range LD ( > 10 cM). Conclusions Genome- and population-specific patterns of genetic differentiation and LD were discovered in the populations of wheat cultivars from different geographic regions. Our study demonstrated that the estimates of population structure between spring and winter wheat lines can identify genomic regions harboring candidate genes involved in the regulation of growth habit. Variation in LD suggests that breeding and selection had a different impact on each wheat genome both within and among populations. The higher extent of LD in the wheat D-genome versus the A- and B-genomes likely reflects the episodes of recent introgression and population bottleneck accompanying the origin of hexaploid wheat. The assessment of LD and population structure in this assembled panel of diverse lines provides critical information for the development of genetic resources for genome-wide association mapping of agronomically important traits in wheat.

2010-01-01

75

Wheat Evolution: Dough Washing  

NSDL National Science Digital Library

In this activity (page 5), learners investigate the evolution of wheat by washing different types of dough with water and comparing the results. The evolution of wheat from wild grasses demonstrates the dramatic effect of both natural and directed evolution on the structure of a crop plant and the chemical makeup of the product harvested from it. These activities illustrate the changes to both the structure and the chemistry of the wheat plant.

Council, Biotechnology A.

2012-01-01

76

Functional characterisation of wheat Pgip genes reveals their involvement in the local response to wounding.  

PubMed

Polygalacturonase-inhibiting proteins (PGIPs) are cell wall leucine-rich repeat (LRR) proteins involved in plant defence. The hexaploid wheat (Triticum aestivum, genome AABBDD) genome contains one Pgip gene per genome. Tapgip1 (B genome) and Tapgip2 (D genome) are expressed in all tissues, whereas Tapgip3 (A genome) is inactive because of a long terminal repeat, Copia retrotransposon insertion within the coding region. To verify whether Tapgip1 and Tapgip2 encode active PGIPs and are involved in the wheat defence response, we expressed them transiently and analysed their expression under stress conditions. Neither TaPGIP1 nor TaPGIP2 showed inhibition activity in vitro against fungal polygalacturonases. Moreover, a wheat genotype (T. turgidum ssp. dicoccoides) lacking active homologues of Tapgip1 or Tapgip2 possesses PGIP activity. At transcript level, Tapgip1 and Tapgip2 were both up-regulated after fungal infection and strongly induced following wounding. This latter result has been confirmed in transgenic wheat plants expressing the ?-glucuronidase (GUS) gene under control of the 5'-flanking region of Tdpgip1, a homologue of Tapgip1 with an identical sequence. Strong and transient GUS staining was mainly restricted to the damaged tissues and was not observed in adjacent tissues. Taken together, these results suggest that Tapgips and their homologues are involved in the wheat defence response by acting at the site of the lesion caused by pathogen infection. PMID:23574379

Janni, M; Bozzini, T; Moscetti, I; Volpi, C; D'Ovidio, R

2013-04-10

77

Introgression of a leaf rust resistance gene from Aegilops caudata to bread wheat.  

PubMed

Rusts are the most important biotic constraints limiting wheat productivity worldwide. Deployment of cultivars with broad spectrum rust resistance is the only environmentally viable option to combat these diseases. Identification and introgression of novel sources of resistance is a continuous process to combat the ever evolving pathogens. The germplasm of nonprogenitor Aegilops species with substantial amount of variability has been exploited to a limited extent. In the present investigation introgression, inheritance and molecular mapping of a leaf rust resistance gene of Ae. caudata (CC) acc. pau3556 in cultivated wheat were undertaken. An F(2) population derived from the cross of Triticum aestivum cv. WL711 - Ae. caudata introgression line T291-2 with wheat cultivar PBW343 segregated for a single dominant leaf rust resistance gene at the seedling and adult plant stages. Progeny testing in F(3) confirmed the introgression of a single gene for leaf rust resistance. Bulked segregant analysis using polymorphic D-genome-specific SSR markers and the cosegregation of the 5DS anchored markers (Xcfd18, Xcfd78, Xfd81 and Xcfd189) with the rust resistance in the F(2) population mapped the leaf rust resistance gene (LrAC) on the short arm of wheat chromosome 5D. Genetic complementation and the linked molecular markers revealed that LrAC is a novel homoeoallele of an orthologue Lr57 already introgressed from the 5M chromosome of Ae. geniculata on 5DS of wheat. PMID:22942085

Riar, Amandeep Kaur; Kaur, Satinder; Dhaliwal, H S; Singh, Kuldeep; Chhuneja, Parveen

2012-08-01

78

Embryonic heart progenitors and cardiogenesis.  

PubMed

The mammalian heart is a highly specialized organ, comprised of many different cell types arising from distinct embryonic progenitor populations during cardiogenesis. Three precursor populations have been identified to contribute to different myocytic and nonmyocytic cell lineages of the heart: cardiogenic mesoderm cells (CMC), the proepicardium (PE), and cardiac neural crest cells (CNCCs). This review will focus on molecular cues necessary for proper induction, expansion, and lineage-specific differentiation of these progenitor populations during cardiac development in vivo. Moreover, we will briefly discuss how the knowledge gained on embryonic heart progenitor biology can be used to develop novel therapeutic strategies for the management of congenital heart disease as well as for improvement of cardiac function in ischemic heart disease. PMID:24086063

Brade, Thomas; Pane, Luna S; Moretti, Alessandra; Chien, Kenneth R; Laugwitz, Karl-Ludwig

2013-10-01

79

Genetic and Epigenetic Alteration among Three Homoeologous Genes of a Class E MADS Box Gene in Hexaploid Wheat[W][OA  

PubMed Central

Bread wheat (Triticum aestivum) is a hexaploid species with A, B, and D ancestral genomes. Most bread wheat genes are present in the genome as triplicated homoeologous genes (homoeologs) derived from the ancestral species. Here, we report that both genetic and epigenetic alterations have occurred in the homoeologs of a wheat class E MADS box gene. Two class E genes are identified in wheat, wheat SEPALLATA (WSEP) and wheat LEAFY HULL STERILE1 (WLHS1), which are homologs of Os MADS45 and Os MADS1 in rice (Oryza sativa), respectively. The three wheat homoeologs of WSEP showed similar genomic structures and expression profiles. By contrast, the three homoeologs of WLHS1 showed genetic and epigenetic alterations. The A genome WLHS1 homoeolog (WLHS1-A) had a structural alteration that contained a large novel sequence in place of the K domain sequence. A yeast two-hybrid analysis and a transgenic experiment indicated that the WLHS1-A protein had no apparent function. The B and D genome homoeologs, WLHS1-B and WLHS1-D, respectively, had an intact MADS box gene structure, but WLHS1-B was predominantly silenced by cytosine methylation. Consequently, of the three WLHS1 homoeologs, only WLHS1-D functions in hexaploid wheat. This is a situation where three homoeologs are differentially regulated by genetic and epigenetic mechanisms.

Shitsukawa, Naoki; Tahira, Chikako; Kassai, Ken-ichiro; Hirabayashi, Chizuru; Shimizu, Tomoaki; Takumi, Shigeo; Mochida, Keiichi; Kawaura, Kanako; Ogihara, Yasunari; Murai, Koji

2007-01-01

80

Stem Cell and Progenitor Cell Expansion.  

National Technical Information Service (NTIS)

The present invention provides compositions and methods for the expansion of stem cells and progenitor cells with adiponectin, adiponectin variants, or other molecules that activate adiponectin receptors and signaling, whereby the stem or progenitor cells...

L. DiMascio M. Uqoezwa Q. Wu T. Reya

2005-01-01

81

The Progenitors of Thermonuclear Supernovae  

SciTech Connect

In the framework of the rotating Double Degenerate Scenario for type Ia Supernovae progenitors, we show that the dichotomy between explosive events in early and late type galaxies can be easily explained. Assuming that more massive progenitors produce slow-decline (high-luminosity) light curve, it comes out that, at the current age of the Universe, in late type galaxies the continuous star formation provides very massive exploding objects (prompt component) corresponding to slow-decline (bright) SNe; on the other hand, in early type galaxies, where star formation ended many billions years ago, only low mass ''normal luminosity'' objects (delayed component) are present.

Piersanti, L.; Straniero, O. [INAF-OACTe via M. Maggini, snc., 64100 Teramo (Italy); Tornambe, A. [OAR-via di Frascati, 33, 00040 Monte Porzio Catone (Italy) (Italy); Dominguez, I. [Depto. Fysica Teorica y del Cosmos, Univ. Granada (Spain)

2009-05-03

82

Wheat Quality Council Hard Spring Wheat Technical Committee 2010 Crop  

Technology Transfer Automated Retrieval System (TEKTRAN)

Breeders’ experimental lines of wheat are evaluated for overall quality before being released for commercial production. The Hard Spring Wheat Technical Committee provides milling and baking quality data on breeders’ experimental lines of wheat that are annually submitted to the Wheat Quality Counc...

83

Neural progenitors from human embryonic stem cells  

Microsoft Academic Search

The derivation of neural progenitor cells from human embryonic stem (ES) cells is of value both in the study of early human neurogenesis and in the creation of an unlimited source of donor cells for neural transplantation therapy. Here we report the generation of enriched and expandable preparations of proliferating neural progenitors from human ES cells. The neural progenitors could

Pavel Itsykson; Tikva Turetsky; Martin F. Pera; Etti Reinhartz; Anna Itzik; Tamir Ben-Hur; Benjamin E. Reubinoff

2001-01-01

84

The discovery of endothelial progenitor cells  

Microsoft Academic Search

Although the earliest sites of hematopoietic cell and endothelial cell differentiation in the yolk sac blood islands were identified about 100 years ago, cells with hemangioblast properties have not yet been identified in vivo. Endothelial cells differentiate from angioblasts in the embryo and from endothelial progenitor cells, mesoangioblasts and multipotent adult progenitor cells in the adult bone marrow. Endothelial progenitor

Domenico Ribatti

2007-01-01

85

Agrometeorology and Wheat Production  

Technology Transfer Automated Retrieval System (TEKTRAN)

Winter wheat phenology varies among shoots on the plant to main stems on plants within a plot to locations across a landscape. Most often phenological measurements have focused on small treatment plots under presumably similar soils and topography. Many models exist to predict wheat phenology for sm...

86

Registration of 'Snowmass' wheat  

Technology Transfer Automated Retrieval System (TEKTRAN)

‘Snowmass’ (Reg. No. CV-1050, PI 658597) hard white winter wheat (Triticum aestivum L.) was developed by the Colorado Agricultural Experiment Station and released in July 2009 through a marketing agreement with the Colorado Wheat Research Foundation. In addition to researchers at Colorado State Uni...

87

Registration of ‘Ripper’ Wheat  

Technology Transfer Automated Retrieval System (TEKTRAN)

‘Ripper’ (Reg. No. CV-1016, PI 644222) hard red winter wheat (Triticum aestivum L.) was developed by the Colorado Agricultural Experiment Station and released in August 2006 through an exclusive marketing agreement with the Colorado Wheat Research Foundation. In addition to researchers at Colorado S...

88

Registration of ‘Kelse’ wheat  

Technology Transfer Automated Retrieval System (TEKTRAN)

Hard red spring (HRS) wheat (Triticum aestivum L.) grain must have high grain protein concentration (GPC) to maximize market value. The objective of this research was to develop a HRS wheat cultivar with high GPC and durable resistance to stripe rust (Puccinia striiformis Westend f. sp. tritici), a ...

89

INVISIBLE COATINGS FOR WHEAT KERNELS  

Technology Transfer Automated Retrieval System (TEKTRAN)

It is occasionally necessary to tag wheat kernels without altering their appearance. Coatings have potential applications to tag wheat of a particular color or protein class, diseased wheat such as karnal bunt or genetically modified wheat. This methodology will aid in the development of calibrati...

90

Wheat Evolution: Sedimentation Testing  

NSDL National Science Digital Library

In this activity (p.8-9 of PDF), learners investigate the evolution of wheat by conducting sedimentation tests on different flours. The evolution of wheat from wild grasses demonstrates the dramatic effect of both natural and directed evolution on the structure of a crop plant and the chemical makeup of the product harvested from it. These activities illustrate the changes to both the structure and the chemistry of the wheat plant. Note: Sedimentation test can also be done using SDS detergent and lactic acid instead of soap and vinegar.

Council, Biotechnology A.

2012-01-01

91

Wheat Evolution: Dough Rising  

NSDL National Science Digital Library

In this activity (p.6-7 of PDF), learners investigate the evolution of wheat by creating dough from different flours, observing the samples of dough as they rise, and then baking the dough. The evolution of wheat from wild grasses demonstrates the dramatic effect of both natural and directed evolution on the structure of a crop plant and the chemical makeup of the product harvested from it. These activities illustrate the changes to both the structure and the chemistry of the wheat plant.

Council, Biotechnology A.

2012-01-01

92

Cardiac Stem and Progenitor Cells  

Microsoft Academic Search

\\u000a Since the early days of cardiovascular biology, it has been believed that mammalian adult cardiomyocytes exit from the cell\\u000a cycle soon after birth, with the total number of cardiomyocytes being pre-determined. Recently, the identification of resident\\u000a cardiac stem\\/progenitor cells by several independent laboratories has challenged this long-held paradigm and has provoked\\u000a an exponential increase in the number of investigations. As

Ronglih Liao; Regina L. Sohn

93

Endothelial Progenitor Cells for Vasculogenesis  

NSDL National Science Digital Library

Postnatal vasculogenesis is considered to be involved in neovascularization of adult tissues, because bone marrow-derived endothelial progenitor cells (EPCs) were isolated from circulating mononuclear cells in peripheral blood and were shown to incorporate into sites of physiological and pathological neovascularization and to differentiate into mature endothelial cells. EPCs might have an attractive potential therapeutic application for cardiovascular ischemic diseases as a novel cell-based strategy mainly via a vasculogenesis mechanism.

Satoshi Murasawa (Kobe Institute of Biomedical Research and Innovation/RIKEN Department of Regenerative Medicine and Research); Takayuki Asahara (Tokai University School of Medicine Department of Regenerative Medicine Science)

2005-02-01

94

PROGENITORS OF RECOMBINING SUPERNOVA REMNANTS  

SciTech Connect

Usual supernova remnants have either ionizing plasma or plasma in collisional ionization equilibrium, i.e., the ionization temperature is lower than or equal to the electron temperature. However, the existence of recombining supernova remnants, i.e., supernova remnants with ionization temperature higher than the electron temperature, has been recently confirmed. One suggested way to have recombining plasma in a supernova remnant is to have a dense circumstellar medium at the time of the supernova explosion. If the circumstellar medium is dense enough, collisional ionization equilibrium can be established in the early stage of the evolution of the supernova remnant and subsequent adiabatic cooling, which occurs after the shock wave gets out of the dense circumstellar medium, makes the electron temperature lower than the ionization temperature. We study the circumstellar medium around several supernova progenitors and show which supernova progenitors can have a circumstellar medium dense enough to establish collisional ionization equilibrium soon after the explosion. We find that the circumstellar medium around red supergiants (especially massive ones) and the circumstellar medium dense enough to make Type IIn supernovae can establish collisional ionization equilibrium soon after the explosion and can evolve to become recombining supernova remnants. Wolf-Rayet stars and white dwarfs have the possibility to be recombining supernova remnants but the fraction is expected to be very small. As the occurrence rate of the explosions of red supergiants is much higher than that of Type IIn supernovae, the major progenitors of recombining supernova remnants are likely to be red supergiants.

Moriya, Takashi J., E-mail: takashi.moriya@ipmu.jp [Kavli Institute for the Physics and Mathematics of the Universe, Todai Institutes for Advanced Study, University of Tokyo, Kashiwanoha 5-1-5, Kashiwa, Chiba 277-8583 (Japan)

2012-05-01

95

Wheat for Kids! [and] Teacher's Guide.  

ERIC Educational Resources Information Center

"Wheat for Kids" contains information at the elementary school level about: the structure of the wheat kernel; varieties of wheat and their uses; growing wheat; making wheat dough; the U.S. Department of Agriculture Food Guide Pyramid and nutrition; Idaho's part of the international wheat market; recipes; and word games based on the information…

Idaho Wheat Commission, Boise.

96

Wheat for Kids! [and] Teacher's Guide.  

ERIC Educational Resources Information Center

|"Wheat for Kids" contains information at the elementary school level about: the structure of the wheat kernel; varieties of wheat and their uses; growing wheat; making wheat dough; the U.S. Department of Agriculture Food Guide Pyramid and nutrition; Idaho's part of the international wheat market; recipes; and word games based on the information…

Idaho Wheat Commission, Boise.

97

Nucleotide diversity maps reveal variation in diversity among wheat genomes and chromosomes  

PubMed Central

Background A genome-wide assessment of nucleotide diversity in a polyploid species must minimize the inclusion of homoeologous sequences into diversity estimates and reliably allocate individual haplotypes into their respective genomes. The same requirements complicate the development and deployment of single nucleotide polymorphism (SNP) markers in polyploid species. We report here a strategy that satisfies these requirements and deploy it in the sequencing of genes in cultivated hexaploid wheat (Triticum aestivum, genomes AABBDD) and wild tetraploid wheat (Triticum turgidum ssp. dicoccoides, genomes AABB) from the putative site of wheat domestication in Turkey. Data are used to assess the distribution of diversity among and within wheat genomes and to develop a panel of SNP markers for polyploid wheat. Results Nucleotide diversity was estimated in 2114 wheat genes and was similar between the A and B genomes and reduced in the D genome. Within a genome, diversity was diminished on some chromosomes. Low diversity was always accompanied by an excess of rare alleles. A total of 5,471 SNPs was discovered in 1791 wheat genes. Totals of 1,271, 1,218, and 2,203 SNPs were discovered in 488, 463, and 641 genes of wheat putative diploid ancestors, T. urartu, Aegilops speltoides, and Ae. tauschii, respectively. A public database containing genome-specific primers, SNPs, and other information was constructed. A total of 987 genes with nucleotide diversity estimated in one or more of the wheat genomes was placed on an Ae. tauschii genetic map, and the map was superimposed on wheat deletion-bin maps. The agreement between the maps was assessed. Conclusions In a young polyploid, exemplified by T. aestivum, ancestral species are the primary source of genetic diversity. Low effective recombination due to self-pollination and a genetic mechanism precluding homoeologous chromosome pairing during polyploid meiosis can lead to the loss of diversity from large chromosomal regions. The net effect of these factors in T. aestivum is large variation in diversity among genomes and chromosomes, which impacts the development of SNP markers and their practical utility. Accumulation of new mutations in older polyploid species, such as wild emmer, results in increased diversity and its more uniform distribution across the genome.

2010-01-01

98

Lr34 multi-pathogen resistance ABC transporter: molecular analysis of homoeologous and orthologous genes in hexaploid wheat and other grass species.  

PubMed

The Triticum aestivum (bread wheat) disease resistance gene Lr34 confers durable, race non-specific protection against three fungal pathogens, and has been a highly relevant gene for wheat breeding since the green revolution. Lr34, located on chromosome 7D, encodes an ATP-binding cassette (ABC) transporter. Both wheat cultivars with and without Lr34-based resistance encode a putatively functional protein that differ by only two amino acid polymorphisms. In this study, we focused on the identification and characterization of homoeologous and orthologous Lr34 genes in hexaploid wheat and other grasses. In hexaploid wheat we found an expressed and putatively functional Lr34 homoeolog located on chromosome 4A, designated Lr34-B. Another homoeologous Lr34 copy, located on chromosome 7A, was disrupted by the insertion of repetitive elements. Protein sequences of LR34-B and LR34 were 97% identical. Orthologous Lr34 genes were detected in the genomes of Oryza sativa (rice) and Sorghum bicolor (sorghum). Zea mays (maize), Brachypodium distachyon and Hordeum vulgare (barley) lacked Lr34 orthologs, indicating independent deletion of this particular ABC transporter. Lr34 was part of a gene-rich island on the wheat D genome. We found gene colinearity on the homoeologous A and B genomes of hexaploid wheat, but little microcolinearity in other grasses. The homoeologous LR34-B protein and the orthologs from rice and sorghum have the susceptible haplotype for the two critical polymorphisms distinguishing the LR34 proteins from susceptible and resistant wheat cultivars. We conclude that the particular Lr34-haplotype found in resistant wheat cultivars is unique. It probably resulted from functional gene diversification that occurred after the polyploidization event that was at the origin of cultivated bread wheat. PMID:21265893

Krattinger, Simon G; Lagudah, Evans S; Wicker, Thomas; Risk, Joanna M; Ashton, Anthony R; Selter, Liselotte L; Matsumoto, Takashi; Keller, Beat

2010-12-30

99

The wheat chloroplastic proteome.  

PubMed

With the availability of plant genome sequencing, analysis of plant proteins with mass spectrometry has become promising and admired. Determining the proteome of a cell is still a challenging assignment, which is convoluted by proteome dynamics and convolution. Chloroplast is fastidious curiosity for plant biologists due to their intricate biochemical pathways for indispensable metabolite functions. In this review, an overview on proteomic studies conducted in wheat with a special focus on subcellular proteomics of chloroplast, salt and water stress. In recent years, we and other groups have attempted to understand the photosynthesis in wheat and abiotic stress under salt imposed and water deficit during vegetative stage. Those studies provide interesting results leading to better understanding of the photosynthesis and identifying the stress-responsive proteins. Indeed, recent studies aimed at resolving the photosynthesis pathway in wheat. Proteomic analysis combining two complementary approaches such as 2-DE and shotgun methods couple to high through put mass spectrometry (LTQ-FTICR and MALDI-TOF/TOF) in order to better understand the responsible proteins in photosynthesis and abiotic stress (salt and water) in wheat chloroplast will be focused. BIOLOGICAL SIGNIFICANCE: In this review we discussed the identification of the most abundant protein in wheat chloroplast and stress-responsive under salt and water stress in chloroplast of wheat seedlings, thus providing the proteomic view of the events during the development of this seedling under stress conditions. Chloroplast is fastidious curiosity for plant biologists due to their intricate biochemical pathways for indispensable metabolite functions. An overview on proteomic studies conducted in wheat with a special focus on subcellular proteomics of chloroplast, salt and water stress. We have attempted to understand the photosynthesis in wheat and abiotic stress under salt imposed and water deficit during seedling stage. Those studies provide interesting results leading to a better understanding of the photosynthesis and identifying the stress-responsive proteins. In reality, our studies aspired at resolving the photosynthesis pathway in wheat. Proteomic analysis united two complementary approaches such as Tricine SDS-PAGE and 2-DE methods couple to high through put mass spectrometry (LTQ-FTICR and MALDI-TOF/TOF) in order to better understand the responsible proteins in photosynthesis and abiotic stress (salt and water) in wheat chloroplast will be highlighted. This article is part of a Special Issue entitled: Translational Plant Proteomics. PMID:23563086

Kamal, Abu Hena Mostafa; Cho, Kun; Choi, Jong-Soon; Bae, Kwang-Hee; Komatsu, Setsuko; Uozumi, Nobuyuki; Woo, Sun Hee

2013-04-01

100

Discovery and mapping of single feature polymorphisms in wheat using Affymetrix arrays  

PubMed Central

Background Wheat (Triticum aestivum L.) is a staple food crop worldwide. The wheat genome has not yet been sequenced due to its huge genome size (~17,000 Mb) and high levels of repetitive sequences; the whole genome sequence may not be expected in the near future. Available linkage maps have low marker density due to limitation in available markers; therefore new technologies that detect genome-wide polymorphisms are still needed to discover a large number of new markers for construction of high-resolution maps. A high-resolution map is a critical tool for gene isolation, molecular breeding and genomic research. Single feature polymorphism (SFP) is a new microarray-based type of marker that is detected by hybridization of DNA or cRNA to oligonucleotide probes. This study was conducted to explore the feasibility of using the Affymetrix GeneChip to discover and map SFPs in the large hexaploid wheat genome. Results Six wheat varieties of diverse origins (Ning 7840, Clark, Jagger, Encruzilhada, Chinese Spring, and Opata 85) were analyzed for significant probe by variety interactions and 396 probe sets with SFPs were identified. A subset of 164 unigenes was sequenced and 54% showed polymorphism within probes. Microarray analysis of 71 recombinant inbred lines from the cross Ning 7840/Clark identified 955 SFPs and 877 of them were mapped together with 269 simple sequence repeat markers. The SFPs were randomly distributed within a chromosome but were unevenly distributed among different genomes. The B genome had the most SFPs, and the D genome had the least. Map positions of a selected set of SFPs were validated by mapping single nucleotide polymorphism using SNaPshot and comparing with expressed sequence tags mapping data. Conclusion The Affymetrix array is a cost-effective platform for SFP discovery and SFP mapping in wheat. The new high-density map constructed in this study will be a useful tool for genetic and genomic research in wheat.

Bernardo, Amy N; Bradbury, Peter J; Ma, Hongxiang; Hu, Shengwa; Bowden, Robert L; Buckler, Edward S; Bai, Guihua

2009-01-01

101

Identification and validation of a major quantitative trait locus for slow-rusting resistance to stripe rust in wheat.  

PubMed

Stripe (yellow) rust, caused by Puccinia striiformis Westend. f. sp. tritici Eriks (Pst), is one of the most important wheat (Triticum aestivum L.) diseases and causes significant yield losses. A recombinant inbred (RI) population derived from a cross between Yanzhan 1 and Xichang 76-9 cultivars was evaluated for resistance to wheat stripe rust strain CYR32 at both the seedling and adult plant stages. Four resistance quantitative trait loci (QTLs) were detected in this population, in which the major one, designated as Yrq1, was mapped on chromosome 2DS. The strategy of using the Brachypodium distachyon genome, wheat expressed sequence tags and a draft DNA sequences (scaffolds) of the D-genome (Aegilops tauschii Coss.) for the development of simple sequence repeat (SSR) markers was successfully used to identify 147 SSRs in hexaploid wheat. Of the 19 polymorphic SSRs in the RI population, 17 SSRs were mapped in the homeologous group 2 chromosomes near Yrq1 region and eight SSRs were genetically mapped in the 2.7 cM region of Yrq1, providing abundant DNA markers for fine-mapping of Yrq1 and marker-assisted selection in wheat breeding program. The effectiveness of Yrq1 was validated in an independent population, indicating that this resistance QTL can be successfully transferred into a susceptible cultivar for improvement of stripe rust resistance. PMID:22349012

Cao, Xiaohua; Zhou, Jianghong; Gong, Xiaoping; Zhao, Guangyao; Jia, Jizeng; Qi, Xiaoquan

2012-05-01

102

Genetic diversity of wheat storage proteins and bread wheat quality  

Microsoft Academic Search

To understand the genetic and biochemical basis of the bread makingquality of wheat varieties, a large experiment was carried out with a set of162 hexaploid bread wheat varieties registered in the French or EuropeanWheat Catalogue. This material was used to analyse their allelic compositionat the twelve main storage protein loci. A large genetic and biochemicaldiversity of the gluten proteins was

G. Branlard; M. Dardevet; R. Saccomano; F. Lagoutte; J. Gourdon

2001-01-01

103

New Uses for Wheat and Modified Wheat Products  

Technology Transfer Automated Retrieval System (TEKTRAN)

Hard wheat from the Great Plains historically has been used as a source of flour for the production of leavened bakery products. However, potentially applications of wheat in both new markets and new products has necessitated the need to develop wheats with novel processing attributes. The most lo...

104

Russian winter wheat mosaic virus  

Technology Transfer Automated Retrieval System (TEKTRAN)

The chapter contains a description of the Winter wheat (Russian) mosaic disease symptoms, transmission and occurrence. Characteristics of the disease agent, Winter wheat (Russian) mosaic virus are outlined, as are control measures....

105

Recent Advances in Wheat Allelopathy  

Microsoft Academic Search

Wheat (Triticum aestivum), as one of the world’s important crops, has been studied in depth for its allelopathic potential in weed management. Research\\u000a on wheat allelopathy has progressed rapidly from the initial evaluation of allelopathic potential to the identification of\\u000a allelochemicals and genetic markers associated with wheat allelopathy. Allelopathic activity varied among wheat accessions.\\u000a Significant varietal differences in the production

Hanwen Wu; Min An; De Li Liu; Jim Pratley; Deirdre Lemerle

106

Occurrence of trichothecin in wheat.  

PubMed

Trichothecin, a toxic metabolite of Trichothecium roseum, was detected in 3 of 13 wheat samples examined at levels of 560, 290, and 270 ng/g. In addition, all the T. roseum isolates from the wheat produced the toxin on wheat. PMID:16347131

Ishii, K; Kobayashi, J; Ueno, Y; Ichinoe, M

1986-08-01

107

Endothelial progenitor cells in atherosclerosis  

PubMed Central

Endothelial progenitor cells (EPCs) are involved in the maintenance of endothelial homoeostasis and in the process of new vessel formation. Experimental and clinical studies have shown that atherosclerosis is associated with reduced numbers and dysfunction of EPCs; and that medications alone are able to partially reverse the impairment of EPCs in patients with atherosclerosis. Therefore, novel EPC-based therapies may provide enhancement in restoring EPCs’ population and improvement of vascular function. Here, for a better understanding of the molecular mechanisms underlying EPC impairment in atherosclerosis, we provide a comprehensive overview on EPC characteristics, phenotypes, and the signaling pathways underlying EPC impairment in atherosclerosis.

Du, Fuyong; Zhou, Jun; Gong, Ren; Huang, Xiao; Pansuria, Meghana; Virtue, Anthony; Li, Xinyuan; Wang, Hong; Yang, Xiao-Feng

2012-01-01

108

Double Degenerate Progenitors of Supernovae Type IA  

Microsoft Academic Search

While supernovae Ia (SNe Ia) play a prominent role in extragalactic astronomy the nature of their progenitors is still unknown. In one of the two viable progenitor scenarios SN Ia result from the merging of a binary consisting of two white dwarfs (double degenerates - DDs) exceeding the Chandrasekhar mass limit. I'll review the results of recent radial velocity surveys

Ralf Napiwotzki

2003-01-01

109

Neural progenitors from human embryonic stem cells  

Microsoft Academic Search

The derivation of neural progenitor cells from human embryonic stem (ES) cells is of value both in the study of early human neurogenesis and in the creation of an unlimited source of donor cells for neural transplantation therapy. Here we report the generation of enriched and expandable preparations of proliferating neural prog- enitors from human ES cells. The neural progenitors

Benjamin E. Reubinoff; Pavel Itsykson; Tikva Turetsky; Martin F. Pera; Etti Reinhartz; Anna Itzik; Tamir Ben-Hur

2000-01-01

110

The endocannabinoid system drives neural progenitor proliferation  

Microsoft Academic Search

The discovery of multipotent neural progenitor (NP) cells has provided strong support for the existence of neurogenesis in the adult brain. However, the signals controlling NP proliferation remain elusive. Endocannabinoids, the endogenous counterparts of marijuana-derived cannabinoids, act as neuromodulators via presynaptic CB1 receptors and also control neural cell death and survival. Here we show that progenitor cells express a functional

Tania Aguado; Krisztina Monory; Javier Palazuelos; Nephi Stella; Benjamin Cravatt; Beat Lutz; Giovanni Marsicano; Zaal Kokaia; Manuel Guzmán; Ismael Galve-Roperh

2005-01-01

111

Inheritance of Russian wheat aphid resistance from tetraploid wheat accessions during transfer to hexaploid wheat  

Microsoft Academic Search

Identification of new sources of resistance to Russian wheat aphid (RWA) (Diuraphis noxia (Kurdjumov) in wheat (Triticum aestivum L.) has become very important with the identification of several new biotypes since 2003. Our objective was to characterize\\u000a inheritance and expression of resistance to RWA biotype 2 from three tetraploid wheat landraces (Triticum turgidum L. subsp. dicoccon) during transfer to hexaploid

Benjamin M. Beyer; Scott D. Haley; Nora L. V. Lapitan; Junhua H. Peng; Frank B. Peairs

2011-01-01

112

A Whole-Genome DNA Marker Map for Cotton Based on the D-Genome Sequence of Gossypium raimondii L.  

PubMed Central

We constructed a very-high-density, whole-genome marker map (WGMM) for cotton by using 18,597 DNA markers corresponding to 48,958 loci that were aligned to both a consensus genetic map and a reference genome sequence. The WGMM has a density of one locus per 15.6 kb, or an average of 1.3 loci per gene. The WGMM was anchored by the use of colinear markers to a detailed genetic map, providing recombinational information. Mapped markers occurred at relatively greater physical densities in distal chromosomal regions and lower physical densities in the central regions, with all 1 Mb bins having at least nine markers. Hotspots for quantitative trait loci and resistance gene analog clusters were aligned to the map and DNA markers identified for targeting of these regions of high practical importance. Based on the cotton D genome reference sequence, the locations of chromosome structural rearrangements plotted on the map facilitate its translation to other Gossypium genome types. The WGMM is a versatile genetic map for marker assisted breeding, fine mapping and cloning of genes and quantitative trait loci, developing new genetic markers and maps, genome-wide association mapping, and genome evolution studies.

Wang, Zining; Zhang, Dong; Wang, Xiyin; Tan, Xu; Guo, Hui; Paterson, Andrew H.

2013-01-01

113

A Whole-Genome DNA Marker Map for Cotton Based on the D-Genome Sequence of Gossypium raimondii L.  

PubMed

We constructed a very-high-density, whole-genome marker map (WGMM) for cotton by using 18,597 DNA markers corresponding to 48,958 loci that were aligned to both a consensus genetic map and a reference genome sequence. The WGMM has a density of one locus per 15.6 kb, or an average of 1.3 loci per gene. The WGMM was anchored by the use of colinear markers to a detailed genetic map, providing recombinational information. Mapped markers occurred at relatively greater physical densities in distal chromosomal regions and lower physical densities in the central regions, with all 1 Mb bins having at least nine markers. Hotspots for quantitative trait loci and resistance gene analog clusters were aligned to the map and DNA markers identified for targeting of these regions of high practical importance. Based on the cotton D genome reference sequence, the locations of chromosome structural rearrangements plotted on the map facilitate its translation to other Gossypium genome types. The WGMM is a versatile genetic map for marker assisted breeding, fine mapping and cloning of genes and quantitative trait loci, developing new genetic markers and maps, genome-wide association mapping, and genome evolution studies. PMID:23979945

Wang, Zining; Zhang, Dong; Wang, Xiyin; Tan, Xu; Guo, Hui; Paterson, Andrew H

2013-10-03

114

Progenitor cells in infantile hemangioma  

PubMed Central

Infantile hemangioma is a vascular tumor that occurs in 5–10% of infants of European descent. A hallmark of infantile hemangioma is its lifecycle, which is divided into three stages. The proliferating phase spans the first year of postnatal life, and is characterized by cellular masses without a defined vascular architecture as well as nascent blood vessels with red blood cells evident within the lumenal space. The involuting phase begins around one year of age and continues for 3–5 years. Proliferation slows or stops in this phase, and histology shows that the blood vessel architecture becomes more obvious and vessel size is enlarged. The involuted phase is reached by 5–8 years of age, at which point blood vessels are replaced with a fibrofatty residuum and capillary-sized channels. The growth and involution life-cycle of infantile hemangioma is very different from other vascular tumors and vascular malformations, which do not regress and can occur at any time during childhood or adult life. Many laboratories have reported on the endothelial characteristics of the cellular masses that are prominent in the proliferating phase of infantile hemangioma, as well as their immature appearance. These studies, along with isolation and characterization of hemangioma-derived cell populations with progenitor cell properties have lead to an emerging hypothesis that hemangioma is caused by an abnormal or delayed differentiation of mesodermal progenitor cells into the disorganized mass of blood vessels. Here we discuss the literature that support this emerging hypothesis.

Bischoff, Joyce

2010-01-01

115

Biolistics Transformation of Wheat  

NASA Astrophysics Data System (ADS)

We present a complete, step-by-step guide to the production of transformed wheat plants using a particle bombardment device to deliver plasmid DNA into immature embryos and the regeneration of transgenic plants via somatic embryogenesis. Currently, this is the most commonly used method for transforming wheat and it offers some advantages. However, it will be interesting to see whether this position is challenged as facile methods are developed for delivering DNA by Agrobacterium tumefaciens or by the production of transformants via a germ-line process (see other chapters in this book).

Sparks, Caroline A.; Jones, Huw D.

116

Haplotype variation of glu-d1 locus and the origin of glu-d1d allele conferring superior end-use qualities in common wheat.  

PubMed

In higher plants, seed storage proteins (SSPs) are frequently expressed from complex gene families, and allelic variation of SSP genes often affects the quality traits of crops. In common wheat, the Glu-D1 locus, encoding 1Dx and 1Dy SSPs, has multiple alleles. The Glu-D1d allele frequently confers superior end-use qualities to commercial wheat varieties. Here, we studied the haplotype structure of Glu-D1 genomic region and the origin of Glu-D1d. Using seven diagnostic DNA markers, 12 Glu-D1 haplotypes were detected among common wheat, European spelt wheat (T. spelta, a primitive hexaploid relative of common wheat), and Aegilops tauschii (the D genome donor of hexaploid wheat). By comparatively analyzing Glu-D1 haplotypes and their associated 1Dx and 1Dy genes, we deduce that the haplotype carrying Glu-D1d was likely differentiated in the ancestral hexaploid wheat around 10,000 years ago, and was subsequently transmitted to domesticated common wheat and T. spelta. A group of relatively ancient Glu-D1 haplotypes was discovered in Ae. tauschii, which may serve for the evolution of other haplotypes. Moreover, a number of new Glu-D1d variants were found in T. spelta. The main steps in Glu-D1d differentiation are proposed. The implications of our work for enhancing the utility of Glu-D1d in wheat quality improvement and studying the SSP alleles in other crop species are discussed. PMID:24098671

Dong, Zhenying; Yang, Yushuang; Li, Yiwen; Zhang, Kunpu; Lou, Haijuan; An, Xueli; Dong, Lingli; Gu, Yong Qiang; Anderson, Olin D; Liu, Xin; Qin, Huanju; Wang, Daowen

2013-09-30

117

Haplotype Variation of Glu-D1 Locus and the Origin of Glu-D1d Allele Conferring Superior End-Use Qualities in Common Wheat  

PubMed Central

In higher plants, seed storage proteins (SSPs) are frequently expressed from complex gene families, and allelic variation of SSP genes often affects the quality traits of crops. In common wheat, the Glu-D1 locus, encoding 1Dx and 1Dy SSPs, has multiple alleles. The Glu-D1d allele frequently confers superior end-use qualities to commercial wheat varieties. Here, we studied the haplotype structure of Glu-D1 genomic region and the origin of Glu-D1d. Using seven diagnostic DNA markers, 12 Glu-D1 haplotypes were detected among common wheat, European spelt wheat (T. spelta, a primitive hexaploid relative of common wheat), and Aegilops tauschii (the D genome donor of hexaploid wheat). By comparatively analyzing Glu-D1 haplotypes and their associated 1Dx and 1Dy genes, we deduce that the haplotype carrying Glu-D1d was likely differentiated in the ancestral hexaploid wheat around 10,000 years ago, and was subsequently transmitted to domesticated common wheat and T. spelta. A group of relatively ancient Glu-D1 haplotypes was discovered in Ae. tauschii, which may serve for the evolution of other haplotypes. Moreover, a number of new Glu-D1d variants were found in T. spelta. The main steps in Glu-D1d differentiation are proposed. The implications of our work for enhancing the utility of Glu-D1d in wheat quality improvement and studying the SSP alleles in other crop species are discussed.

Li, Yiwen; Zhang, Kunpu; Lou, Haijuan; An, Xueli; Dong, Lingli; Gu, Yong Qiang; Anderson, Olin D.; Liu, Xin; Qin, Huanju; Wang, Daowen

2013-01-01

118

[Reviewed on wheat genome].  

PubMed

Research development of genetic mapping,physics mapping,genome sequencing and expressed sequence tags in wheat have been reviewed in this paper. RFLP genetic linkage map of wheat recombinant inbred lines derived from W7984 x Opata, was used to study QTL of 33 traits associated with water use efficiency. Compared with QTL map of 7 group homeologues chromosomes, the results were showed as follows: nearby the centromeric region of 1A and 1B chromosome, the gene cluster of controlling photosynthetic and root traits were located. The gene clusters of controlling water use efficiency per plant,root and plant height and growth rate were located on the 2 group chromosomes. The gene clusters of controlling root traits were located on the 6A an 6B chromosome, there was a big gene cluster mad up by 7 QTLs controlling water use efficiency of wheat leaf and per plant nearby the centromeric region of 6D chromosome. It showed that 6th homologous chromosomes play an important role in controlling water use efficiency in wheat. PMID:16126710

Zhang, Zheng-Bin; Xu, Ping

2002-05-01

119

Drought resistance in wheat  

Microsoft Academic Search

Summary 1.The general trend of various factors in the leaves of the wheat varieties Currawa, Federation and Major, respectively, has been followed throughout the season of the year 1933.2.The factors observed included the water content of the leaves, the sap expressed from the leaves under pressure, the water content of the pressed leaves, the total, free and bound water and

J. Calvert

1935-01-01

120

Registration of ‘Shirley’ Wheat  

Technology Transfer Automated Retrieval System (TEKTRAN)

‘Shirley’ (Reg. No. CV-, PI) soft red winter (SRW) wheat (Triticum aestivum L.) was developed by the Virginia Agricultural Experiment Station and released in March 2008. Shirley was derived from the three-way cross VA94-52-25 / ‘Coker 9835’ (PI 548846 PVPO) // VA96-54-234. Shirley is widely adapted ...

121

Registration of ‘Jamestown’ Wheat  

Technology Transfer Automated Retrieval System (TEKTRAN)

‘Jamestown’ (Reg. No. CV-, PI 653731) soft red winter wheat (Triticum aestivum L.) was developed and released by the Virginia Agricultural Experiment Station in March 2007. Jamestown was derived from the cross ‘Roane’ (PI 612958)/Pioneer Brand ‘2691’ (PI 590941 PVPO) and was tested under the experim...

122

Registration of ‘5205’ Wheat  

Technology Transfer Automated Retrieval System (TEKTRAN)

The soft red winter (SRW) wheat (Triticum aestivum L.) cultivar ‘5205’ (Reg. No. CV-, PI) was developed by the Virginia Agricultural Experiment Station and released in March 2008. Cultivar 5205 was derived from the three-way cross Pioneer Brand ‘2684’ (PI 566923 PVPO) / VA93-54-185 // ’Pocahontas’ ...

123

Registration of 'Juniper' Wheat  

Technology Transfer Automated Retrieval System (TEKTRAN)

‘Juniper’ (PI 639951) is a hard red winter wheat (Triticum aestivum L.) developed by the Idaho Agricultural Experimental Station and released in February 2006. Juniper, named for the town of Juniper, Idaho, was released for its superior yield and quality compared with previous full stature hard red...

124

REGISTRATION OF 'DELIVER' WHEAT  

Technology Transfer Automated Retrieval System (TEKTRAN)

‘Deliver’ (Reg. No. CV-_______, PI 639232) hard red winter wheat (Triticum aestivum L.) was released to certified seed growers with permission of the Oklahoma Agricultural Experiment Station (AES) and the USDA-ARS in 2004. Deliver, an awnletted cultivar, was named for its unique and competitive abil...

125

Registration of Camelot Wheat  

Technology Transfer Automated Retrieval System (TEKTRAN)

'Camelot ' (PI 653832) hard red winter wheat (Triticum aestivum L.) was developed cooperatively by the Nebraska Agricultural Experiment Station and the USDA-ARS and released in 2008. In addition to researchers at the releasing institutions, USDA-ARS researchers at Manhattan, KS, and St. Paul, MN, ...

126

Modelling Wheat Production  

Technology Transfer Automated Retrieval System (TEKTRAN)

In wheat, a shorter pre-anthesis phase is often associated with increased grain protein content (GPC) but decreased grain yield. Cultivar differences in pre-anthesis development are mainly determined by vernalization requirement, photoperiod sensitivity and earliness per se. This research examines w...

127

REGISTRATION OF 'MACON' WHEAT  

Technology Transfer Automated Retrieval System (TEKTRAN)

'Macon' hard white spring wheat (Triticum aestivum L.) (Reg. no. CV-PI 617072) was developed by the Agricultural Research Center of Washington State University in cooperation with the Agricultural Experiment Stations (AESs) of the University of Idaho and Oregon State University, and the United State...

128

Registration of ‘Endurance’ Wheat  

Technology Transfer Automated Retrieval System (TEKTRAN)

‘Endurance’ (Reg. No. CV-994, PI 639233) hard red winter wheat (Triticum aestivum L.) was released to certified seed growers with permission of the Oklahoma Agricultural Experiment Station and the USDA-ARS in 2004. Its name derives from the unique ability to endure and recover from extended and inte...

129

REGISTRATION OF 'EDNURANCE' WHEAT  

Technology Transfer Automated Retrieval System (TEKTRAN)

‘Endurance’ is a hard red winter wheat (Triticum aestivum L.) that was released to certified seed growers with permission of the Oklahoma Agricultural Experiment Station and the USDA-ARS in 2004. Its name derives from the unique ability to endure and recover from extended and intensive grazing in a...

130

REGISTRATION OF 'INTRADA' WHEAT  

Technology Transfer Automated Retrieval System (TEKTRAN)

'Intrada' is a hard white winter wheat (Triticum aestivum L.) developed cooperatively by the Oklahoma Agricultural Experiment Station, Kansas Agricultural Experiment Station, and the USDA-ARS, and released in September, 2000, in cooperation with the USDA-ARS. Intrada was released for its high yield...

131

The interface between glial progenitors and gliomas  

PubMed Central

The mammalian brain and spinal cord contain heterogeneous populations of cycling, immature cells. These include cells with stem cell-like properties as well as progenitors in various stages of early glial differentiation. This latter population is distributed widely throughout gray and white matter and numerically represents an extremely large cell pool. In this review, we discuss the possibility that the glial progenitors that populate the adult CNS are one source of gliomas. Indeed, the marker phenotypes, morphologies, and migratory properties of cells in gliomas strongly resemble glial progenitors in many ways. We review briefly some salient features of normal glial development and then examine the similarities and differences between normal progenitors and cells in gliomas, focusing on the phenotypic plasticity of glial progenitors and the responses to growth factors in promoting proliferation and migration of normal and glioma cells, and discussing known mutational changes in gliomas in the context of how these might affect the proliferative and migratory behaviors of progenitors. Finally, we will discuss the “cancer stem cell” hypothesis in light of the possibility that glial progenitors can generate gliomas.

Canoll, Peter

2009-01-01

132

Stem cells and progenitor cells in renal disease  

Microsoft Academic Search

Stem cells and progenitor cells in renal tissue. Stem cells and progenitor cells are necessary for repair and regeneration of injured renal tissue. Infiltrating or resident stem cells can contribute to the replacement of lost or damaged tissue. However, the regulation of circulating progenitor cells is not well understood. We have analyzed the effects of erythropoietin on circulating progenitor cells

HERMANN HALLER; KIRSTEN DE GROOT; FERDINAND BAHLMANN; MARLIES ELGER; DANILO FLISER

2005-01-01

133

Low temperature-induced necrosis shows phenotypic plasticity in wheat triploid hybrids.  

PubMed

Hybrid necrosis sometimes appears in triploid hybrids between tetraploid wheat and Aegilops tauschii Coss. Two types of hybrid necrosis (type II and type III) were observed when cultivar Langdon was used as female parent for hybrid production. Type II necrosis symptoms occurred only under low temperature conditions, whereas bushy and dwarf phenotypes were observed under normal temperature conditions. The developmental plasticity might be related to a temperature-responsive alteration of meristematic activity at the crown tissue of triploid hybrids. Epistatic interaction between the AB and D genomes induced not only upregulation of a number of defense-related genes, but also extensive changes in plant architecture in the type II necrosis hybrids. Such phenotypic plasticity was also observed in other cross combinations between cultivated tetraploid wheat and type II necrosis-induced Ae. tauschii accessions. Wild tetraploid wheat, Triticum turgidum subspecies dicoccoides, did not induce type II necrosis in the triploid hybrids, indicating the possibility of identifying the chromosomal location of a causal gene for type II necrosis in the AB genome. PMID:21897130

Takumi, Shigeo; Mizuno, Nobuyuki

2011-10-01

134

Wheat CBF gene family: identification of polymorphisms in the CBF coding sequence.  

PubMed

Expression of cold-regulated genes needed for protection against freezing stress is mediated, in part, by the CBF transcription factor family. Previous studies with temperate cereals suggested that the CBF gene family in wheat was large, and that CBF genes were at the base of an important low temperature tolerance trait. Therefore, the goal of our study was to identify the CBF repertoire in the freezing-tolerant hexaploid wheat cultivar Norstar, and then to examine if the coding region of CBF genes in two spring cultivars contain polymorphisms that could affect the protein sequence and structure. Our analyses reveal that hexaploid wheat contains a complex CBF family consisting of at least 65 CBF genes of which 60 are known to be expressed in the cultivar Norstar. They represent 27 paralogous genes with 1-3 homeologous copies for the A, B, and D genomes. The cultivar Norstar contains two pseudogenes and at least 24 additional proteins having sequences and (or) structures that deviate from the consensus in the conserved AP2 DNA-binding and (or) C-terminal activation-domains. This suggests that in cultivars such as Norstar, low temperature tolerance may be increased through breeding of additional optimal alleles. The examination of the CBF repertoire present in the two spring cultivars, Chinese Spring and Manitou, reveals that they have additional polymorphisms affecting conserved positions in these domains. Understanding the effects of these polymorphisms will provide additional information for the selection of optimum CBF alleles in Triticeae breeding programs. PMID:23231605

Mohseni, Sara; Che, Hua; Djillali, Zakia; Dumont, Estelle; Nankeu, Joseph; Danyluk, Jean

2012-12-05

135

Progenitor's Signatures in Type Ia Supernova Remnants  

NASA Astrophysics Data System (ADS)

The remnants of Type Ia supernovae (SNe Ia) can provide important clues about their progenitor histories. We discuss two well-observed supernova remnants (SNRs) that are believed to have resulted from SNe Ia, and use various tools to shed light on the possible progenitor histories. We find that Kepler's SNR is consistent with a symbiotic binary progenitor consisting of a white dwarf and an AGB star. Our hydrosimulations can reproduce the observed kinematic and morphological properties. For Tycho's remnant we use the characteristics of the X-ray spectrum and kinematics to show that the ejecta has likely interacted with dense circumstellar gas.

Chiotellis, A.; Kosenko, D.; Schure, K. M.; Vink, J.

2013-01-01

136

PCR identification of durum wheat BAC clones containing genes coding for carotenoid biosynthesis enzymes and their chromosome localization.  

PubMed

Carotenoids are essential components in all plants. Their accumulation in wheat seed determines the endosperm colour, which is an important quality trait in wheat. In this study, we report the isolation of BAC clones containing genes coding for three different enzymes of the carotenoid biosynthesis pathway: phytoene synthase (PSY), phytoene desaturase (PDS), and zeta-carotene desaturase (ZDS). Primers were designed on the basis of wheat ESTs similar to the sequences of these three genes in other species, and used to screen a BAC library from Triticum turgidum var. durum (2n = 28, genomes AABB). Eight, six, and nine 384-well plates containing at least one positive clone were found for PSY, PDS, and ZDS, respectively. BACs selected for each of these genes were then divided in two groups corresponding to the A and B genomes of tetraploid wheat, based on differences in the length of the PCR amplification products, conformation-sensitive gel electrophoresis (CSGE), or cleavage amplification polymorphisms. Positive clones were then assigned to chromosomes using a set of D genome substitution lines in T. turgidum var. durum 'Langdon'. PSY clones were localized on chromosomes 5A and 5B, PDS on chromosomes 4A and 4B, and ZDS on chromosomes 2A and 2B. The strategies used for the PCR screening of large BAC libraries and for the differentiation of BAC clones from different genomes in a polyploid species are discussed. PMID:15499405

Cenci, A; Somma, S; Chantret, N; Dubcovsky, J; Blanco, A

2004-10-01

137

Chromaffin Progenitor Cells from the Adrenal Medulla  

Microsoft Academic Search

Chromaffin cells of the adrenal medulla are neural crest-derived cells of the sympathoadrenal lineage. Different lines of\\u000a evidence suggest the existence of a subpopulation of proliferation-competent progenitor cells even in the adult state. The\\u000a identification of sympathoadrenal progenitors in the adrenal would greatly enhance the understanding of adrenal physiology\\u000a and their potential role in adrenal pathogenesis. Isolation and differentiation of

Monika Ehrhart-Bornstein; Vladimir Vukicevic; Kuei-Fang Chung; Mushfika Ahmad; Stefan R. Bornstein

2010-01-01

138

Genetic Regulation of Thymocyte Progenitor Aging  

PubMed Central

The number of T cell progenitors is significantly reduced in the involuted thymus, and the growth and developmental potential of the few cells that are present is severely attenuated. This review provides an overview of how aging affects T cell precursors before and following entry into the thymus and discusses the age related genetic changes that may occur in them. Finally, interventions that rejuvenate thymopoiesis in the elderly by targeting T cell progenitors are discussed.

Berent-Maoz, Beata; Montecino-Rodriguez, Encarnacion; Dorshkind, Kenneth

2012-01-01

139

X Inactivation and Progenitor Cancer Cells  

PubMed Central

In mammals, silencing of one of the two X chromosomes is necessary to achieve dosage compensation. The 17 kb non-coding RNA called Xist triggers X inactivation. Gene silencing by Xist can only be achieved in certain contexts such as in cells of the early embryo and in certain hematopoietic progenitors where silencing factors are present. Moreover, these epigenetic contexts are maintained in cancer progenitors in which SATB1 has been identified as a factor related to Xist-mediated chromosome silencing.

Agrelo, Ruben

2011-01-01

140

Progenitor cells in pulmonary vascular remodeling  

PubMed Central

Pulmonary hypertension is characterized by cellular and structural changes in the walls of pulmonary arteries. Intimal thickening and fibrosis, medial hypertrophy and fibroproliferative changes in the adventitia are commonly observed, as is the extension of smooth muscle into the previously non-muscularized vessels. A majority of these changes are associated with the enhanced presence of ?-SM-actin+ cells and inflammatory cells. Atypical abundances of functionally distinct endothelial cells, particularly in the intima (plexiform lesions), and also in the perivascular regions, are also described. At present, neither the origin(s) of these cells nor the molecular mechanisms responsible for their accumulation, in any of the three compartments of the vessel wall, have been fully elucidated. The possibility that they arise from either resident vascular progenitors or bone marrow–derived progenitor cells is now well established. Resident vascular progenitor cells have been demonstrated to exist within the vessel wall, and in response to certain stimuli, to expand and express myofibroblastic, endothelial or even hematopoietic markers. Bone marrow–derived or circulating progenitor cells have also been shown to be recruited to sites of vascular injury and to assume both endothelial and SM-like phenotypes. Here, we review the data supporting the contributory role of vascular progenitors (including endothelial progenitor cells, smooth muscle progenitor cells, pericytes, and fibrocytes) in vascular remodeling. A more complete understanding of the processes by which progenitor cells modulate pulmonary vascular remodeling will undoubtedly herald a renaissance of therapies extending beyond the control of vascular tonicity and reduction of pulmonary artery pressure.

Yeager, Michael E.; Frid, Maria G.; Stenmark, Kurt R.

2011-01-01

141

Origins and Fates of Cardiovascular Progenitor Cells  

PubMed Central

Multipotent cardiac progenitor cells are found in the fetal and adult heart of many mammalian species including humans and form as intermediates during the differentiation of embryonic stem cells. Despite similar biological properties, the molecular identities of these different cardiac progenitor cell populations appear to be distinct. Elucidating the origins and lineage relationships of these cell populations will accelerate clinical applications such as drug screening and cell therapy as well as shedding light on the pathogenic mechanisms underlying cardiac diseases.

Wu, Sean M.; Chien, Kenneth R.; Mummery, Christine

2008-01-01

142

Endothelial progenitor cells in infantile hemangioma  

Microsoft Academic Search

Infantile hemangioma is an endothelial tumor that grows rapidly after birth but slowly regresses during early childhood. Initial proliferation of hemangioma is char- acterized by clonal expansion of endothe- lial cells (ECs) and neovascularization. Here, we demonstrated mRNA encoding CD133-2, an important marker for endo- thelial progenitor cells (EPCs), predomi- nantly in proliferating but not involuting or involuted hemangioma. Progenitor

Ying Yu; Alan F. Flint; John B. Mulliken; June K. Wu; Joyce Bischoff

2010-01-01

143

Genomics of Wheat Domestication  

Microsoft Academic Search

The review covers several issues concerning the state of molecular knowledge of the effects induced by domestication and breeding\\u000a on the wheat crop. Genes at the root of the domestication syndrome are currently the focus of an active research which frequently\\u000a uses comparative genomics approaches. Conclusions drawn on available data indicate that the domestication syndrome is originated\\u000a by “sudden” genetic

Carlo Pozzi; Francesco Salamini

144

Evolution of new disease specificity at a simple resistance locus in a crop-weed complex: reconstitution of the Lr21 gene in wheat.  

PubMed

The wheat leaf-rust resistance gene Lr21 was first identified in an Iranian accession of goatgrass, Aegilops tauschii Coss., the D-genome donor of hexaploid bread wheat, and was introgressed into modern wheat cultivars by breeding. To elucidate the origin of the gene, we analyzed sequences of Lr21 and lr21 alleles from 24 wheat cultivars and 25 accessions of Ae. tauschii collected along the Caspian Sea in Iran and Azerbaijan. Three basic nonfunctional lr21 haplotypes, H1, H2, and H3, were identified. Lr21 was found to be a chimera of H1 and H2, which were found only in wheat. We attempted to reconstitute a functional Lr21 allele by crossing the cultivars Fielder (H1) and Wichita (H2). Rust inoculation of 5876 F(2) progeny revealed a single resistant plant that proved to carry the H1H2 haplotype, a result attributed to intragenic recombination. These findings reflect how plants balance the penalty and the necessity of a resistance gene and suggest that plants can reuse "dead" alleles to generate new disease-resistance specificity, leading to a "death-recycle" model of plant-resistance gene evolution at simple loci. We suggest that selection pressure in crop-weed complexes contributes to this process. PMID:19364806

Huang, Li; Brooks, Steven; Li, Wanlong; Fellers, John; Nelson, James C; Gill, Bikram

2009-04-13

145

Hepatic stellate cell progenitor cells  

PubMed Central

Hepatic stellate cells (HSCs) are recognized as a major player in liver fibrogenesis. Upon liver injury, HSCs differentiate into myofibroblasts and participate in progression of fibrosis and cirrhosis. Additional cell types such as resident liver fibroblasts/myofibroblasts or bone marrow cells are also known to generate myofibroblasts. One of the major obstacles to understanding the mechanism of liver fibrogenesis is the lack of knowledge regarding the developmental origin of HSCs and other liver mesenchymal cells. Recent cell lineage analyses demonstrate that HSCs are derived from mesoderm during liver development. MesP1-expressing mesoderm gives rise to the septum transversum mesenchyme before liver formation and then to the liver mesothelium and mesenchymal cells, including HSCs and perivascular mesenchymal cells around the veins during liver development. During the growth of embryonic liver, the mesothelium, consisting of mesothelial cells and submesothelial cells, migrates inward from the liver surface and gives rise to HSCs and perivascular mesenchymal cells, including portal fibroblasts, smooth muscle cells around the portal vein, and fibroblasts around the central vein. Cell lineage analyses indicate that mesothelial cells are HSC progenitor cells capable of differentiating into HSCs and other liver mesenchymal cells during liver development.

Asahina, Kinji

2011-01-01

146

Endothelial progenitor cells: Quo Vadis?  

PubMed Central

The term endothelial progenitor cell (EPC) was coined to refer to circulating cells that displayed the ability to display cell surface antigens similar to endothelial cells in vitro, to circulate and lodge in areas of ischemia or vascular injury, and to facilitate the repair of damaged blood vessels or augment development of new vessels as needed by a tissue. More than 10 years after the first report, the term EPC is used to refer to a host of circulating cells that display some or all of the qualities indicated above, however, essentially all of the cells are now known to be members of the hematopoietic lineage. The exception is a rare viable circulating endothelial cell with clonal proliferative potential that displays the ability to spontaneously form inosculating human blood vessels upon implantation into immunodeficient murine host tissues. This paper will review the current lineage relationships among all the cells called EPC and will propose that the term EPC be retired and that each of the circulating cell subsets be referred to according to the terms already existent for each subset. This article is part of a special issue entitled, "Cardiovascular Stem Cells Revisited".

Richardson, Matthew R.; Yoder, Mervin C.

2012-01-01

147

Identification and phylogenetic analysis of a CC-NBS-LRR encoding gene assigned on chromosome 7B of wheat.  

PubMed

Hexaploid wheat displays limited genetic variation. As a direct A and B genome donor of hexaploid wheat, tetraploid wheat represents an important gene pool for cultivated bread wheat. Many disease resistant genes express conserved domains of the nucleotide-binding site and leucine-rich repeats (NBS-LRR). In this study, we isolated a CC-NBS-LRR gene locating on chromosome 7B from durum wheat variety Italy 363, and designated it TdRGA-7Ba. Its open reading frame was 4014 bp, encoding a 1337 amino acid protein with a complete NBS domain and 18 LRR repeats, sharing 44.7% identity with the PM3B protein. TdRGA-7Ba expression was continuously seen at low levels and was highest in leaves. TdRGA-7Ba has another allele TdRGA-7Bb with a 4 bp deletion at position +1892 in other cultivars of tetraploid wheat. In Ae. speltoides, as a B genome progenitor, both TdRGA-7Ba and TdRGA-7Bb were detected. In all six species of hexaploid wheats (AABBDD), only TdRGA-7Bb existed. Phylogenic analysis showed that all TdRGA-7Bb type genes were grouped in one sub-branch. We speculate that TdRGA-7Bb was derived from a TdRGA-7Ba mutation, and it happened in Ae. speltoides. Both types of TdRGA-7B participated in tetraploid wheat formation. However, only the TdRGA-7Bb was retained in hexaploid wheat. PMID:23887654

Gong, Caiyan; Cao, Shuanghe; Fan, Renchun; Wei, Bo; Chen, Guiping; Wang, Xianping; Li, Yiwen; Zhang, Xiangqi

2013-07-24

148

Identification and Phylogenetic Analysis of a CC-NBS-LRR Encoding Gene Assigned on Chromosome 7B of Wheat  

PubMed Central

Hexaploid wheat displays limited genetic variation. As a direct A and B genome donor of hexaploid wheat, tetraploid wheat represents an important gene pool for cultivated bread wheat. Many disease resistant genes express conserved domains of the nucleotide-binding site and leucine-rich repeats (NBS-LRR). In this study, we isolated a CC-NBS-LRR gene locating on chromosome 7B from durum wheat variety Italy 363, and designated it TdRGA-7Ba. Its open reading frame was 4014 bp, encoding a 1337 amino acid protein with a complete NBS domain and 18 LRR repeats, sharing 44.7% identity with the PM3B protein. TdRGA-7Ba expression was continuously seen at low levels and was highest in leaves. TdRGA-7Ba has another allele TdRGA-7Bb with a 4 bp deletion at position +1892 in other cultivars of tetraploid wheat. In Ae. speltoides, as a B genome progenitor, both TdRGA-7Ba and TdRGA-7Bb were detected. In all six species of hexaploid wheats (AABBDD), only TdRGA-7Bb existed. Phylogenic analysis showed that all TdRGA-7Bb type genes were grouped in one sub-branch. We speculate that TdRGA-7Bb was derived from a TdRGA-7Ba mutation, and it happened in Ae. speltoides. Both types of TdRGA-7B participated in tetraploid wheat formation. However, only the TdRGA-7Bb was retained in hexaploid wheat.

Gong, Caiyan; Cao, Shuanghe; Fan, Renchun; Wei, Bo; Chen, Guiping; Wang, Xianping; Li, Yiwen; Zhang, Xiangqi

2013-01-01

149

Real time imaging of human progenitor neurogenesis.  

PubMed

Human neural progenitors are increasingly being employed in drug screens and emerging cell therapies targeted towards neurological disorders where neurogenesis is thought to play a key role including developmental disorders, Alzheimer's disease, and depression. Key to the success of these applications is understanding the mechanisms by which neurons arise. Our understanding of development can provide some guidance but since little is known about the specifics of human neural development and the requirement that cultures be expanded in vitro prior to use, it is unclear whether neural progenitors obey the same developmental mechanisms that exist in vivo. In previous studies we have shown that progenitors derived from fetal cortex can be cultured for many weeks in vitro as undifferentiated neurospheres and then induced to undergo neurogenesis by removing mitogens and exposing them to supportive substrates. Here we use live time lapse imaging and immunocytochemical analysis to show that neural progenitors use developmental mechanisms to generate neurons. Cells with morphologies and marker profiles consistent with radial glia and recently described outer radial glia divide asymmetrically and symmetrically to generate multipolar intermediate progenitors, a portion of which express ASCL1. These multipolar intermediate progenitors subsequently divide symmetrically to produce CTIP2(+) neurons. This 3-cell neurogenic scheme echoes observations in rodents in vivo and in human fetal slice cultures in vitro, providing evidence that hNPCs represent a renewable and robust in vitro assay system to explore mechanisms of human neurogenesis without the continual need for fresh primary human fetal tissue. Knowledge provided by this and future explorations of human neural progenitor neurogenesis will help maximize the safety and efficacy of new stem cell therapies by providing an understanding of how to generate physiologically-relevant cell types that maintain their identities when placed in diagnostic or transplantation environments. PMID:20949053

Keenan, Thomas M; Nelson, Aaron D; Grinager, Jeffrey R; Thelen, Jarett C; Svendsen, Clive N

2010-10-07

150

Wheat Stripe Rust in China.  

Technology Transfer Automated Retrieval System (TEKTRAN)

China has the largest epidemic region in the world in terms of wheat acreage affected by stripe rust. Extensive studies on the epidemiology and management were carried out since the widespread occurrence in 1950’s. Based on the factors influencing occurrence of wheat stripe rust, 15 epidemic zones w...

151

A TRANSCRIPTOME MAP OF WHEAT  

Technology Transfer Automated Retrieval System (TEKTRAN)

A transcriptome map of wheat genome with 16,099 EST loci spanning the 21 chromosomes of bread wheat (Triticum aestivum L.) or an average of 766 loci per chromosome, has been developed. Of the 16,099 EST loci, 14,051 were allocated to 159 bins using a set of nullisomic-tetrasomic, ditelosomic, and de...

152

PROTEIN DEMAND IN HARD WHEATS  

Microsoft Academic Search

Wheat protein is one of the most important specifications used in domestic and import purchase contracts. It is used as a proxy for functional quality that is important in domestic markets and to importers. Large differences exist in functional characteristics amongst wheat that vary by protein level and class. The purpose of this paper is to analyze the demand for

William W. Wilson; Wesley W. Wilson; Bruce L. Dahl

2005-01-01

153

Registration of 'Bill Brown' Wheat  

Technology Transfer Automated Retrieval System (TEKTRAN)

‘Bill Brown’ (Reg. No. CV-133, PI 653260) hard red winter wheat (Triticum aestivum L.) was developed by the Colorado Agricultural Experiment Station and released in August 2007 through an exclusive marketing agreement with the Colorado Wheat Research Foundation. In addition to researchers at Colorad...

154

Wheat landraces: A mini review  

Technology Transfer Automated Retrieval System (TEKTRAN)

Farmers developed and utilized diverse wheat landraces to meet the complexity of a multitude of spatio-temporal, agro-ecological systems and to provide reliable sustenance and a sustainable food source to local communities. The genetic structure of wheat landraces is an evolutionary approach to surv...

155

Wheat-Legume Composite Flour Quality  

Microsoft Academic Search

Wheat-legume composite flours were produced by blending Canada Western Extra Strong (CWES) and Canada Western Red Spring (CWRS) wheat with varying amounts of three legume proteins. Legume protein addition produced breads with lower specific loaf volume, coarser crumb and firmer texture, and cooked white-salted noodles with greater compression stress and less cutting stress than the wheat controls. The CWES wheat

Dora Fenn; Odean M. Lukow; Gavin Humphreys; Paul G. Fields; Joyce I. Boye

2010-01-01

156

Hard Spring Wheat Technical Committee 2006 Crop  

Technology Transfer Automated Retrieval System (TEKTRAN)

Breeders’ experimental lines of wheat are evaluated for overall quality before being released for commercial production. The Hard Spring Wheat Technical Committee provides milling and baking quality data on breeders’ experimental lines of wheat that are annually submitted to the Wheat Quality Counc...

157

BREEDING WHEAT FOR RESISTANCE TO INSECTS  

Technology Transfer Automated Retrieval System (TEKTRAN)

Host-plant resistance plays an important role in the management of the insect pests of wheat (Triticum sp.). Five pests, Hessian fly (Mayetiola destructor), Russian wheat aphid (Diuraphis noxia), wheat midge (Sitodiplosis mosellana), greenbug (Schizaphis graminum) and the wheat stem sawfly (Cephus s...

158

On the Progenitors of Collapsars  

NASA Astrophysics Data System (ADS)

We investigate possible progenitor stars of Type I collapsars that are assumed to be responsible for the long class of GRBs. Our basic assumption is that in close binary systems a bare massive helium core is formed. This may occur either: (1) by losing the envelope by Roche-Lobe overflow to the companion, or (2) by a merger. For the first case, we will assume 10% of Keplerian rotation of the helium core, as predicted by simulations of rotating massive single stars. In the second case, even faster rotation may occur and we adopt 30%. We then follow the evolution of these cores, initially 15 solar masses of 10% solar metal content, from onset of central helium burning until onset of core collapse. In order to obtain the angular momentum distribution in the pre-collapsed stellar models we investigate different physical models for angular momentum transport and compare the results with what would be required to from a centrifugally supported disk around a central compact object. We also study angular momentum reduction by mass loss. We find that, if only rotationally induced instabilities (Heger et al. 2000) are considered, or magnetic fields (Spruit 2001) and no mass loss, sufficient angular momentum may remain in the core to power a collapsar. However, when this description of magnetic torques is combined with mass loss, the resulting angular momentum is too low. Magnetic field torques as described by Spruit & Phinney (1998) result in too low spin rates in any case studied. This work has been supported by the NSF (AST-9731569) and the DOE (B347885).

Woosley, S. E.; Heger, A.

2001-05-01

159

STELLAR BINARY COMPANIONS TO SUPERNOVA PROGENITORS  

SciTech Connect

For typical models of binary statistics, 50%-80% of core-collapse supernova (ccSN) progenitors are members of a stellar binary at the time of the explosion. Independent of any consequences of mass transfer, this has observational consequences that can be used to study the binary properties of massive stars. In particular, the secondary companion to the progenitor of a Type Ib/c SN is frequently (approx50%) the more optically luminous star since the high effective temperatures of the stripped progenitors make it relatively easy for a lower luminosity, cooler secondary to emit more optical light. Secondaries to the lower mass progenitors of Type II SN will frequently produce excess blue emission relative to the spectral energy distribution of the red primary. Available data constrain the models weakly. Any detected secondaries also provide an independent lower bound on the progenitor mass and, for historical SN, show that it was not a Type Ia event. Bright ccSN secondaries have an unambiguous, post-explosion observational signature-strong, blueshifted, relatively broad absorption lines created by the developing SN remnant (SNR). These can be used to locate historical SN with bright secondaries, confirm that a source is a secondary, and, potentially, measure abundances of ccSN ejecta. Luminous, hot secondaries will re-ionize the SNR on timescales of 100-1000 yr that are faster than re-ionization by the reverse shock, creating peculiar H II regions due to the high metallicity and velocities of the ejecta.

Kochanek, Christopher S. [Department of Astronomy, Ohio State University, 140 West 18th Avenue, Columbus, OH 43210 (United States)

2009-12-20

160

Progenitors of Core-Collapse Supernovae  

NASA Astrophysics Data System (ADS)

Knowledge of the progenitors of core-collapse supernovae is a fundamental component in understanding the explosions. The recent progress in finding such stars is reviewed. The minimum initial mass that can produce a supernova (SN) has converged to 8 ± 1 M from direct detections of red supergiant progenitors of II-P SNe and the most massive white dwarf progenitors, although this value is model dependent. It appears that most type Ibc SNe arise from moderate mass interacting binaries. The highly energetic, broad-lined Ic SNe are likely produced by massive, Wolf-Rayet progenitors. There is some evidence to suggest that the majority of massive stars above 20 M may collapse quietly to black holes and that the explosions remain undetected. The recent discovery of a class of ultrabright type II SNe and the direct detection of some progenitor stars bearing luminous blue variable characteristics suggest some very massive stars do produce highly energetic explosions. The physical mechanism is under debate, and these SNe pose a challenge to stellar evolutionary theory.

Smartt, Stephen J.

2009-09-01

161

Syntenic Relationships between the U and M Genomes of Aegilops, Wheat and the Model Species Brachypodium and Rice as Revealed by COS Markers.  

PubMed

Diploid Aegilops umbellulata and Ae. comosa and their natural allotetraploid hybrids Ae. biuncialis and Ae. geniculata are important wild gene sources for wheat. With the aim of assisting in alien gene transfer, this study provides gene-based conserved orthologous set (COS) markers for the U and M genome chromosomes. Out of the 140 markers tested on a series of wheat-Aegilops chromosome introgression lines and flow-sorted subgenomic chromosome fractions, 100 were assigned to Aegilops chromosomes and six and seven duplications were identified in the U and M genomes, respectively. The marker-specific EST sequences were BLAST-ed to Brachypodium and rice genomic sequences to investigate macrosyntenic relationships between the U and M genomes of Aegilops, wheat and the model species. Five syntenic regions of Brachypodium identified genome rearrangements differentiating the U genome from the M genome and from the D genome of wheat. All of them seem to have evolved at the diploid level and to have been modified differentially in the polyploid species Ae. biuncialis and Ae. geniculata. A certain level of wheat-Aegilops homology was detected for group 1, 2, 3 and 5 chromosomes, while a clearly rearranged structure was showed for the group 4, 6 and 7 Aegilops chromosomes relative to wheat. The conserved orthologous set markers assigned to Aegilops chromosomes promise to accelerate gene introgression by facilitating the identification of alien chromatin. The syntenic relationships between the Aegilops species, wheat and model species will facilitate the targeted development of new markers specific for U and M genomic regions and will contribute to the understanding of molecular processes related to allopolyploidization. PMID:23940651

Molnár, István; Simková, Hana; Leverington-Waite, Michelle; Goram, Richard; Cseh, András; Vrána, Jan; Farkas, András; Doležel, Jaroslav; Molnár-Láng, Márta; Griffiths, Simon

2013-08-05

162

Complementation of sugary-1 Phenotype in Rice Endosperm with the Wheat Isoamylase1 Gene Supports a Direct Role for Isoamylase1 in Amylopectin Biosynthesis  

PubMed Central

To examine the role of isoamylase1 (ISA1) in amylopectin biosynthesis in plants, a genomic DNA fragment from Aegilops tauschii was introduced into the ISA1-deficient rice (Oryza sativa) sugary-1 mutant line EM914, in which endosperm starch is completely replaced by phytoglycogen. A. tauschii is the D genome donor of wheat (Triticum aestivum), and the introduced fragment effectively included the gene for ISA1 for wheat (TaISA1) that was encoded on the D genome. In TaISA1-expressing rice endosperm, phytoglycogen synthesis was substantially replaced by starch synthesis, leaving only residual levels of phytoglycogen. The levels of residual phytoglycogen present were inversely proportional to the expression level of the TaISA1 protein, although the level of pullulanase that had been reduced in EM914 was restored to the same level as that in the wild type. Small but significant differences were found in the amylopectin chain-length distribution, gelatinization temperatures, and A-type x-ray diffraction patterns of the starches from lines expressing TaISA1 when compared with wild-type rice starch, although in the first two parameters, the effect was proportional to the expression level of TaISA. The impact of expression levels of ISA1 on starch structure and properties provides support for the view that ISA1 is directly involved in the synthesis of amylopectin.

Kubo, Akiko; Rahman, Sadequr; Utsumi, Yoshinori; Li, Zhongyi; Mukai, Yasuhiko; Yamamoto, Maki; Ugaki, Masashi; Harada, Kyuya; Satoh, Hikaru; Konik-Rose, Christine; Morell, Matthew; Nakamura, Yasunori

2005-01-01

163

Circulating and tissue resident endothelial progenitor cells.  

PubMed

Progenitor cells for the endothelial lineage have been widely investigated for more than a decade, but continue to be controversial since no unique identifying marker has yet been identified. This review will begin with a discussion of the basic tenets originally proposed for proof that a cell displays properties of an endothelial progenitor cell. We then provide an overview of the methods for putative endothelial progenitor cell derivation, expansion, and enumeration. This discussion includes consideration of cells that are present in the circulation as well as cells resident in the vascular endothelial intima. Finally, we provide some suggested changes in nomenclature that would greatly clarify and demystify the cellular elements involved in vascular repair. J. Cell. Physiol. 229: 10-16, 2014. © 2013 Wiley Periodicals, Inc. PMID:23794280

Basile, David P; Yoder, Mervin C

2014-01-01

164

THE AGES OF TYPE Ia SUPERNOVA PROGENITORS  

SciTech Connect

Using light curves and host galaxy spectra of 101 Type Ia supernovae (SNe Ia) with redshift z {approx}< 0.3 from the Sloan Digital Sky Survey Supernova Survey (SDSS-SN), we derive the SN Ia rate as a function of progenitor age (the delay time distribution, DTD). We use the VESPA stellar population synthesis algorithm to analyze the SDSS spectra of all galaxies in the field searched by SDSS-SN, giving us a reference sample of 77,000 galaxies for our SN Ia hosts. Our method does not assume any a priori shape for the DTD and is therefore minimally parametric. We present the DTD in physical units for high-stretch (luminous, slow declining) and low-stretch (subluminous, fast declining) supernovae in three progenitor age bins. We find strong evidence of two progenitor channels: one that produces high-stretch SNe Ia {approx}<400 Myr after the birth of the progenitor system, and one that produces low-stretch SNe Ia with a delay {approx}>2.4 Gyr. We find that each channel contributes roughly half of the Type Ia rate in our reference sample. We also construct the average spectra of high-stretch and low-stretch SN Ia host galaxies, and find that the difference of these spectra looks like a main-sequence B star with nebular emission lines indicative of star formation. This supports our finding that there are two populations of SNe Ia, and indicates that the progenitors of high-stretch supernovae are at the least associated with very recent star formation in the last few tens of Myr. Our results provide valuable constraints for models of Type Ia progenitors and may help improve the calibration of SNe Ia as standard candles.

Brandt, Timothy D.; Aubourg, Eric; Strauss, Michael A. [Department of Astrophysical Sciences, Peyton Hall, Princeton University, Princeton, NJ 08544 (United States); Tojeiro, Rita [Institute of Cosmology and Gravitation, University of Portsmouth, Dennis Sciama Building, Burnaby Road, Portsmouth, PO1 3FX (United Kingdom); Heavens, Alan [SUPA, Institute for Astronomy, University of Edinburgh, Royal Observatory, Blackford Hill, Edinburgh EH9-3HJ (United Kingdom); Jimenez, Raul [ICREA and Institute for Sciences of the Cosmos (ICCUB), University of Barcelona, Barcelona 08028 (Spain)

2010-09-15

165

Magnetized massive stars as magnetar progenitors  

NASA Astrophysics Data System (ADS)

The origin of ultra-intense magnetic fields on magnetars is a mystery in modern astrophysics. We model the core collapse dynamics of massive progenitor stars with high surface magnetic fields in the theoretical framework of a self-similar general polytropic magnetofluid under self-gravity with a quasi-spherical symmetry. With the specification of physical parameters such as mass density, temperature, magnetic field and wind mass-loss rate on the progenitor stellar surface and the consideration of a rebound shock breaking through the stellar interior and envelope, we find a remnant compact object (i.e. neutron star) left behind at the centre with a radius of ~106 cm and a mass range of ~1-3Msolar. Moreover, we find that surface magnetic fields of such a type of compact objects can be ~1014-1015 G, consistent with those inferred for magnetars which include soft gamma-ray repeaters and anomalous X-ray pulsars. The magnetic field enhancement factor critically depends on the self-similar scaling index n, which also determines the initial density distribution of the massive progenitor. We propose magnetized massive stars as magnetar progenitors based on the magnetohydrodynamic evolution of the gravitational core collapse and rebound shock. Our physical mechanism, which does not necessarily require ad hoc dynamo amplification within a fast spinning neutron star, favours the `fossil-field' scenario of forming magnetars from the strongly magnetized core collapse inside massive progenitor stars. The resulting magnetic field strength on the surface of the remnant proto-neutron star is proportional to the surface magnetic field strength of the progenitor and to the neutron star mass itself, while it anti-correlates with the progenitor stellar mass. With a range of surface magnetic field strengths over massive progenitor stars, our scenario allows a continuum of magnetic field strengths from pulsars to magnetars. The intense Lorentz force inside a magnetar may break the crust of a neutron star into pieces to various extents. Coupled with the magnetar spin, the magnetospheric configuration of a magnetar is most likely variable in the presence of exposed convection, differential rotation, equatorial bulge, bursts of interior magnetic flux ropes as well as rearrangement of broken pieces of the crust. Sporadic and violent releases of accumulated magnetic energies and a broken crust are the underlying causes for various observed high-energy activities of magnetars.

Hu, Ren-Yu; Lou, Yu-Qing

2009-06-01

166

Individual Retinal Progenitor Cells Display Extensive Heterogeneity of Gene Expression  

Microsoft Academic Search

The development of complex tissues requires that mitotic progenitor cells integrate information from the environment. The highly varied outcomes of such integration processes undoubtedly depend at least in part upon variations among the gene expression programs of individual progenitor cells. To date, there has not been a comprehensive examination of these differences among progenitor cells of a particular tissue. Here,

Jeffrey M. Trimarchi; Michael B. Stadler; Constance L. Cepko; Patrick Callaerts

2008-01-01

167

Single Degenerate Progenitors of Type Ia Supernovae  

NASA Astrophysics Data System (ADS)

There is a general agreement that Type Ia supernovae correspond to the thermonuclear runaway of a white dwarf (WD) in a compact binary. The details of these progenitor systems are still unclear. Using the population synthesis code SeBa and several assumption for the WD retention efficiency, we estimate the delay times and supernova rates for the single degenerate scenario.

Bours, Madelon; Toonen, Silvia; Nelemans, Gijs

2013-01-01

168

The progenitors of subluminous type Ia supernovae  

SciTech Connect

We find that spectroscopically peculiar subluminous SNe Ia come from an old population. Of the thirteen subluminous SNe Ia known, nine are found in E/S0 galaxies, and the remainder are found in early-type spirals. The probability that this is a chance occurrence is only 0.1%. The finding that subluminous SNe Ia are associated with an older stellar population indicates that for a sufficiently large lookback time (already accessible in current high redshift searches) they will not be found. Due to a scarcity in old populations, hydrogen and helium main sequence stars and He red giant stars that undergo Roche lobe overflow are unlikely to be the progenitors of subluminous SNe Ia. Earlier findings that overluminous SNe Ia (DELTA m{sub 15} (B) < 0.94) come from a young progenitor population are confirmed. The fact that subluminous SNe Ia and overluminous SNe Ia come from different progenitor populations and also have different properties is a prediction of the CO white dwarf merger progenitor scenario.

Howell, D. Andrew

2001-02-01

169

Search for Progenitors of SN Ia  

Microsoft Academic Search

While supernovae of Type Ia (SNe Ia) play a prominent role in many astrophysical environments and their use as cosmological tools is being pushed to redshift 1 and beyond, the nature of their progenitors remains substantially unknown. This represents a major limitation both for understanding the astrophysical phenomena in which SNe Ia are involved, and for their use as cosmological

Ralf Napiwotzki

2001-01-01

170

Circulating Endothelial Progenitor Cells in Cerebrovascular Disease  

Microsoft Academic Search

Stroke is associated with high disability and mortality burdens worldwide, but there are few ef- fective and widely available therapies. There is therefore a need to develop treatments that pro- mote the repair and regeneration of ischemic brain tissue. In this regard, a population of adult stem cells-called endothelial progenitor cells (EPCs)-has been identified in peripheral blood that could provide

Keun-Hwa Jung; Jae-Kyu Roh

2008-01-01

171

Real Time Imaging of Human Progenitor Neurogenesis  

Microsoft Academic Search

Human neural progenitors are increasingly being employed in drug screens and emerging cell therapies targeted towards neurological disorders where neurogenesis is thought to play a key role including developmental disorders, Alzheimer’s disease, and depression. Key to the success of these applications is understanding the mechanisms by which neurons arise. Our understanding of development can provide some guidance but since little

Thomas M. Keenan; Aaron D. Nelson; Jeffrey R. Grinager; Jarett C. Thelen; Clive N. Svendsen

2010-01-01

172

In vivo identification of periodontal progenitor cells.  

PubMed

The periodontal ligament contains progenitor cells; however, their identity and differentiation potential in vivo remain poorly characterized. Previous results have suggested that periodontal tissue progenitors reside in perivascular areas. Therefore, we utilized a lineage-tracing approach to identify and track periodontal progenitor cells from the perivascular region in vivo. We used an alpha-smooth muscle actin (?SMA) promoter-driven and tamoxifen-inducible Cre system (?SMACreERT2) that, in combination with a reporter mouse line (Ai9), permanently labels a cell population, termed 'SMA9'. To trace the differentiation of SMA9-labeled cells into osteoblasts/cementoblasts, we utilized a Col2.3GFP transgene, while expression of Scleraxis-GFP was used to follow differentiation into periodontal ligament fibroblasts during normal tissue formation and remodeling following injury. In uninjured three-week-old SMA9 mice, tamoxifen labeled a small population of cells in the periodontal ligament that expanded over time, particularly in the apical region of the root. By 17 days and 7 weeks after labeling, some SMA9-labeled cells expressed markers indicating differentiation into mature lineages, including cementocytes. Following injury, SMA9 cells expanded, and differentiated into cementoblasts, osteoblasts, and periodontal ligament fibroblasts. SMA9-labeled cells represent a source of progenitors that can give rise to mature osteoblasts, cementoblasts, and fibroblasts within the periodontium. PMID:23735585

Roguljic, H; Matthews, B G; Yang, W; Cvija, H; Mina, M; Kalajzic, I

2013-06-04

173

Proteoglycan synthesis by hematopoietic progenitor cells  

SciTech Connect

The synthesis of proteoglycans (PG) by hematopoietic stromal cells has been reported. But PG synthesis by hematopoietic progenitor cells has not been explored. We have studied synthesis, cellular distribution, and molecular characteristics of PG by a cloned interleukin-3 (IL-3)-dependent hematopoietic progenitor cell line, FDCP-1, which is cloned from murine long-term marrow cultures. Under appropriate conditions the cell can differentiate into granulocytes and macrophages, and therefore, can be considered CFU-GM equivalent. The pattern of PG synthesis was studied by 35SO4 labeling. FDCP-1 cells actively synthesize PG, which are distributed in the intracellular, membrane-associated (MP), and extracellular pools. After purification of the 35S-labeled material by ion-exchange and gel filtration techniques, a single chondroitin sulfate-PG (CIS-PG) was observed to be present in the three studied pools. By Sepharose CL-4B chromatography, this PG has a Kav of 0.47, which after alkaline treatment is shifted to a Kav of 0.67. This indicates the proteoglycan nature of the 35SO4-labeled material. The MP CIS-PG is not stable. It is released to the culture medium where it is subsequently processed. However, in the presence of hematopoietic stromal cells D2X, the stability of MP proteoglycan of FDCP-1 cells is enhanced, suggesting that the synthesis of PG by progenitor cells and its accumulation in the membrane may have a role in the interaction between progenitor and stromal cells.

Minguell, J.J.; Tavassoli, M. (Veterans Administration Medical Center, Jackson, MS (USA))

1989-05-15

174

Gamma-Ray Burst Environments and Progenitors  

Microsoft Academic Search

Likely progenitors for gamma-ray bursts (GRBs) are the mergers of compact objects or the explosions of massive stars. These two cases have distinctive environments for the GRB afterglow: the compact object explosions occur in the interstellar medium (ISM) and those of massive stars occur in the preburst stellar wind. We calculate the expected afterglow for a burst in a Wolf-Rayet

Roger A. Chevalier; Zhi-Yun Li

1999-01-01

175

Stem cells, progenitors and myelin repair  

Microsoft Academic Search

Remyelination, the process by which new myelin sheaths are restored to demyelinated axons, represents one of the most compelling examples of adult multipotent progenitor cells contributing to regeneration of the injured central nervous system (CNS). This process can occur with remarkable efficiency in both clinical disease, such as mul- tiple sclerosis, and in experimental models, revealing an impressive ability of

Chao Zhao; Stephen P. J. Fancy; Laurent Magy; Joanna E. Urwin; Robin J. M. Franklin

2005-01-01

176

Spring Wheat in North Kazakhstan.  

National Technical Information Service (NTIS)

This book highlights problems in the biology of spring (soft) and durum (hard) wheat, its place in crop rotation schedules, basic and presowing land preparation, weed control, and varietal trials. It describes various agronomical measures to increase the ...

A. I. Baraev

1983-01-01

177

SUPERNOVA REMNANT PROGENITOR MASSES IN M31  

SciTech Connect

Using Hubble Space Telescope photometry, we age-date 59 supernova remnants (SNRs) in the spiral galaxy M31 and use these ages to estimate zero-age main-sequence masses (M{sub ZAMS}) for their progenitors. To accomplish this, we create color-magnitude diagrams (CMDs) and employ CMD fitting to measure the recent star formation history of the regions surrounding cataloged SNR sites. We identify any young coeval population that likely produced the progenitor star, then assign an age and uncertainty to that population. Application of stellar evolution models allows us to infer the M{sub ZAMS} from this age. Because our technique is not contingent on identification or precise location of the progenitor star, it can be applied to the location of any known SNRs. We identify significant young star formation around 53 of the 59 SNRs and assign progenitor masses to these, representing a factor of {approx}2 increase over currently measured progenitor masses. We consider the remaining six SNRs as either probable Type Ia candidates or the result of core-collapse progenitors that have escaped their birth sites. In general, the distribution of recovered progenitor masses is bottom-heavy, showing a paucity of the most massive stars. If we assume a single power-law distribution, dN/dM{proportional_to}M{sup {alpha}}, then we find a distribution that is steeper than a Salpeter initial mass function (IMF) ({alpha} = -2.35). In particular, we find values of {alpha} outside the range -2.7 {>=} {alpha} {>=} -4.4 to be inconsistent with our measured distribution at 95% confidence. If instead we assume a distribution that follows a Salpeter IMF up to some maximum mass, then we find that values of M{sub Max} > 26 are inconsistent with the measured distribution at 95% confidence. In either scenario, the data suggest that some fraction of massive stars may not explode. The result is preliminary and requires more SNRs and further analysis. In addition, we use our distribution to estimate a minimum mass for core collapse between 7.0 and 7.8 M{sub Sun }.

Jennings, Zachary G.; Williams, Benjamin F.; Dalcanton, Julianne J.; Gilbert, Karoline M.; Fouesneau, Morgan; Weisz, Daniel R. [Department of Astronomy, University of Washington Seattle, Box 351580, WA 98195 (United States); Murphy, Jeremiah W. [Department of Astrophysical Sciences, Princeton University, Princeton, NJ 08544 (United States); Dolphin, Andrew E., E-mail: zachjenn@uw.edu, E-mail: adolphin@raytheon.com [Raytheon, 1151 East Hermans Road, Tucson, AZ 85706 (United States)

2012-12-10

178

Dough Rheology and Wet Milling of Hard Waxy Wheat Flours  

Technology Transfer Automated Retrieval System (TEKTRAN)

To realize the full potential of waxy wheat (Triticum aestivum L.), wet milling of waxy wheat flour to produce gluten and waxy wheat starch was investigated. Flours of six advanced lines of waxy hard wheats, one normal hard wheat (‘Karl 92’), and one partial waxy wheat (‘Trego’) were fractionated by...

179

Progenitors of type Ia supernovae and their surviving companion stars  

NASA Astrophysics Data System (ADS)

Type Ia supernovae (SNe Ia) are the best cosmological distance indicator, however, there is still no agreement on the nature of their progenitors. There are mainly two progenitor scenarios, i.e., the single degenerate (SD) and double degenerate (DD) scenarios. In this article, we introduced our binary evolution models of various progenitor scenarios. We also obtained many properties of the surviving companions from various SD systems, which may be helpful for identifying SN Ia progenitor model. At present, it seems likely that more than one progenitor model may be required to explain the observed diversity of SNe Ia.

Wang, B.; Liu, Z.; Chen, H.; Jia, S.; Han, Z.

2013-02-01

180

WheatBlog .05b  

NSDL National Science Digital Library

Given the increasing interest in developing personal weblogs and online journals, many users may find the WheatBlog device quite enticing. The application is designed to maintain any number of blog and news pages on personal sites, and will certainly assist users in keeping track of various developments on any variety of such related endeavors. WheatBlog .05b is compatible with all operating systems.

181

A high-throughput method for the detection of homoeologous gene deletions in hexaploid wheat  

PubMed Central

Background Mutational inactivation of plant genes is an essential tool in gene function studies. Plants with inactivated or deleted genes may also be exploited for crop improvement if such mutations/deletions produce a desirable agronomical and/or quality phenotype. However, the use of mutational gene inactivation/deletion has been impeded in polyploid plant species by genetic redundancy, as polyploids contain multiple copies of the same genes (homoeologous genes) encoded by each of the ancestral genomes. Similar to many other crop plants, bread wheat (Triticum aestivum L.) is polyploid; specifically allohexaploid possessing three progenitor genomes designated as 'A', 'B', and 'D'. Recently modified TILLING protocols have been developed specifically for mutation detection in wheat. Whilst extremely powerful in detecting single nucleotide changes and small deletions, these methods are not suitable for detecting whole gene deletions. Therefore, high-throughput methods for screening of candidate homoeologous gene deletions are needed for application to wheat populations generated by the use of certain mutagenic agents (e.g. heavy ion irradiation) that frequently generate whole-gene deletions. Results To facilitate the screening for specific homoeologous gene deletions in hexaploid wheat, we have developed a TaqMan qPCR-based method that allows high-throughput detection of deletions in homoeologous copies of any gene of interest, provided that sufficient polymorphism (as little as a single nucleotide difference) amongst homoeologues exists for specific probe design. We used this method to identify deletions of individual TaPFT1 homoeologues, a wheat orthologue of the disease susceptibility and flowering regulatory gene PFT1 in Arabidopsis. This method was applied to wheat nullisomic-tetrasomic lines as well as other chromosomal deletion lines to locate the TaPFT1 gene to the long arm of chromosome 5. By screening of individual DNA samples from 4500 M2 mutant wheat lines generated by heavy ion irradiation, we detected multiple mutants with deletions of each TaPFT1 homoeologue, and confirmed these deletions using a CAPS method. We have subsequently designed, optimized, and applied this method for the screening of homoeologous deletions of three additional wheat genes putatively involved in plant disease resistance. Conclusions We have developed a method for automated, high-throughput screening to identify deletions of individual homoeologues of a wheat gene. This method is also potentially applicable to other polyploidy plants.

2010-01-01

182

Human trophoblast progenitors: where do they reside?  

PubMed

In humans, very little is known about the factors that regulate trophoblast (TB) specification, expansion of the initial TB population, and formation of the cytotrophoblast (CTB) populations that populate the chorionic villi. The absence of human trophoblast progenitor cell (hTPC) lines that can be propagated in vitro has been a limiting factor. Because attempts to derive TB stem cells from the trophectoderm of the human blastocyst have so far failed, investigators use alternative systems as cell culture models including TBs derived from human embryonic stem cells (hESCs), immortalized CTBs, and cell lines established from TB tumors. Additionally, the characteristics of mature TBs have been extensively studied using primary cultures of CTBs and explants of placental chorionic villi. However, none of these models can be used to study TB progenitor self-renewal and differentiation. Furthermore, the propagation of human TB progenitors from villous CTBs (vCTBs) has not been achieved. The downregulation of key markers of cell cycle progression in vCTBs by the end of the first trimester of pregnancy may indicate that these cells are not a source of human TB progenitors later in pregnancy. In contrast, mesenchymal cells of the villi and chorion continue to proliferate until the end of pregnancy. We recently reported isolation of continuously self-renewing hTPCs from chorionic mesenchyme and showed that they differentiated into the mature TB cell types of the villi, evidence that they can function as TB progenitors. This new cell culture model enables a molecular analysis of the seminal steps in human TB differentiation that have yet to be studied in humans. In turn, this information can be used to trace the origins of pregnancy complications that are associated with faulty TB growth and differentiation. PMID:23329637

Genbacev, Olga; Lamb, Julie D; Prakobphol, Akraporn; Donne, Matt; McMaster, Michael T; Fisher, Susan J

2013-01-17

183

Origin of hemopoietic stromal progenitor cells in chimeras  

SciTech Connect

Intravenously injected bone marrow cells do not participate in the regeneration of hemopoietic stromal progenitors in irradiated mice, nor in the curetted parts of the recipient's marrow. The hemopoietic stromal progenitors in allogeneic chimeras are of recipient origin. The adherent cell layer (ACL) of long-term cultures of allogeneic chimera bone marrow contains only recipient hemopoietic stromal progenitors. However, in ectopic hemopoietic foci produced by marrow implantation under the renal capsule and repopulated by the recipient hemopoietic cells after irradiation and reconstitution by syngeneic hemopoietic cells, the stromal progenitors were of implant donor origin, as were stromal progenitors of the ACL in long-term cultures of hemopoietic cells from ectopic foci. Our results confirm that the stromal and hemopoietic progenitors differ in origin and that hemopoietic stromal progenitors are not transplantable by the intravenous route in mice.

Chertkov, J.L.; Drize, N.J.; Gurevitch, O.A.; Samoylova, R.S.

1985-12-01

184

The Changing Landscape of Type Ia Supernova Progenitors  

NASA Astrophysics Data System (ADS)

In the past, scientists studying progenitors of Type Ia supernova progenitors were faced with a problem getting agreement between the progenitors that population synthesis studies could get in large enough numbers to explain the SNIa population and the progenitors that engine theorists felt worked. This landscape has rapidly changed in the past few years with the dramatic change in our understanding of thermonuclear explosions. I will review the current situation of these engines in the context of supernova progenitors. These new results are prompting new population synthesis studies and I will review some of the recent results in this field. We may be able to distinguish these progenitors based on detailed spectra. I will conclude with a discussion of the current work on SNIa light-curve and spectra calculations and their relevance to SNIa progenitors.

Fryer, Chris

2012-03-01

185

Physical mapping of a large plant genome using global high-information-content-fingerprinting: the distal region of the wheat ancestor Aegilops tauschii chromosome 3DS  

PubMed Central

Background Physical maps employing libraries of bacterial artificial chromosome (BAC) clones are essential for comparative genomics and sequencing of large and repetitive genomes such as those of the hexaploid bread wheat. The diploid ancestor of the D-genome of hexaploid wheat (Triticum aestivum), Aegilops tauschii, is used as a resource for wheat genomics. The barley diploid genome also provides a good model for the Triticeae and T. aestivum since it is only slightly larger than the ancestor wheat D genome. Gene co-linearity between the grasses can be exploited by extrapolating from rice and Brachypodium distachyon to Ae. tauschii or barley, and then to wheat. Results We report the use of Ae. tauschii for the construction of the physical map of a large distal region of chromosome arm 3DS. A physical map of 25.4 Mb was constructed by anchoring BAC clones of Ae. tauschii with 85 EST on the Ae. tauschii and barley genetic maps. The 24 contigs were aligned to the rice and B. distachyon genomic sequences and a high density SNP genetic map of barley. As expected, the mapped region is highly collinear to the orthologous chromosome 1 in rice, chromosome 2 in B. distachyon and chromosome 3H in barley. However, the chromosome scale of the comparative maps presented provides new insights into grass genome organization. The disruptions of the Ae. tauschii-rice and Ae. tauschii-Brachypodium syntenies were identical. We observed chromosomal rearrangements between Ae. tauschii and barley. The comparison of Ae. tauschii physical and genetic maps showed that the recombination rate across the region dropped from 2.19 cM/Mb in the distal region to 0.09 cM/Mb in the proximal region. The size of the gaps between contigs was evaluated by comparing the recombination rate along the map with the local recombination rates calculated on single contigs. Conclusions The physical map reported here is the first physical map using fingerprinting of a complete Triticeae genome. This study demonstrates that global fingerprinting of the large plant genomes is a viable strategy for generating physical maps. Physical maps allow the description of the co-linearity between wheat and grass genomes and provide a powerful tool for positional cloning of new genes.

2010-01-01

186

Galactic constraints on supernova progenitor models  

NASA Astrophysics Data System (ADS)

Aims: To estimate the mean masses of oxygen and iron ejected per each type of supernovae (SNe) event from observations of the elemental abundance patterns in the Galactic disk and constrain the relevant SNe progenitor models. Methods: We undertake a statistical analysis of the radial abundance distributions in the Galactic disk within a theoretical framework for Galactic chemical evolution which incorporates the influence of spiral arms. This framework has been shown to recover the non-linear behaviour in radial gradients, the mean masses of oxygen and iron ejected during SNe explosions to be estimated, and constraints to be placed on SNe progenitor models. Results: (i) The mean mass of oxygen ejected per core-collapse SNe (CC SNe) event (which are concentrated within spiral arms) is ~0.27 M?; (ii) the mean mass of iron ejected by tardy Type Ia SNe (SNeIa, whose progenitors are older/longer-lived stars with ages ?100 Myr and up to several Gyr, which do not concentrate within spiral arms) is ~0.58 M?; (iii) the upper mass of iron ejected by prompt SNeIa (SNe whose progenitors are younger/shorter-lived stars with ages ?100 Myr, which are concentrated within spiral arms) is ?0.23 M? per event; (iv) the corresponding mean mass of iron produced by CC SNe is ?0.04 M? per event; (v) short-lived SNe (core-collapse or prompt SNeIa) supply ~85% of the Galactic disk's iron. Conclusions: The inferred low mean mass of oxygen ejected per CC SNe event implies a low upper mass limit for the corresponding progenitors of ~23 M?, otherwise the Galactic disk would be overabundant in oxygen. This inference is the consequence of the non-linear dependence between the upper limit of the progenitor initial mass and the mean mass of oxygen ejected per CC SNe explosion. The low mean mass of iron ejected by prompt SNeIa, relative to the mass produced by tardy SNeIa (~2.5 times lower), prejudices the idea that both sub-populations of SNeIa have the same physical nature. We suggest that, perhaps, prompt SNeIa are more akin to CC SNe, and discuss the implications of such a suggestion.

Acharova, I. A.; Gibson, B. K.; Mishurov, Yu. N.; Kovtyukh, V. V.

2013-09-01

187

21 CFR 137.190 - Cracked wheat.  

Code of Federal Regulations, 2013 CFR

...DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) FOOD FOR HUMAN CONSUMPTION CEREAL FLOURS AND RELATED PRODUCTS Requirements for Specific Standardized Cereal Flours and Related Products § 137.190 Cracked wheat. Cracked wheat...

2013-04-01

188

Human progenitor cells for bone engineering applications.  

PubMed

In this report, the authors review the human skeleton and the increasing burden of bone deficiencies, the limitations encountered with the current treatments and the opportunities provided by the emerging field of cell-based bone engineering. Special emphasis is placed on different sources of human progenitor cells, as well as their pros and cons in relation to their utilization for the large-scale construction of functional bone-engineered substitutes for clinical applications. It is concluded that, human pluripotent stem cells represent a valuable source for the derivation of progenitor cells, which combine the advantages of both embryonic and adult stem cells, and indeed display high potential for the construction of functional substitutes for bone replacement therapies. PMID:23642054

de Peppo, G M; Thomsen, P; Karlsson, C; Strehl, R; Lindahl, A; Hyllner, J

2013-06-01

189

Cardiac Progenitors and the Embryonic Cell Cycle  

PubMed Central

Despite the critical importance of proper cell cycle regulation in establishing the correct morphology of organs and tissues during development, relatively little is known about how cell proliferation is regulated in a tissue-specific manner. The control of cell proliferation within the developing heart is of considerable interest, given the high prevalence of congenital cardiac abnormalities among humans, and recent interest in the isolation of cardiac progenitor populations. We therefore review studies exploring the contribution of cell proliferation to overall cardiac morphology and the molecular mechanisms regulating this process. In addition, we also review recent studies that have identified progenitor cell populations within the adult myocardium, as well as those exploring the capability of differentiated myocardial cells to proliferate post-natally. Thus, the exploration of cardiomyoctye cell cycle regulation, both during development as well as in the adult heart, promises to yield many exciting and important discoveries over the coming years.

Goetz, Sarah C.; Conlon, Frank L.

2009-01-01

190

Progenitor cells for ocular surface regenerative therapy.  

PubMed

The integrity and normal function of the corneal epithelium are essential for maintaining the cornea's transparency and vision. The existence of a cell population with progenitor characteristics in the limbus maintains a dynamic of constant epithelial repair and renewal. Currently, cell-based therapies for bio-replacement, such as cultured limbal epithelial transplantation and cultured oral mucosal epithelial transplantation, present very encouraging clinical results for treating limbal stem cell deficiencies. Another emerging therapeutic strategy consists of obtaining and implementing human progenitor cells of different origins using tissue engineering methods. The development of cell-based therapies using stem cells, such as human adult mesenchymal stromal cells, represents a significant breakthrough in the treatment of certain eye diseases and also offers a more rational, less invasive and more physiological approach to ocular surface regeneration. PMID:23257987

Casaroli-Marano, Ricardo P; Nieto-Nicolau, Nuria; Martínez-Conesa, Eva M

2012-12-18

191

The endocannabinoid system drives neural progenitor proliferation.  

PubMed

The discovery of multipotent neural progenitor (NP) cells has provided strong support for the existence of neurogenesis in the adult brain. However, the signals controlling NP proliferation remain elusive. Endocannabinoids, the endogenous counterparts of marijuana-derived cannabinoids, act as neuromodulators via presynaptic CB1 receptors and also control neural cell death and survival. Here we show that progenitor cells express a functional endocannabinoid system that actively regulates cell proliferation both in vitro and in vivo. Specifically, NPs produce endocannabinoids and express the CB1 receptor and the endocannabinoid-inactivating enzyme fatty acid amide hydrolase (FAAH). CB1 receptor activation promotes cell proliferation and neurosphere generation, an action that is abrogated in CB1-deficient NPs. Accordingly, proliferation of hippocampal NPs is increased in FAAH-deficient mice. Our results demonstrate that endocannabinoids constitute a new group of signaling cues that regulate NP proliferation and thus open novel therapeutic avenues for manipulation of NP cell fate in the adult brain. PMID:16037095

Aguado, Tania; Monory, Krisztina; Palazuelos, Javier; Stella, Nephi; Cravatt, Benjamin; Lutz, Beat; Marsicano, Giovanni; Kokaia, Zaal; Guzmán, Manuel; Galve-Roperh, Ismael

2005-07-21

192

Noninvasive Imaging of Administered Progenitor Cells  

SciTech Connect

The objective of this research grant was to develop an approach for labeling progenitor cells, specifically those that we had identified as being able to replace ischemic heart cells, so that the distribution could be followed non-invasively. In addition, the research was aimed at determining whether administration of progenitor cells resulted in improved myocardial perfusion and function. The efficiency and toxicity of radiolabeling of progenitor cells was to be evaluated. For the proposed clinical protocol, subjects with end-stage ischemic coronary artery disease were to undergo a screening cardiac positron emission tomography (PET) scan using N-13 ammonia to delineate myocardial perfusion and function. If they qualified based on their PET scan, they would undergo an in-hospital protocol whereby CD34+ cells were stimulated by the administration of granulocytes-colony stimulating factor (G-CSF). CD34+ cells would then be isolated by apharesis, and labeled with indium-111 oxine. Cells were to be re-infused and subjects were to undergo single photon emission computed tomography (SPECT) scanning to evaluate uptake and distribution of labeled progenitor cells. Three months after administration of progenitor cells, a cardiac PET scan was to be repeated to evaluate changes in myocardial perfusion and/or function. Indium oxine is a radiopharmaceutical for labeling of autologous lymphocytes. Indium-111 (In-111) decays by electron capture with a t{sub ˝} of 67.2 hours (2.8 days). Indium forms a saturated complex that is neutral, lipid soluble, and permeates the cell membrane. Within the cell, the indium-oxyquinolone complex labels via indium intracellular chelation. Following leukocyte labeling, ~77% of the In-111 is incorporated in the cell pellet. The presence of red cells and /or plasma reduces the labeling efficacy. Therefore, the product needed to be washed to eliminate plasma proteins. This repeated washing can damage cells. The CD34 selected product was a 90-99% pure population of leukocytes. Viability was assessed using Trypan blue histological analysis. We successfully isolated and labeled ~25-30 x 10{sup 7} CD34+ lymphocytes in cytokine mobilized progenitor cell apharesis harvests. Cells were also subjected to a stat gram stain to look for bacterial contamination, stat endotoxin LAL to look for endotoxin contamination, flow cytometry for evaluation of the purity of the cells and 14-day sterility culture. Colony forming assays confirm the capacity of these cells to proliferate and function ex-vivo with CFU-GM values of 26 colonies/ 1 x 10{sup 4} cells plated and 97% viability in cytokine augmented methylcellulose at 10-14 days in CO{sub 2} incubation. We developed a closed-processing system for the product labeling prior to infusion to maintain autologous cell integrity and sterility. Release criteria for the labeled product were documented for viability, cell count and differential, and measured radiolabel. We were successful in labeling the cells with up to 500 uCi/10{sup 8} cells, with viability of >98%. However, due to delays in getting the protocol approved by the FDA, the cells were not infused in humans in this location (although we did successfully use CD34+ cells in humans in a study in Australia). The approach developed should permit labeling of progenitor cells that can be administered to human subjects for tracking. The labeling approach should be useful for all progenitor cell types, although this would need to be verified since different cell lines may have differential radiosensitivity.

Steven R Bergmann, M.D., Ph.D.

2012-12-03

193

Growing Wheat. People on the Farm.  

ERIC Educational Resources Information Center

This booklet, one in a series about life on modern farms, describes the daily life of the Don Riffel family, wheat farmers in Kansas. Beginning with early morning, the booklet traces the family's activities through a typical harvesting day in July, while explaining how a wheat farm is run. The booklet also briefly describes the wheat growing…

Department of Agriculture, Washington, DC. Office of Governmental and Public Affairs.

194

HARD SPRING WHEAT TECHNICAL COMMITTEE 2007 CROP  

Technology Transfer Automated Retrieval System (TEKTRAN)

Twelve experimental lines of hard spring wheat were grown at up to five locations in 2007 and evaluated for kernel, milling, and bread baking quality against the check variety Glenn. Samples of wheat were submitted through the Wheat Quality Council and processed and milled at the USDA Hard Red Spri...

195

Supplementation of Wheat Gluten Protein1  

Microsoft Academic Search

Male weanling Wistar rats were fed diets containing wheat gluten (group 1), wheat gluten supplemented with lysine monohydrochloride (group 2), wheat gluten plus casein (group 3), casein (group 4), and egg albumin (group 5) as the dietary protein sources, as well as a diet free of protein (group 6). The nitrogen growth index of 8.6 for the group 1 animals

W. L. BANKS; J. B. ALLISON; R. W. WANNEMACHER

2010-01-01

196

Nestin Protein Is Phosphorylated in Adult Neural Stem/Progenitor Cells and Not Endothelial Progenitor Cells  

PubMed Central

An intermediate filament protein, Nestin, is known as a neural stem/progenitor cell marker. It was shown to be required for the survival and self-renewal of neural stem cells according to the phenotypes of Nestin knockout mice. Nestin expression has also been reported in vascular endothelial cells, and we recently reported Nestin expression in proliferating endothelial progenitor cells, but not in mature endothelial cells. Using quantitative phosphoproteome analysis, we studied differences in phosphorylation levels between CNS Nestin in adult neural stem cells and vascular Nestin in adult bone-marrow-derived endothelial progenitor cells. We detected 495 phosphopeptides in the cell lysates of adult CNS stem/progenitor cells and identified 11 significant phosphorylated amino acid residues in the Nestin protein. In contrast, endothelial progenitor cells showed no significant phosphorylation of Nestin. We also measured neoplastic endothelial cells of the mouse brain and identified 13 phosphorylated amino acid residues in the Nestin protein. Among the 11 phosphorylated amino acids of adult CNS Nestin, five (S565, S570, S819, S883, and S886) were CNS Nestin-specific phosphorylation sites. Detection of the CNS-specific phosphorylation sites in Nestin, for example, by a phospho-specific Nestin antibody, may allow the expression of CNS Nestin to be distinguished from vascular Nestin.

Namiki, Jun; Suzuki, Sayuri; Masuda, Takeshi; Ishihama, Yasushi; Okano, Hideyuki

2012-01-01

197

The Progenitors of Type Ia Supernovae  

Microsoft Academic Search

Models for Type Ia Supernovae (SNe Ia) are reviewed. It is shown that there\\u000aare strong reasons to believe that SNe Ia represent thermonuclear disruptions\\u000aof C-O white dwarfs, when these white dwarfs reach the Chandrasekhar limit and\\u000aignite carbon at their centers.\\u000a Progenitor scenarios are reviewed critically and the strengths and weaknesses\\u000aof each scenario are explicitly presented. It

MARIO LIVIO

1999-01-01

198

MAINTAINING EPITHELIOPOIETIC POTENCY WHEN CULTURING OLFACTORY PROGENITORS  

PubMed Central

The olfactory epithelium is remarkable for the persistence of multipotent, neurocompetent progenitor and stem cells throughout life that can replace all of the various cell types of the epithelium following injury. The therapeutic exploitation of the neurocompetent stem cells of the adult olfactory epithelium would be facilitated by the development of a culture system that maintains the in vivo potency of the progenitors while they are expanded and/or manipulated. We have used an air-liquid interface culture protocol, in which a feeder cell layer of 3T3 cells is established on the underside of a culture insert and FACS-isolated or unsorted progenitor cells from the methyl bromide-lesioned adult rodent epithelium are seeded on upper side. Under these conditions, epithelial cells other than HBCs are capable of organizing themselves into complex 3-dimensional, epithelium-lined spheres, which can be passaged. The spheres contain cells with the molecular phenotype of globose basal cells, horizontal basal cells, sustentacular cells and neurons. Spheres derived from mice that express the green fluorescent protein constitutively can be dissociated after 6 days in vitro and directly transplanted into the epithelium of wild type, methyl bromide-lesioned mice via nasal infusion. The resulting clones contain the various cell types observed in aggregate when globose basal cells are transplanted acutely. In contrast, the same cells cultured as two dimensional, submerged cultures undergo fibroblastic transition after transplantation and do not integrate into the epithelium. In conclusion, the culture system described here maintains the potency of progenitors, which can then participate in epitheliopoiesis in vivo.

Jang, Woochan; Lambropoulos, James; Woo, Jin Kyung; Peluso, Carolyn E.; Schwob, James E

2008-01-01

199

The interface between glial progenitors and gliomas  

Microsoft Academic Search

The mammalian brain and spinal cord contain heterogeneous populations of cycling, immature cells. These include cells with\\u000a stem cell-like properties as well as progenitors in various stages of early glial differentiation. This latter population\\u000a is distributed widely throughout gray and white matter and numerically represents an extremely large cell pool. In this review,\\u000a we discuss the possibility that the glial

Peter Canoll; James E. Goldman

2008-01-01

200

Floral Transformation of Wheat  

NASA Astrophysics Data System (ADS)

A method is described for the floral transformation of wheat using a protocol similar to the floral dip of Arabidopsis. This method does not employ tissue culture of dissected embryos, but instead pre-anthesis spikes with clipped florets at the early, mid to late uninucleate microspore stage are dipped in Agrobacterium infiltration media harboring a vector carrying anthocyanin reporters and the NPTII selectable marker. T1 seeds are examined for color changes induced in the embryo by the anthocyanin reporters. Putatively transformed seeds are germinated and the seedlings are screened for the presence of the NPTII gene based on resistance to paromomycin spray and assayed with NPTII ELISAs. Genomic DNA of putative transformants is digested and analyzed on Southern blots for copy number to determine whether the T-DNA has integrated into the nucleus and to show the number of insertions. The non-optimized transformation efficiencies range from 0.3 to 0.6% (number of transformants/number of florets dipped) but the efficiencies are higher in terms of the number of transformants produced/number of seeds set ranging from 0.9 to 10%. Research is underway to maximize seed set and optimize the protocol by testing different Agrobacterium strains, visual reporters, vectors, and surfactants.

Agarwal, Sujata; Loar, Star; Steber, Camille; Zale, Janice

201

Aneuploidy detection with a short-term hexaploid wheat assay.  

PubMed

A new type of assay for the identification of agents causing aneuploidy is described. This assay takes advantage of allohexaploid wheat in which monosomic and nullisomic cell lineages can be genetically detected. The wheat strain used (Neatby's virescens) was homozygous for a pair of recessive alleles (v1) which in homozygous condition interfere with normal pigmentation of the leaves at low temperature whereas at higher temperature nearly normal green color formation is permitted. In a single dose this allele cannot suppress the formation of green color even at low temperature, i.e., it is hemizygous ineffective. This locus is in the short arm of chromosome 3B near the centromere. As a consequence of non-disjunction of this chromosome twin sectors may be detected, in which the monosomic cell lineages appear green whereas the trisomic sectors display with color on a cream-colored background at low temperature. This genetic system can also be used for the detection of deletions or duplications involving the short arm of chromosome 3B, and to some extent the A- and the D-genome homeologues. We have determined the pattern of differentiation of the shoot apex and on that basis we can separate the independent genetic events from reappearance of the sectors of common origin in the successive leaves. Such an understanding of development of the leaf sectors permits a quantitative estimation of the genetic response of the plants to mutagenic factors. We have found that X-rays, gamma-rays, p-fluorophenylalanine, 3-aminotriazole, caffeine, vinblastin sulfate, benzo[a]pyrene and auramine significantly increased aneuploidy, and diethylstilbestrol, sulfacetamide, safrole and dichlorvos caused some increase of sectoring. Cytological data on root tips of irradiated seeds support the interpretation of the mechanism of sector formation in the leaves. The test is simple, fast, inexpensive, and it does not require elaborate facilities or highly trained technicians. The trials were well reproducible during a period of 3 years in 2 laboratories. Therefore we consider the new assay a useful complement to other tests of chemicals or physical agents that may cause non-disjunction and other chromosomal aberrations in human populations. PMID:3173382

Rédei, G P; Sandhu, S S

1988-10-01

202

RBP-J promotes the maturation of neuronal progenitors.  

PubMed

During brain development, neurons and glias are generated from neural stem cells and more limited intermediate neural progenitors (INPs). Numerous studies have revealed the mechanisms of development of neural stem cells. However, the signaling pathways that govern the development of INPs are largely unknown. The cerebellum is suitable for examining this issue because cerebellar cortical inhibitory neurons such as basket and stellate cells are derived from small Pax2(+) interneuronal progenitors. Here, we show that Sox2(-)/Pax2(+) and Sox2(+)/Pax2(-) progenitors, 2 types of interneuronal progenitors of basket and stellate cells, exist in the cerebellar white matter (WM) and that the former arise from the latter during the first postnatal week. Moreover, RBP-J promotes the neurogenesis of stellate and basket cells by converting Sox2(+)/Pax2(-) interneuronal progenitors to more mature Sox2(-)/Pax2(+) interneuronal progenitors. This study shows a novel RBP-J function that promotes INP differentiation. PMID:21443869

Komine, Okiru; Nagaoka, Mai; Hiraoka, Yuichi; Hoshino, Mikio; Kawaguchi, Yoshiya; Pear, Warren S; Tanaka, Kohichi

2011-04-02

203

Cell culture: Progenitor cells from human brain after death  

NASA Astrophysics Data System (ADS)

Culturing neural progenitor cells from the adult rodent brain has become routine and is also possible from human fetal tissue, but expansion of these cells from postnatal and adult human tissue, although preferred for ethical reasons, has encountered problems. Here we describe the isolation and successful propagation of neural progenitor cells from human postmortem tissues and surgical specimens. Although the relative therapeutic merits of adult and fetal progenitor cells still need to be assessed, our results may extend the application of these progenitor cells in the treatment of neurodegenerative diseases.

Palmer, Theo D.; Schwartz, Philip H.; Taupin, Philippe; Kaspar, Brian; Stein, Stuart A.; Gage, Fred H.

2001-05-01

204

CD133+ Renal Progenitor Cells Contribute to Tumor Angiogenesis  

PubMed Central

In the present study, we tested the hypothesis that resident progenitor cells may contribute to tumor vascularization and growth. CD133+ cells were isolated from 30 human renal carcinomas and characterized as renal resident progenitor cells on the basis of the expression of renal embryonic and mesenchymal stem cell markers. CD133+ progenitors differentiated into endothelial and epithelial cells as the normal CD133+ counterpart present in renal tissue. In the presence of tumor-derived growth factors, these cells were committed to differentiate into endothelial cells able to form vessels in vivo in SCID mice. Undifferentiated CD133+ progenitors were unable to form tumors when transplanted alone in SCID mice. When co-transplanted with renal carcinoma cells, CD133+ progenitors significantly enhanced tumor development and growth. This effect was not attributable to the tumorigenic nature of CD133+ progenitor cells because the same results were obtained with CD133+ cells from normal kidney. CD133+ progenitors contributed to tumor vascularization as the majority of neoformed vessels present within the transplanted tumors were of human origin and derived from the co-transplanted CD133+ progenitors. In conclusion, these results indicate the presence of a renal progenitor cell population in renal carcinomas that may differentiate in endothelial cells and favor vascularization and tumor growth.

Bruno, Stefania; Bussolati, Benedetta; Grange, Cristina; Collino, Federica; Efrem Graziano, Manuela; Ferrando, Ugo; Camussi, Giovanni

2006-01-01

205

63 FR 40127 - Hematopoietic Stem/Progenitor Cell Products: Discussion of Unrelated Allogeneic Placental...  

Federal Register 2010, 2011, 2012, 2013

...97N-0497] Hematopoietic Stem/Progenitor Cell Products: Discussion of Unrelated...public workshop: Hematopoietic Stem/Progenitor Cell Products: Discussion of Unrelated...umbilical cord blood hematopoietic stem/progenitor cell products; studies to...

1998-07-27

206

REGISTRATION OF 'INFINITY CL' WHEAT  

Technology Transfer Automated Retrieval System (TEKTRAN)

‘Infinity CL’ (Reg. No. Cv- ) is a hard red winter wheat (Triticum aestivum L.) cultivar developed cooperatively by the Nebraska Agricultural Experiment Station and the USDA-ARS, and released in 2005 by the developing institutions. Infinity CL contains a patented gene owned by BASF Corporation. In...

207

Wheat Genetic Resources in Nepal  

Microsoft Academic Search

Genetic diversity must be maintained and utilized for sustainable agriculture development. The amount of genetic diversity in the country depends on the number and diversity of the original ancestors involved in the creation of a germplasm pool, wild relatives and existing landraces. The objective of this research was to study the diversity of wheat gene pool present in the Nepalese

Bal K. Joshi; Ashok Mudwari; Madan R. Bhatta

2009-01-01

208

Iron Absorption from Wheat Bread  

Microsoft Academic Search

Bran is known to reduce iron absorption. There is, however, no information on the relationship between the amount of bran added and the decrease in iron absorption. In the present study a comparison was made of the iron absorption from a white wheat bread and a bread baked with different amounts of bran added (from 10 to 0.3%). There was

Erik Björn-Rasmussen

1974-01-01

209

REGISTRATION OF 'OK102' WHEAT  

Technology Transfer Automated Retrieval System (TEKTRAN)

'Ok102' is a hard red winter (HRW) wheat (Triticum aestivum L.) developed cooperatively by the Oklahoma Agricultural Experiment Station and the USDA-ARS. Ok102 was released in March 2002, primarily based on its resistance to several foliar diseases, excellent milling quality, and desirable dough st...

210

Registration of ‘Ok101’ Wheat  

Technology Transfer Automated Retrieval System (TEKTRAN)

‘Ok101’ (Reg. no. CV-932, PI 631493) is a hard red winter wheat (Triticum aestivum L.) developed cooperatively by the Oklahoma Agricultural Experiment Station and the USDA-ARS, and released in March 2001. Ok101 was released for its high tolerance to acidic soil, broad adaptation to both dual-purpose...

211

Registration of ‘Ok102’ Wheat  

Technology Transfer Automated Retrieval System (TEKTRAN)

‘Ok102’ (Reg. no. CV-941, PI 632635) is a hard red winter wheat (Triticum aestivum L.) developed cooperatively by the Oklahoma Agric. Exp. Stn. and the USDA-ARS. Ok102 was released in March 2002, primarily on the basis of its resistance to several foliar diseases, excellent milling quality, and desi...

212

Registration of ‘OK Bullet’ Wheat  

Technology Transfer Automated Retrieval System (TEKTRAN)

‘OK Bullet’ (Reg. No. CV-999, PI 642415) is a hard red winter (HRW) wheat (Triticum aestivum L.) cultivar developed cooperatively by the Oklahoma Agric. Exp. Stn. (AES), USDA-ARS, and the Texas AES and released by the Oklahoma AES and the USDA-ARS in 2005. OK Bullet is recommended for grain-only and...

213

WheatGenome.info: an integrated database and portal for wheat genome information.  

PubMed

Bread wheat (Triticum aestivum) is one of the most important crop plants, globally providing staple food for a large proportion of the human population. However, improvement of this crop has been limited due to its large and complex genome. Advances in genomics are supporting wheat crop improvement. We provide a variety of web-based systems hosting wheat genome and genomic data to support wheat research and crop improvement. WheatGenome.info is an integrated database resource which includes multiple web-based applications. These include a GBrowse2-based wheat genome viewer with BLAST search portal, TAGdb for searching wheat second-generation genome sequence data, wheat autoSNPdb, links to wheat genetic maps using CMap and CMap3D, and a wheat genome Wiki to allow interaction between diverse wheat genome sequencing activities. This system includes links to a variety of wheat genome resources hosted at other research organizations. This integrated database aims to accelerate wheat genome research and is freely accessible via the web interface at http://www.wheatgenome.info/. PMID:22009731

Lai, Kaitao; Berkman, Paul J; Lorenc, Michal Tadeusz; Duran, Chris; Smits, Lars; Manoli, Sahana; Stiller, Jiri; Edwards, David

2011-10-18

214

Circulating endothelial cells and circulating endothelial progenitors.  

PubMed

The roles of circulating endothelial cells (CECs) and circulating endothelial progenitors (CEPs) are currently being investigated in several diseases including cancer and metastases development. Preclinical and clinical data suggest that CEC enumeration might be useful to identify patients who might benefit from anti-angiogenic treatments while CEPs seem to have a "catalytic" role in different steps of cancer progression and recurrence after therapy. The definition of CEC and CEP phenotypes and the standardization of CEC and CEP enumeration procedures are highly warranted to use these cells as biomarkers in clinical trials in oncology, and to compare results from different studies. PMID:22527503

Mancuso, Patrizia; Calleri, Angelica; Bertolini, Francesco

2012-01-01

215

Circulating Endothelial Progenitor Cells, Vascular Function, and Cardiovascular Risk  

Microsoft Academic Search

background Cardiovascular risk factors contribute to atherogenesis by inducing endothelial-cell injury and dysfunction. We hypothesized that endothelial progenitor cells derived from bone marrow have a role in ongoing endothelial repair and that impaired mobilization or depletion of these cells contributes to endothelial dysfunction and cardiovascular disease progression. methods We measured the number of colony-forming units of endothelial progenitor cells in

Jonathan M. Hill; Gloria Zalos; Julian P. J. Halcox; William H. Schenke; Myron A. Waclawiw; Arshed A. Quyyumi; Toren Finkel

2009-01-01

216

Impairment of circulating endothelial progenitors in Down syndrome  

Microsoft Academic Search

BACKGROUND: Pathological angiogenesis represents a critical issue in the progression of many diseases. Down syndrome is postulated to be a systemic anti-angiogenesis disease model, possibly due to increased expression of anti-angiogenic regulators on chromosome 21. The aim of our study was to elucidate some features of circulating endothelial progenitor cells in the context of this syndrome. METHODS: Circulating endothelial progenitors

Valerio Costa; Linda Sommese; Amelia Casamassimi; Roberta Colicchio; Claudia Angelini; Valentina Marchesano; Lara Milone; Bartolomeo Farzati; Alfonso Giovane; Carmela Fiorito; Monica Rienzo; Marco Picardi; Bice Avallone; Massimiliano Marco Corsi; Berardo Sarubbi; Raffaele Calabrň; Paola Salvatore; Alfredo Ciccodicola; Claudio Napoli

2010-01-01

217

19 CFR 19.32 - Wheat manipulation; reconditioning.  

Code of Federal Regulations, 2010 CFR

...Duties 1 2009-04-01 2009-04-01 false Wheat manipulation; reconditioning. 19.32 Section...MERCHANDISE THEREIN Space Bonded for the Storage of Wheat § 19.32 Wheat manipulation; reconditioning. (a) The...

2009-04-01

218

19 CFR 19.32 - Wheat manipulation; reconditioning.  

Code of Federal Regulations, 2010 CFR

...Duties 1 2010-04-01 2010-04-01 false Wheat manipulation; reconditioning. 19.32 Section...MERCHANDISE THEREIN Space Bonded for the Storage of Wheat § 19.32 Wheat manipulation; reconditioning. (a) The...

2010-04-01

219

Alteration in expression of hormone-related genes in wild emmer wheat roots associated with drought adaptation mechanisms.  

PubMed

Transcriptomic and metabolomic profiles were used to unravel drought adaptation mechanisms in wild emmer wheat (Triticum turgidum ssp. dicoccoides), the progenitor of cultivated wheat, by comparing the response to drought stress in roots of genotypes contrasting in drought tolerance. The differences between the drought resistant (R) and drought susceptible (S) genotypes were characterized mainly by shifts in expression of hormone-related genes (e.g., gibberellins, abscisic acid (ABA) and auxin), including biosynthesis, signalling and response; RNA binding; calcium (calmodulin, caleosin and annexin) and phosphatidylinositol signalling, in the R genotype. ABA content in the roots of the R genotype was higher in the well-watered treatment and increased in response to drought, while in the S genotype ABA was invariant. The metabolomic profiling revealed in the R genotype a higher accumulation of tricarboxylic acid cycle intermediates and drought-related metabolites, including glucose, trehalose, proline and glycine. The integration of transcriptomics and metabolomics results indicated that adaptation to drought included efficient regulation and signalling pathways leading to effective bio-energetic processes, carbon metabolism and cell homeostasis. In conclusion, mechanisms of drought tolerance were identified in roots of wild emmer wheat, supporting our previous studies on the potential of this genepool as a valuable source for novel candidate genes to improve drought tolerance in cultivated wheat. PMID:21656015

Krugman, Tamar; Peleg, Zvi; Quansah, Lydia; Chagué, Véronique; Korol, Abraham B; Nevo, Eviatar; Saranga, Yehoshua; Fait, Aaron; Chalhoub, Boulos; Fahima, Tzion

2011-06-08

220

Wnt signaling regulates post-embryonic hypothalamic progenitor differentiation  

PubMed Central

Summary Previous studies have raised the possibility that Wnt signaling may regulate both neural progenitor maintenance and neuronal differentiation within a single population. Here we investigate the role of Wnt/?-catenin activity in the zebrafish hypothalamus and find that the pathway is first required for the proliferation of unspecified hypothalamic progenitors in the embryo. At later stages, including adulthood, sequential activation and inhibition of Wnt activity is required for the differentiation of neural progenitors and negatively regulates radial glia differentiation. The presence of Wnt activity is conserved in hypothalamic progenitors of the adult mouse, where it plays a conserved role in inhibiting the differentiation of radial glia. This study establishes the vertebrate hypothalamus as a model for Wnt-regulated post-embryonic neural progenitor differentiation, and defines specific roles for Wnt signaling in neurogenesis.

Wang, Xu; Kopinke, Daniel; Lin, Junji; McPherson, Adam D.; Duncan, Robert N.; Otsuna, Hideo; Moro, Enrico; Hoshijima, Kazuyuki; Grunwald, David J.; Argenton, Francesco; Chien, Chi-Bin; Murtaugh, L. Charles; Dorsky, Richard I.

2012-01-01

221

Defining and redefining the nephron progenitor population  

PubMed Central

It has long been appreciated that the mammalian kidney arises via reciprocal interactions between an epithelial ureteric epithelium and the surrounding metanephric mesenchyme. More recently, lineage tracing has confirmed that the portion of the metanephric mesenchyme closest to the advancing ureteric tips, the cap mesenchyme, represents the progenitor population for the nephron epithelia. This Six2+Cited1+ population undergoes self-renewal throughout nephrogenesis while retaining the potential to epithelialize. In contrast, the Foxd1+ portion of the metanephric mesenchyme shows no epithelial potential, developing instead into the interstitial, perivascular, and possibly endothelial elements of the kidney. The cap mesenchyme rests within a nephrogenic niche, surrounded by the stroma and the ureteric tip. While the role of Wnt signaling in nephron induction is known, there remains a lack of clarity over the intrinsic and extrinsic regulation of cap mesenchyme specification, self-renewal, and nephron potential. It is also not known what regulates cessation of nephrogenesis, but there is no nephron generation in response to injury during the postnatal period. In this review, we will examine what is and is not known about this nephron progenitor population and discuss how an increased understanding of the regulation of this population may better explain the observed variation in final nephron number and potentially facilitate the reinitiation or prolongation of nephron formation.

Hendry, Caroline; Rumballe, Bree; Moritz, Karen

2011-01-01

222

Endothelial progenitor cells: mobilization, differentiation, and homing.  

PubMed

Postnatal bone marrow contains a subtype of progenitor cells that have the capacity to migrate to the peripheral circulation and to differentiate into mature endothelial cells. Therefore, these cells have been termed endothelial progenitor cells (EPCs). The isolation of EPCs by adherence culture or magnetic microbeads has been described. In general, EPCs are characterized by the expression of 3 markers, CD133, CD34, and the vascular endothelial growth factor receptor-2. During differentiation, EPCs obviously lose CD133 and start to express CD31, vascular endothelial cadherin, and von Willebrand factor. EPCs seem to participate in endothelial repair and neovascularization of ischemic organs. Clinical studies using EPCs for neovascularization have just been started; however, the mechanisms stimulating or inhibiting the differentiation of EPC in vivo and the signals causing their migration and homing to sites of injured endothelium or extravascular tissue are largely unknown at present. Thus, future studies will help to explore areas of potential basic research and clinical application of EPCs. PMID:12714439

Hristov, Mihail; Erl, Wolfgang; Weber, Peter C

2003-04-24

223

Spatially discriminating Russian wheat aphid induced plant stress from other wheat stressing factors  

Technology Transfer Automated Retrieval System (TEKTRAN)

The Russian wheat aphid (RWA) Diuraphis noxia (Mordvilko) is a major pest of winter wheat and barley in the United States. RWA induces stress to the wheat crop by damaging plant foliage, lowering the greenness of plants, and affecting productivity. Multispectral remote sensing is effective at dete...

224

Studies on the oxidative cross-linking of feruloylated arabinoxylans from wheat flour and wheat bran  

Microsoft Academic Search

Feruloylated arabinoxylans isolated from wheat flour and wheat bran were compared in their cross-linking behaviour with respect to viscosity properties and cross-linking products formed when various oxidative agents were applied to dilute solutions. Optimal conditions for each oxidative agent were investigated. In case of hydrogen peroxide and peroxidase, similar conditions were found for both types of arabinoxylans but wheat bran

M. E. F. Schooneveld-Bergmans; M. J. W. Dignum; J. H. Grabber; G. Beldman; A. G. J. Voragen

1999-01-01

225

Mapping QTL for resistance to stripe rust in spring wheat PI 192252 and winter wheat Druchamp  

Technology Transfer Automated Retrieval System (TEKTRAN)

Stripe rust, caused by Puccinia striiformis f. sp. tritici, is an important disease of wheat worldwide. High-temperature adult-plant (HTAP) resistance has proven to be durable, but may not be adequate. Spring wheat PI 192252 and winter wheat Druchamp have high-levels of HTAP resistance. To elucidate...

226

REGISTRATION OF THREE PARTIAL WAXY WINTER WHEATS  

Technology Transfer Automated Retrieval System (TEKTRAN)

This paper describes the release of three partial (reduced amylose) waxy wheat germplasm lines: PI 617069 (96MD7413-58), PI 617070 (96MD7413-36) and PI 617071 (96MD7110-71). These partial waxy wheats carry non-functional (null) alleles (Wx-A1b, and Wx-B1b) at two of the three hexaploid wheat Wx loc...

227

Immunocytochemical localization of wheat germ agglutinin in wheat  

PubMed Central

Immunocytological techniques were developed to localize the plant lectin, wheat germ agglutinin (WGA), in the tissues and cells of wheat plants. In a previous study we demonstrated with a radioimmunoassay that the lectin is present in wheat embryos and adult plants both in the roots and at the base of the stem. We have now found, using rhodamine, peroxidase, and ferritin-labeled secondary antibodies, that WGA is located in cells and tissues that establish direct contact with the soil during germination and growth of the plant In the embryo, WGA is found in the surface layer of the radicle, the first adventitious roots, the coleoptile, and the scutellum. Although found throughout the coleorhiza and epiblast, it is at its highest levels within the cells at the surface of these organs. In adult plants, WGA is located only in the caps and tips of adventitious roots. Reaction product for WGA was not visualized in embryonic or adult leaves or in other tissues of adult plants. At the subcellular level, WGA is located at the periphery of protein bodies, within electron-translucent regions of the cytoplasm, and at the cell wall-protoplast interface. Since WGA is found at potential infection sites and is known to have fungicidal properties, it may function in the defense against fungal pathogens.

1982-01-01

228

Genetic Diversity and Linkage Disequilibrium in Chinese Bread Wheat (Triticum aestivum L.) Revealed by SSR Markers  

PubMed Central

Two hundred and fifty bread wheat lines, mainly Chinese mini core accessions, were assayed for polymorphism and linkage disequilibrium (LD) based on 512 whole-genome microsatellite loci representing a mean marker density of 5.1 cM. A total of 6,724 alleles ranging from 1 to 49 per locus were identified in all collections. The mean PIC value was 0.650, ranging from 0 to 0.965. Population structure and principal coordinate analysis revealed that landraces and modern varieties were two relatively independent genetic sub-groups. Landraces had a higher allelic diversity than modern varieties with respect to both genomes and chromosomes in terms of total number of alleles and allelic richness. 3,833 (57.0%) and 2,788 (41.5%) rare alleles with frequencies of <5% were found in the landrace and modern variety gene pools, respectively, indicating greater numbers of rare variants, or likely new alleles, in landraces. Analysis of molecular variance (AMOVA) showed that A genome had the largest genetic differentiation and D genome the lowest. In contrast to genetic diversity, modern varieties displayed a wider average LD decay across the whole genome for locus pairs with r2>0.05 (P<0.001) than the landraces. Mean LD decay distance for the landraces at the whole genome level was <5 cM, while a higher LD decay distance of 5–10 cM in modern varieties. LD decay distances were also somewhat different for each of the 21 chromosomes, being higher for most of the chromosomes in modern varieties (<5?25 cM) compared to landraces (<5?15 cM), presumably indicating the influences of domestication and breeding. This study facilitates predicting the marker density required to effectively associate genotypes with traits in Chinese wheat genetic resources.

Hao, Chenyang; Wang, Lanfen; Ge, Hongmei; Dong, Yuchen; Zhang, Xueyong

2011-01-01

229

Achieving yield gains in wheat.  

PubMed

Wheat provides 20% of calories and protein consumed by humans. Recent genetic gains are <1% per annum (p.a.), insufficient to meet future demand. The Wheat Yield Consortium brings expertise in photosynthesis, crop adaptation and genetics to a common breeding platform. Theory suggest radiation use efficiency (RUE) of wheat could be increased ~50%; strategies include modifying specificity, catalytic rate and regulation of Rubisco, up-regulating Calvin cycle enzymes, introducing chloroplast CO(2) concentrating mechanisms, optimizing light and N distribution of canopies while minimizing photoinhibition, and increasing spike photosynthesis. Maximum yield expression will also require dynamic optimization of source: sink so that dry matter partitioning to reproductive structures is not at the cost of the roots, stems and leaves needed to maintain physiological and structural integrity. Crop development should favour spike fertility to maximize harvest index so phenology must be tailored to different photoperiods, and sensitivity to unpredictable weather must be modulated to reduce conservative responses that reduce harvest index. Strategic crossing of complementary physiological traits will be augmented with wide crossing, while genome-wide selection and high throughput phenotyping and genotyping will increase efficiency of progeny screening. To ensure investment in breeding achieves agronomic impact, sustainable crop management must also be promoted through crop improvement networks. PMID:22860982

Reynolds, Matthew; Foulkes, John; Furbank, Robert; Griffiths, Simon; King, Julie; Murchie, Erik; Parry, Martin; Slafer, Gustavo

2012-08-20

230

Gfi1 integrates progenitor versus granulocytic transcriptional programming  

PubMed Central

In patients with severe congenital neutropenia (SCN) and mice with growth factor independent-1 (Gfi1) loss of function, arrested myeloid progenitors accumulate, whereas terminal granulopoiesis is blocked. One might assume that Gfi-null progenitors accumulate because they lack the ability to differentiate. Instead, our data indicate that Gfi1 loss of function deregulates 2 separable transcriptional programs, one of which controls the accumulation and lineage specification of myeloid progenitors, but not terminal granulopoiesis. We demonstrate that Gfi1 directly represses HoxA9, Pbx1, and Meis1 during normal myelopoiesis. Gfi1?/? progenitors exhibit elevated levels of HoxA9, Pbx1 and Meis1, exaggerated HoxA9-Pbx1-Meis1 activity, and progenitor transformation in collaboration with oncogenic K-Ras. Limiting HoxA9 alleles corrects, in a dose-dependent manner, in vivo and in vitro phenotypes observed with loss of Gfi1 in myeloid progenitor cells but did not rescue Gfi1?/? blocked granulopoiesis. Thus, Gfi1 integrates 2 events during normal myeloid differentiation; the suppression of a HoxA9-Pbx1-Meis1 progenitor program and the induction of a granulopoietic transcription program.

Horman, Shane R.; Velu, Chinavenmeni S.; Chaubey, Aditya; Bourdeau, Tristan; Zhu, Jinfang; Paul, William E.; Gebelein, Brian

2009-01-01

231

Type Ia Progenitor Hunt in Ancient Remnants  

NASA Astrophysics Data System (ADS)

There is broad agreement that the stars which explode as Type Ia supernovae are white dwarfs. They have accreted material in a binary system until they are near the Chandrasekhar mass and detonate/deflagrate. The two main scenarios for this accretion process are merging with a companion white dwarf (double degenerate scenario), or accretion from a main-sequence to red giant donor (single degenerate scenario). The donor star survives post-explosion and would provide substantial evidence for the single degenerate scenario, if found. Our team is analyzing stars in close proximity to Galactic Type Ia remnants to find surviving donor stars. In my talk I will introduce the different progenitor systems and the expected state for a donor star today. I will outline our search using high resolution spectroscopy and will present updated results.

Kerzendorf, Wolfgang E.

2013-01-01

232

Observing SNe Ia Progenitors with LISA  

NASA Astrophysics Data System (ADS)

The Galactic population of close white dwarf binaries is expected to provide the largest number of gravitational wave sources for low frequency detectors such as the Laser Interferometer Space Antenna (LISA). Current data analysis techniques have demonstrated the capability of resolving on the order of 104 white dwarf binaries from a 2 year observation. Resolved binaries are either at high frequencies or large amplitudes or both. Such systems are more likely to be high-mass binaries, a subset of which will be progenitors of Type Ia supernovae in the double degenerate scenario. We report on the results of a study of the properties of resolved binaries using a population synthesis model of the Galactic white dwarf binaries and a LISA data analysis algorithm using Mock LISA Data Challenge tools.

Ceballos, Frank; Stroeer, A.; Benacquista, M.; Belczynski, K.

2012-01-01

233

Galaxies, their satellites and progenitors: chemical properties  

NASA Astrophysics Data System (ADS)

We use a model that combines N-body cosmological simulations of galaxy clusters and a semi-analytic model of galaxy formation (SAG: Semi-analytical galaxies; Lagos, Cora & Padilla, 2008) in order to study the properties of galaxy progenitors, using the information provided by their stellar haloes, and surviving satellites at redshift z = 0. We model the formation of stellar haloes by considering tidal stripping events acting on the satellite galaxies before the mergers occur, being able to follow their mass, luminosity and chemical properties. We find that the satellite galaxies have lower metal- licities than the stellar haloes of central galaxies for a given host DM halo mass, as has been already noted by Lagos, Padilla & Cora (2009), using a different approach.

Gargiulo, I.; Cora, S. A.; Padilla, N. D.

234

PET imaging of adoptive progenitor cell therapies.  

SciTech Connect

Objectives. The overall objective of this application is to develop novel technologies for non-invasive imaging of adoptive stem cell-based therapies with positron emission tomography (PET) that would be applicable to human patients. To achieve this objective, stem cells will be genetically labeled with a PET-reporter gene and repetitively imaged to assess their distribution, migration, differentiation, and persistence using a radiolabeled reporter probe. This new imaging technology will be tested in adoptive progenitor cell-based therapy models in animals, including: delivery pro-apoptotic genes to tumors, and T-cell reconstitution for immunostimulatory therapy during allogeneic bone marrow progenitor cell transplantation. Technical and Scientific Merits. Non-invasive whole body imaging would significantly aid in the development and clinical implementation of various adoptive progenitor cell-based therapies by providing the means for non-invasive monitoring of the fate of injected progenitor cells over a long period of observation. The proposed imaging approaches could help to address several questions related to stem cell migration and homing, their long-term viability, and their subsequent differentiation. The ability to image these processes non-invasively in 3D and repetitively over a long period of time is very important and will help the development and clinical application of various strategies to control and direct stem cell migration and differentiation. Approach to accomplish the work. Stem cells will be genetically with a reporter gene which will allow for repetitive non-invasive “tracking” of the migration and localization of genetically labeled stem cells and their progeny. This is a radically new approach that is being developed for future human applications and should allow for a long term (many years) repetitive imaging of the fate of tissues that develop from the transplanted stem cells. Why the approach is appropriate. The novel approach to stem cell imaging is proposed to circumvent the major limitation of in vitro radiolabeling – the eventual radiolabel decay. Stable transduction of stem cells in vitro would allow for the selection of high quality stem cells with optimal functional parameters of the transduced reporter systems. The use of a long-lived radioisotope 124I to label a highly specific reporter gene probe will allow for ex vivo labeling of stem cells and their imaging immediately after injection and during the following next week. The use of short-lived radioisotopes (i.e., 18F) to label highly specific reporter gene probes will allow repetitive PET imaging for the assessment of to stem cell migration, targeting, differentiation, and long-term viability of stem cell-derived tissues. Qualifications of the research team and resources. An established research team of experts in various disciplines has been assembled at MD Anderson Cancer Center (MDACC) over the past two years including the PI, senior co-investigators and collaborators. The participants of this team are recognized internationally to be among the leaders in their corresponding fields of research and clinical medicine. The resources at MDACC are exceptionally well developed and have been recently reinforced by the installation of a microPET and microSPECT/CT cameras, and a 7T MRI system for high resolution animal imaging; and by integrating a synthetic chemistry core for the development and production of precursors for radiolabeling.

Gelovani, Juri G.

2008-05-13

235

Circulating Apoptotic Progenitor Cells in Patients with Congestive Heart Failure  

PubMed Central

Background Circulating CD34+ endothelial progenitor cells (EPCs) are capable of differentiating into mature endothelial cells to assist in angiogenesis and vasculogenesis. We sought to quantify the numbers of apoptotic progenitors in patients with congestive heart failure. Methods and Results Peripheral blood mononuclear cells were isolated by Ficoll density-gradient from 58 patients with various degrees of heart failure and 23 matched controls. Apoptosis in progenitor CD34+ cells was assessed using the Annexin V-PE/PI detection kit, and FACS analysis was performed with triple staining for CD34, annexin-V and propidium iodide. The percentage of early and late apoptotic progenitor cells was determined in the subject groups and was correlated with clinical characteristics. While there was no significant difference in total CD34 positive cells or early apoptotic progenitors between control subjects and CHF patients (p?=?0.42) or between severe and mild/moderate CHF groups (p?=?0.544), there was an elevated number of late apoptotic progenitors in the severe CHF group compared with the mild/moderate CHF group (p?=? 0.03). Late apoptotic progenitors were significantly increased in CHF patients as compared to matched controls. There was also an inverse correlation between late apoptotic progenitors and ejection fraction (r?=??0.252, p?=?0.028) as well as a positive association with NYHA class (r?=?0.223, p?=?0.046). Conclusion Severe heart failure patients exhibited higher numbers of late apoptotic progenitors, and this was positively associated with NYHA class and negatively correlated with ejection fraction. This finding may shed light on the numerous factors governing the pathophysiology of CHF.

Rogowsky, Ori; Finkelstein, Ariel; Ablin, Jacob; Maysel-Auslender, Sofia; Wexler, Dov; Keren, Gad; George, Jacob

2008-01-01

236

Integrin Profile and In Vivo Homing of Human Smooth Muscle Progenitor Cells  

Microsoft Academic Search

Background—Recently, we identified circulating smooth muscle progenitor cells (SPCs) in human peripheral blood. The integrin profile of such progenitors is currently unknown and may affect their in vivo homing characteristics. In this study, we determined the integrin profile of vascular progenitors and SPC adhesion to extracellular matrix (ECM) proteins in vitro and in vivo. Methods and Results—SPCs and endothelial progenitor

Arjun Deb; Kimberly A. Skelding; Shaohua Wang; Margo Reeder; David Simper; Noel M. Caplice

237

A COMPREHENSIVE PROGENITOR MODEL FOR SNe Ia  

SciTech Connect

Although the nature of the progenitor of Type Ia supernovae (SNe Ia) is still unclear, the single-degenerate (SD) channel for the progenitor is currently accepted, in which a carbon-oxygen white dwarf (CO WD) accretes hydrogen-rich material from its companion, increases its mass to the Chandrasekhar mass limit, and then explodes as an SN Ia. The companion may be a main sequence or a slightly evolved star (WD + MS), or a red giant star (WD + RG). Incorporating the effect of mass stripping and accretion-disk instability on the evolution of the WD binary, we carried out binary stellar evolution calculations for more than 1600 close WD binaries. As a result, the initial parameter spaces for SNe Ia are presented in an orbital period-secondary mass (log P{sub i}, M {sup i}{sub 2}) plane. We confirmed that in a WD + MS system, the initial companion leading to SNe Ia may have mass from 1 M{sub sun} to 5 M{sub sun}. The initial WD mass for SNe Ia from WD + MS channel is as low as 0.565 M{sub sun}, while the lowest WD mass from the WD + RG channel is 1.0 M{sub sun}. Adopting the above results, we studied the birth rate of SNe Ia via a binary population synthesis approach. We found that the Galactic SNe Ia birth rate from SD model is (2.55-2.9) x 10{sup -3} yr{sup -1} (including WD + He star channel), which is slightly smaller than that from observation. If a single starburst is assumed, the distribution of the delay time of SNe Ia from the SD model may be a weak bimodality, where WD + He channel contributes to SNe Ia with delay time shorter than 10{sup 8} yr and WD + RG channel to those with age longer than 6 Gyr.

Meng, X.; Yang, W., E-mail: xiangcunmeng@hotmail.co [School of Physics and Chemistry, Henan Polytechnic University, Jiaozuo, 454000 (China)

2010-02-20

238

Testing SN IA progenitor scenarios: SNR 1006  

NASA Astrophysics Data System (ADS)

For Type Ia supernovae several progenitor scenarios have been proposed: 1) Roche lobe overflow from main sequence stars onto white dwarfs, 2) Roche lobe overflow from subgiants onto white dwarfs, 3) Wind accretion from a giant companion 4) Merging white dwarf pairs. So far, none of these scenarios have been clearly demonstrated to occur in nature, and only for scenario 1 we know potential observed counterparts, the supersoft X-ray sources. We have computed detailed evolutionary model grids for scenarios 1 and 2, and relied on literature data for scenario 3, in order to determine the properties of the white dwarf companion star at the time of the supernova explosion. E.g., we found that the companions in scenario 1 stem from 1.7 dots 2.3 M_odot main sequence stars and are underluminous stars of more than 1 M_odot, out of thermal equilibrium, with luminosities in the range 1 dots 10 L_odot, devoid of Li, Be, and B, and partly enriched in carbon. Scenarios 2 and 3 are found to leave low mass O or B subdwarfs. From Scenarios 1 and 2, we expect large space velocities for the companions after the white dwarf explosion (100 dots 1000 km/s). The remnant of the historical Type Ia supernova SN 1006 is close enough to unambiguously identify the former companion star of the white dwarf and, according to its properties, distinguish between scenarios 1, 2 and 3. We propose a detailed observational strategy to find the companion star. The sdO star near the center of SN 1006 has already been investigated in part. A failure of finding any suitable star in SNR 1006 would support scenario 4. In any case, a distinctive test of Type Ia supernova progenitor scenarios appears to be possible with SNR 1006.

Wellstein, S.; Langer, N.; Gehren, T.; Burleigh, M.; Heber, U.

239

In vitro toxicity of trichothecenes on human haematopoietic progenitors.  

PubMed

The culture of human haematopoietic progenitors, Colony-Forming-Unit Granulocyte and Macrophage (CFU-GM), has been performed in the presence of four trichothecenes, T-2 toxin, HT-2 toxin, diacetoxyscirpenol (DAS), and deoxynivalenol (DON). Our results showed that trichothecenes were cytotoxic for human haematopoietic progenitors. This work and the analysis of results described in the literature allowed us to propose that the haematologic lesions observed during human intoxication could be due to a destruction of haematopoietic progenitors such as granulocytic and macrophage colony-forming cells. PMID:7958114

Parent-Massin, D; Fuselier, R; Thouvenot, D

240

Climate variability and wheat baking quality  

Microsoft Academic Search

The influence of climatic factors on the baking quality of bread wheat was explored by establishing relationships between Mechanical Dough Development (MDD) bake scores and monthly temperature and rainfall from November to January. Wheat quality data for Triticum aestivum L. cultivars ‘Rongotea’, ‘Oroua’, and ‘Otane’ were collated from recommended list trials in Hawke's Bay, Manawatu, Canterbury, south Otago, and Southland,

M. J. Salinger; P. D. Jamieson; J. V. Johnstone

1995-01-01

241

Deoxyribonucleic Acid and the Ancestry of Wheat  

Microsoft Academic Search

REES1 has suggested that data relating to the DNA content of nuclei may provide a further clue regarding the parental composition of allopolyploid plants like durum and bread wheats. From Rees's results1 it is clear that Aegilops speltoides is more likely to be the donor of the B genome of tetraploid wheat than the other members of the Sitopsis section

M. D. Upadhya; M. S. Swaminathan

1963-01-01

242

Managing Buffer Stocks to Stabilize Wheat Prices.  

National Technical Information Service (NTIS)

A wheat buffer stock simulation model is used to add random deviations of wheat yields and exports to projected supply and demand conditions for 1976-82. The result is a useful analytical tool for policy analysis-especially for the analysis of questions a...

J. A. Sharples R. L. Walker R. W. Slaughter

1976-01-01

243

Paint removal using wheat starch blast media  

Microsoft Academic Search

A review of the Wheat Starch Blasting technology is presented. Laboratory evaluations covering Almen Arc testing on bare 2024-T3 aluminum and magnesium, as well as crack detection on 7075-T6 bare aluminum, are discussed. Comparisons with Type V plastic media show lower residual stresses are achieved on aluminum and magnesium with wheat starch media. Dry blasting effects on the detection of

Terry Foster; John Oestreich

1993-01-01

244

Determinants of Wheat Import Demand: Tunisia.  

National Technical Information Service (NTIS)

Tunisia has the world's highest per capita consumption of wheat and is representative of growing cereal markets in North Africa and the Middle East. It is not a leader in terms of total volume of wheat imports, being virtually self-sufficient in durum whe...

R. Lent E. Dusch

1994-01-01

245

IMPACT OF OZONE ON WINTER WHEAT YIELD  

EPA Science Inventory

Wheat is one of the more important agricultural crops in the USA, and the major production areas may be subjected to potentially damaging concentrations of ozone (O3). Since no information was available regarding the O3 sensitivity of winter wheat cultivars grown in the Midwest, ...

246

THE WHEAT (TRITICUM AESTIVUM L.) LEAF PROTEOME  

Technology Transfer Automated Retrieval System (TEKTRAN)

The wheat leaf proteome was mapped and partially characterized to function as a comparative template for future wheat research. In total, 404 proteins were visualized, and 277 of these were selected for analysis based on reproducibility and relative quantity. Using a combination of protein and exp...

247

Herbicidal effects of soil-incorporated wheat.  

PubMed

The hydroxamic acid 2,4-dihydroxy-7-methoxy-1,4-benzoxazin-3-one (DIMBOA) and the benzoxazolinones benzoxazolin-2-one (BOA) and 6-methoxybenzoxazolin-2-one (MBOA) have been identified as important allelochemicals in wheat. This study examines the possibility of exploiting the allelopathic properties of wheat as a weed control strategy by cultivating wheat as a precrop and incorporating plant residues into the soil before the next crop is sown. Different wheat varieties were cultivated in field plots during two seasons in both conventional and organic farming systems. Plants were sampled at various growth stages, and their contents of DIMBOA, MBOA, and BOA were determined by chemical analyses. The wheat samples were incorporated into soil, and the effect on germination and growth of 12 different weed species was examined in pot experiments under controlled conditions. In some cases significant effects were obtained, but the results were inconsistent and the effects were not correlated to the content of DIMBOA, MBOA, and BOA in the incorporated wheat plants. ED50 doses of the pure compounds were estimated in dose-response experiments in Petri dishes, and these turned out to be much higher than the predicted maximum concentrations of DIMBOA, MBOA, and BOA in the soil water following incorporation. The study shows that a prerequisite for exploiting the incorporation of wheat residues as a weed control strategy is the development of wheat varieties with an increased content of allelochemicals. PMID:16478217

Mathiassen, Solvejg K; Kudsk, Per; Mogensen, Betty B

2006-02-22

248

Product Differentiation in Wheat Trade Modeling.  

National Technical Information Service (NTIS)

Economic research described in the report indicates that wheat should be differentiated by end use and by country of origin for trade policy modeling. The study uses wheat market information gathered as part of the international component of the grain qua...

S. L. Haley

1995-01-01

249

Biodegradability of wheat gluten based bioplastics  

Microsoft Academic Search

A large variety of wheat gluten based bioplastics, which were plasticized with glycerol, were subjected to biodegradation. The materials covered the total range available for the biochemical control parameter Fi, which expresses the percentage of aggregated proteins. This quantity can be related to the density of covalent crosslinks in the wheat gluten network, which are induced by technological treatments. The

Sandra Domenek; Pierre Feuilloley; Jean Gratraud; Marie-Hélčne Morel; Stéphane Guilbert

2004-01-01

250

Sunflower phytochemicals adversely affect wheat yield.  

PubMed

Various researchers have reported the weedicidal potential of sunflower when used as incorporation, mulch or aqueous extract without noticing its effect on crop. This study was planned to investigate the harmful effects of sunflower phytochemicals on wheat varieties. Early laboratory experiments were performed on four wheat varieties, i.e. Inqlab-91, Punjab-96, Pasban-90 and Uqab-2000. The aqueous extract of three sunflower varieties tested against wheat varieties significantly decreased biomass of wheat seedlings, especially at concentrations of 40% and 50%. However, wheat variety Punjab-96 resisted the most, which was selected for further trials. This detrimental effect was also noticed in pot trials, the extent of which varied with the age of the wheat seedlings and number of sprays. Three early sprays with one week intervals showed maximum losses to the crop plant. The study suggests the use of sunflower extracts for the management of weeds that emerge 3-4 weeks after wheat seedlings. However, the study discourages the use of sunflower mulch or incorporation in wheat fields for weed management. PMID:20461628

Anjum, Tehmina; Bajwa, Rukhsana

2010-05-01

251

TRACKING WHEAT RUST ON A CONTINENTAL SCALE  

Technology Transfer Automated Retrieval System (TEKTRAN)

The rusts of wheat are important fungal plant pathogens that can be wind disseminated for thousands of kilometers across continents and oceans. Rusts are obligate parasites that interact with resistance genes in wheat in a gene-for-gene manner. New races of rust develop by mutation and selection for...

252

Chapter 6: Floral Transformation of Wheat  

Technology Transfer Automated Retrieval System (TEKTRAN)

Hexaploid wheat is one of the world’s most important staple crops but genetic transformation is still challenging. We are developing a floral transformation protocol for wheat that does not require tissue culture. Several T-DNA transformants have been produced in the high quality, hard red germpla...

253

21 CFR 184.1322 - Wheat gluten.  

Code of Federal Regulations, 2013 CFR

...Wheat gluten (CAS Reg. No. 8002-80-0) is the principal protein component of wheat and consists mainly of gliadin and...Vital gluten is dried gluten that has retained its elastic properties. (b) The ingredient must be of a purity suitable...

2013-04-01

254

Annotated Compendium of Wheat Diseases in India.  

National Technical Information Service (NTIS)

This Compendium has brought together under one cover all available information on wheat diseases up to 1975. It also includes a review of the work done in India on wheat diseases until 1975, followed by detailed abstracts of Indian publications arranged a...

L. M. Joshi K. D. ivastava D. V. Singh L. B. Goel S. Nagarajan

1978-01-01

255

DIATOMACEOUS EARTH SURFACE TREATMENT FOR STORED WHEAT  

Technology Transfer Automated Retrieval System (TEKTRAN)

Diatomaceous earth (DE) can be used as a surface treatment in stored wheat to control pest infestations. However, it is not known how the thickness of the DE-treated wheat layer or grain temperature impacts effectiveness. When adult Rhizopertha dominica (F.), lesser grain borers, were released in e...

256

Research Status Quo and Future of Low Temperature Wheat Genotypes  

Microsoft Academic Search

Low temperature wheat genotypes are a group of wheat with a slightly low canopy (plant) temperature, and the research on their biological characters and utilization in wheat breeding has been done at home and abroad for more than 20 years, and has made great progress. The research contents and advances include the following respects: Wheat genotypes with slightly low canopy

Song-wu ZHANG; Chang-fa WANG

2008-01-01

257

THE PERFORMANCE OF AGRICULTURAL MARKET ADVISORY SERVICES IN MARKETING WHEAT  

Microsoft Academic Search

The purpose of this paper is to investigate the performance of agricultural market advisory services in marketing wheat. Two key performance questions are addressed: 1) Do market advisory services, on average, outperform an appropriate wheat market benchmark? and 2) Do market advisory services exhibit persistence in their wheat performance from year-to-year? Market advisory service recommendations for wheat are available from

Mark A. Jirik; Scott H. Irwin; Darrel L. Good; Thomas E. Jackson; Joao Martines-Filho

2000-01-01

258

Economic Implications of Cleaning Wheat in the United States.  

National Technical Information Service (NTIS)

The costs of cleaning wheat exceed the domestic benefits of cleaning wheat. The absence of net domestic benefits from cleaning wheat suggests that the U.S. wheat market is responding efficiently to domestic market signals for less dockage and foreign mate...

B. T. Hyberg M. Ash W. Lin C. Lin L. Aldrich

1993-01-01

259

ISSUES IN DEVELOPMENT AND ADOPTION OF GENETICALLY MODIFIED (GM) WHEATS  

Microsoft Academic Search

Development of genetically modified (GM) wheat varieties is proceeding; however, several critical issues remain the focus of contention. This project summarizes the current state of knowledge on some of these critical issues for commercialization of GM wheats. Background on the evolution of GM Wheats is presented. Then, agronomic adoption and competitiveness of GM crops; research on GM traits in wheat;

William W. Wilson; Edward L. Janzen; Bruce L. Dahl; Cheryl J. Wachenheim

2003-01-01

260

Phospholipase A2 activity during cold acclimation of wheat  

Technology Transfer Automated Retrieval System (TEKTRAN)

Phospholipase A2 (EC 3.1.1.4; PLA2) activity in wheat (Triticum aestivum L.) crown tissue from plants undergoing cold acclimation and/or chilling stress was investigated in a moderately cold tolerant winter wheat, a spring wheat, and a poorly cold tolerant winter wheat. Activity levels were inv...

261

Wheat ?-amylase inhibitor: A second route of allergic sensitization  

Microsoft Academic Search

Background: Low molecular weight allergens may be responsible for hypersensitivity reactions after the ingestion of wheat. Objective: The purpose of this investigation was to identify relevant, low molecular weight allergens after the ingestion of wheat protein. Methods: Serum samples were collected from seven children with wheat allergy and one adult with baker's asthma. Control serum samples were collected from wheat-tolerant

John M. James; J. Patrick Sixbey; Ricki M. Helm; Gary A. Bannon; A. Wesley Burks

1997-01-01

262

Genes encoding 4-Cys antimicrobial peptides in wheat Triticum kiharae Dorof. et Migush.: multimodular structural organization, instraspecific variability, distribution and role in defence.  

PubMed

A novel family of antifungal peptides was discovered in the wheat Triticum kiharae Dorof. et Migusch. Two members of the family, designated Tk-AMP-X1 and Tk-AMP-X2, were completely sequenced and shown to belong to the ?-hairpinin structural family of plant peptides with a characteristic C1XXXC2-X(n)-C3XXXC4 motif. The peptides inhibit the spore germination of several fungal pathogens in vitro. cDNA and gene cloning disclosed unique structure of genes encoding Tk-AMP-X peptides. They code for precursor proteins of unusual multimodular structure, consisting of a signal peptide, several ?-hairpinin (4-Cys) peptide domains with a characteristic cysteine pattern separated by linkers and a C-terminal prodomain. Three types of precursor proteins, with five, six or seven 4-Cys peptide modules, were found in wheat. Among the predicted family members, several peptides previously isolated from T. kiharae seeds were identified. Genes encoding Tk-AMP-X precursors have no introns in the protein-coding regions and are upregulated by fungal pathogens and abiotic stress, providing conclusive evidence for their role in stress response. A combined PCR-based and bioinformatics approach was used to search for related genes in the plant kingdom. Homologous genes differing in the number of peptide modules were discovered in phylogenetically-related Triticum and Aegilops species, including polyploid wheat genome donors. Association of the Tk-AMP-X genes with A, B/G or D genomes of hexaploid wheat was demonstrated. Furthermore, Tk-AMP-X-related sequences were shown to be widespread in the Poaceae family among economically important crops, such as barley, rice and maize. PMID:23702306

Utkina, Lyubov L; Andreev, Yaroslav A; Rogozhin, Eugene A; Korostyleva, Tatyana V; Slavokhotova, Anna A; Oparin, Peter B; Vassilevski, Alexander A; Grishin, Eugene V; Egorov, Tsezi A; Odintsova, Tatyana I

2013-06-18

263

He-accreting WDs as SNe Ia Progenitors  

NASA Astrophysics Data System (ADS)

We investigate the thermal response of CO WDs accreting He-rich matter directly from their companions in binary systems. Our results suggest that the He-channel cannot provide progenitors for the majority of ``normal'' SNe Ia.

Piersanti, Luciano; Tornambé, Amedeo; Yungelson, Lev; Straniero, Oscar

2013-01-01

264

The Adventitia: A Progenitor Cell Niche for the Vessel Wall  

PubMed Central

Recent observations suggest that the adventitial layer of blood vessels exhibits properties resembling a stem/progenitor cell niche. Progenitor cells have been isolated from the adventitia of both murine and human blood vessels with the potential to form endothelial cells, mural cells, osteogenic cells, and adipocytes. These progenitors appear to cluster at or near the border zone between the outer media and inner adventitia. In the mouse, this border zone region corresponds to a localized site of sonic hedgehog signaling in the artery wall. This brief review will discuss the emerging evidence that the tunica adventitia may provide a niche-like signaling environment for resident progenitor cells and will address the role of the adventitia in growth, remodeling, and repair of the artery wall.

Majesky, Mark W.; Dong, Xiu Rong; Hoglund, Virginia; Daum, Gunter; Mahoney, William M.

2011-01-01

265

Developmental and Regenerative Biology of Multipotent Cardiovascular Progenitor Cells  

PubMed Central

Our limited ability to improve the survival of patients with heart failure is due, in part, to the inability of the mammalian heart to meaningfully regenerate itself. The recent identification of distinct families of multipotent cardiovascular progenitor cells from endogenous as well as exogenous sources, such as embryonic and induced pluripotent stem cells, has raised much hope that therapeutic manipulation of these cells may lead to regression of many forms of cardiovascular disease. While the exact source and cell type remains to be clarified, our greater understanding of the scientific underpinning behind developmental cardiovascular progenitor cell biology has helped to clarify the origin and properties of diverse cells with putative cardiogenic potential. In this review, we highlight recent advances in the understanding of cardiovascular progenitor cell biology from embryogenesis to adulthood and their implications for therapeutic cardiac regeneration. We believe that a detailed understanding of cardiogenesis will inform future applications of cardiovascular progenitor cells in heart failure therapy and regenerative medicine.

Sturzu, Anthony C.; Wu, Sean M.

2011-01-01

266

Developmental and regenerative biology of multipotent cardiovascular progenitor cells.  

PubMed

Our limited ability to improve the survival of patients with heart failure is attributable, in part, to the inability of the mammalian heart to meaningfully regenerate itself. The recent identification of distinct families of multipotent cardiovascular progenitor cells from endogenous, as well as exogenous, sources, such as embryonic and induced pluripotent stem cells, has raised much hope that therapeutic manipulation of these cells may lead to regression of many forms of cardiovascular disease. Although the exact source and cell type remains to be clarified, our greater understanding of the scientific underpinning behind developmental cardiovascular progenitor cell biology has helped to clarify the origin and properties of diverse cells with putative cardiogenic potential. In this review, we highlight recent advances in the understanding of cardiovascular progenitor cell biology from embryogenesis to adulthood and their implications for therapeutic cardiac regeneration. We believe that a detailed understanding of cardiogenesis will inform future applications of cardiovascular progenitor cells in heart failure therapy and regenerative medicine. PMID:21293007

Sturzu, Anthony C; Wu, Sean M

2011-02-01

267

Stromal-epithelial crosstalk regulates kidney progenitor cell differentiation.  

PubMed

Present models suggest that the fate of the kidney epithelial progenitors is solely regulated by signals from the adjacent ureteric bud. The bud provides signals that regulate the survival, renewal and differentiation of these cells. Recent data suggest that Wnt9b, a ureteric-bud-derived factor, is sufficient for both progenitor cell renewal and differentiation. How the same molecule induces two seemingly contradictory processes is unknown. Here, we show that signals from the stromal fibroblasts cooperate with Wnt9b to promote differentiation of the progenitors. The atypical cadherin Fat4 encodes at least part of this stromal signal. Our data support a model whereby proper kidney size and function is regulated by balancing opposing signals from the ureteric bud and stroma to promote renewal and differentiation of the nephron progenitors. PMID:23974041

Das, Amrita; Tanigawa, Shunsuke; Karner, Courtney M; Xin, Mei; Lum, Lawrence; Chen, Chuo; Olson, Eric N; Perantoni, Alan O; Carroll, Thomas J

2013-08-25

268

Delineating the structural, functional and evolutionary relationships of sucrose phosphate synthase gene family II in wheat and related grasses  

PubMed Central

Background Sucrose phosphate synthase (SPS) is an important component of the plant sucrose biosynthesis pathway. In the monocotyledonous Poaceae, five SPS genes have been identified. Here we present a detailed analysis of the wheat SPSII family in wheat. A set of homoeologue-specific primers was developed in order to permit both the detection of sequence variation, and the dissection of the individual contribution of each homoeologue to the global expression of SPSII. Results The expression in bread wheat over the course of development of various sucrose biosynthesis genes monitored on an Affymetrix array showed that the SPS genes were regulated over time and space. SPSII homoeologue-specific assays were used to show that the three homoeologues contributed differentially to the global expression of SPSII. Genetic mapping placed the set of homoeoloci on the short arms of the homoeologous group 3 chromosomes. A resequencing of the A and B genome copies allowed the detection of four haplotypes at each locus. The 3B copy includes an unspliced intron. A comparison of the sequences of the wheat SPSII orthologues present in the diploid progenitors einkorn, goatgrass and Triticum speltoides, as well as in the more distantly related species barley, rice, sorghum and purple false brome demonstrated that intronic sequence was less well conserved than exonic. Comparative sequence and phylogenetic analysis of SPSII gene showed that false purple brome was more similar to Triticeae than to rice. Wheat - rice synteny was found to be perturbed at the SPS region. Conclusion The homoeologue-specific assays will be suitable to derive associations between SPS functionality and key phenotypic traits. The amplicon sequences derived from the homoeologue-specific primers are informative regarding the evolution of SPSII in a polyploid context.

2010-01-01

269

Vascular Calcifying Progenitor Cells Possess Bidirectional Differentiation Potentials  

PubMed Central

Vascular calcification is an advanced feature of atherosclerosis for which no effective therapy is available. To investigate the modulation or reversal of calcification, we identified calcifying progenitor cells and investigated their calcifying/decalcifying potentials. Cells from the aortas of mice were sorted into four groups using Sca-1 and PDGFR? markers. Sca-1+ (Sca-1+/PDGFR?+ and Sca-1+/PDGFR??) progenitor cells exhibited greater osteoblastic differentiation potentials than Sca-1? (Sca-1?/PDGFR?+ and Sca-1?/PDGFR??) progenitor cells. Among Sca-1+ progenitor populations, Sca-1+/PDGFR?? cells possessed bidirectional differentiation potentials towards both osteoblastic and osteoclastic lineages, whereas Sca-1+/PDGFR?+ cells differentiated into an osteoblastic lineage unidirectionally. When treated with a peroxisome proliferator activated receptor ? (PPAR?) agonist, Sca-1+/PDGFR?? cells preferentially differentiated into osteoclast-like cells. Sca-1+ progenitor cells in the artery originated from the bone marrow (BM) and could be clonally expanded. Vessel-resident BM-derived Sca-1+ calcifying progenitor cells displayed nonhematopoietic, mesenchymal characteristics. To evaluate the modulation of in vivo calcification, we established models of ectopic and atherosclerotic calcification. Computed tomography indicated that Sca-1+ progenitor cells increased the volume and calcium scores of ectopic calcification. However, Sca-1+/PDGFR?? cells treated with a PPAR? agonist decreased bone formation 2-fold compared with untreated cells. Systemic infusion of Sca-1+/PDGFR?? cells into Apoe?/? mice increased the severity of calcified atherosclerotic plaques. However, Sca-1+/PDGFR?? cells in which PPAR? was activated displayed markedly decreased plaque severity. Immunofluorescent staining indicated that Sca-1+/PDGFR?? cells mainly expressed osteocalcin; however, activation of PPAR? triggered receptor activator for nuclear factor-?B (RANK) expression, indicating their bidirectional fate in vivo. These findings suggest that a subtype of BM-derived and vessel-resident progenitor cells offer a therapeutic target for the prevention of vascular calcification and that PPAR? activation may be an option to reverse calcification.

Lee, Ho-Jae; Song, Myung-Kang; Seo, Ji-Yun; Bae, Yeon-Hee; Kim, Ju-Young; Lee, Hae-Young; Lee, Whal; Koo, Bon-Kwon; Oh, Byung-Hee; Park, Young-Bae; Kim, Hyo-Soo

2013-01-01

270

Genetic Analysis of Lrp5 Function in Osteoblast Progenitors  

Microsoft Academic Search

The low-density lipoprotein receptor-related protein (Lrp)-5 regulates osteoblast proliferation and bone formation through\\u000a its expression in duodenum by modifying the gut serotonin–bone endocrine axis. However, its direct role, if any, in osteoblast\\u000a progenitor cells has not been studied thus far. Here, we show that mice with a Dermo1-Cre-mediated disruption of Lrp5 in osteoblast progenitor cells have normal embryonic skeletogenesis and

Vijay K. Yadav; Henrique Pierotti Arantes; Elizabete Ribeiro Barros; Marise Lazaretti-Castro; Patricia Ducy

2010-01-01

271

Isolation of Human Oral Keratinocyte Progenitor\\/Stem Cells  

Microsoft Academic Search

Progenitor\\/stem cell populations of epithelium are known to reside in the small-sized cell population. Our objective was to physically isolate and characterize an oral keratinocyte-enriched population of small-sized progenitor\\/stem cells. Primary human oral mucosal keratinocytes cultured in a chemically defined serum-free culture system, devoid of animal-derived feeder cells, were sorted by relative cell size and characterized by immunolabeling for ?1

K. Izumi; T. Tobita; S. E. Feinberg

2007-01-01

272

Red blood cell production from immortalized progenitor cell line  

Microsoft Academic Search

The supply of transfusable red blood cells (RBCs) is not sufficient in many countries. If immortalized erythroid progenitor\\u000a cell lines able to produce transfusable RBCs in vitro were established, they would be valuable resources. However, such cell\\u000a lines have not been established. We have developed a robust method to establish immortalized erythroid progenitor cell lines\\u000a following the induction of hematopoietic

Yukio Nakamura; Takashi Hiroyama; Kenichi Miharada; Ryo Kurita

2011-01-01

273

Dissecting the Molecular Relationship Among Various Cardiogenic Progenitor Cells  

PubMed Central

Rationale Multiple progenitors derived from the heart and bone marrow have been utilized for cardiac repair. Despite this, not much is known about the molecular identity and relationship among these progenitors. To develop a robust stem cell therapy for the heart, it is critical to understand the molecular identity of the multiple ‘cardiogenic progenitor cells’ (CPCs). This study is the first report of high throughput transcriptional profiling of CPCs carried out on an identical platform. Method and Results Microarray based transcriptional profiling was carried out for three cardiac (ckit+, Sca1+, side population) and two bone marrow (ckit+ , mesenchymal stem cell) progenitors, obtained from age- and sex-matched wild type C57BL/6 mice. Analysis indicated that cardiac-derived ckit+ population was very distinct from Sca1+ and SP cells in the downregulation of genes encoding for cell-cell and matrix adhesion proteins, and in the upregulation of developmental genes. Significant enrichment of transcripts involved in DNA replication and repair was observed in bone marrow (BM)-derived progenitors. The BM ckit+ cells appeared to have the least correlation with the other progenitors, with enrichment of immature neutrophil specific molecules. Conclusion Our study indicates that cardiac ckit+ cells represent the most primitive population in the rodent heart. Primitive cells of cardiac versus BM origin differ significantly with respect to stemness and cardiac lineage-specific genes, and molecules involved in DNA replication and repair. The detailed molecular profile of progenitors reported here will serve as a useful reference to determine the molecular identity of progenitors used in future preclinical and clinical studies

Dey, Devaveena; Han, Leng; Bauer, Michael; Sanada, Fumihiro; Oikonomopoulos, Angelos; Hosoda, Toru; Unno, Kazumasa; De Almeida, Patricia; Leri, Annarosa; Wu, Joseph C.

2013-01-01

274

LINKING TYPE Ia SUPERNOVA PROGENITORS AND THEIR RESULTING EXPLOSIONS  

SciTech Connect

Comparing the ejecta velocities at maximum brightness and narrow circumstellar/interstellar Na D absorption line profiles of a sample of 23 Type Ia supernovae (SNe Ia), we determine that the properties of SN Ia progenitor systems and explosions are intimately connected. As demonstrated by Sternberg et al., half of all SNe Ia with detectable Na D absorption at the host-galaxy redshift in high-resolution spectroscopy have Na D line profiles with significant blueshifted absorption relative to the strongest absorption component, which indicates that a large fraction of SN Ia progenitor systems have strong outflows. In this study, we find that SNe Ia with blueshifted circumstellar/interstellar absorption systematically have higher ejecta velocities and redder colors at maximum brightness relative to the rest of the SN Ia population. This result is robust at a 98.9%-99.8% confidence level, providing the first link between the progenitor systems and properties of the explosion. This finding is further evidence that the outflow scenario is the correct interpretation of the blueshifted Na D absorption, adding additional confirmation that some SNe Ia are produced from a single-degenerate progenitor channel. An additional implication is that either SN Ia progenitor systems have highly asymmetric outflows that are also aligned with the SN explosion or SNe Ia come from a variety of progenitor systems where SNe Ia from systems with strong outflows tend to have more kinetic energy per unit mass than those from systems with weak or no outflows.

Foley, Ryan J.; Kirshner, Robert P. [Harvard-Smithsonian Center for Astrophysics, 60 Garden Street, Cambridge, MA 02138 (United States); Simon, Joshua D.; Burns, Christopher R. [Observatories of the Carnegie Institution for Science, 813 Santa Barbara Street, Pasadena, CA 91101 (United States); Gal-Yam, Avishay [Benoziyo Center for Astrophysics, Faculty of Physics, Weizmann Institute of Science, Rehovot 76100 (Israel); Hamuy, Mario [Departamento de Astronomia, Universidad de Chile, Casilla 36-D, Santiago (Chile); Morrell, Nidia I.; Phillips, Mark M. [Las Campanas Observatory, Carnegie Observatories, Casilla 601, La Serena (Chile); Shields, Gregory A. [Department of Astronomy, University of Texas, Austin, TX 78712 (United States); Sternberg, Assaf, E-mail: rfoley@cfa.harvard.edu [Max-Planck-Institut fuer Astrophysik, Karl-Schwarzschild-Strasse 1, 85741 Garching (Germany)

2012-06-20

275

Clonal analysis of hematopoietic progenitor cells in the zebrafish  

PubMed Central

Identification of hematopoietic progenitor cells in the zebrafish (Danio rerio) has been hindered by a lack of functional assays to gauge proliferative potential and differentiation capacity. To investigate the nature of myeloerythroid progenitor cells, we developed clonal methylcellulose assays by using recombinant zebrafish erythropoietin and granulocyte colony-stimulating factor. From adult whole kidney marrow, erythropoietin was required to support erythroid colony formation, and granulocyte colony-stimulating factor was required to support the formation of colonies containing neutrophils, monocytes, and macrophages. Myeloid and erythroid colonies showed distinct morphologies and were easily visualized and scored by their expression of lineage-specific fluorescent transgenes. Analysis of the gene-expression profiles after isolation of colonies marked by gata1:DsRed or mpx:eGFP transgenes confirmed our morphological erythroid and myeloid lineage designations, respectively. The majority of progenitor activity was contained within the precursor light scatter fraction, and more immature precursors were present within the lymphoid fraction. Finally, we performed kinetic analyses of progenitor activity after sublethal irradiation and demonstrated that recovery to preirradiation levels occurred by 14 days after irradiation. Together, these experiments provide the first report of clonal hematopoietic progenitor assays in the zebrafish and establish the number, characteristics, and kinetics of myeloerythroid progenitors during both steady-state and stress hematopoiesis.

Stachura, David L.; Svoboda, Ondrej; Lau, Ryan P.; Balla, Keir M.; Zon, Leonard I.; Bartunek, Petr

2011-01-01

276

Muscle: a source of progenitor cells for bone fracture healing  

PubMed Central

Bone repair failure is a major complication of open fracture, leading to non-union of broken bone extremities and movement at the fracture site. This results in a serious disability for patients. The role played by the periosteum and bone marrow progenitors in bone repair is now well documented. In contrast, limited information is available on the role played by myogenic progenitor cells in bone repair. In a recent article published in BMC Musculoskeletal Disorders, Liu et al. compared the presence of myogenic progenitor (MyoD lineage cells) in closed and open fractures. They showed that myogenic progenitors are present in open, but not closed fractures, suggesting that muscle satellite cells may colonize the fracture site in the absence of intact periosteum. Interestingly, these progenitors sequentially expressed a chondrogenic and, thereafter, an osteoblastic phenotype, suggestive of a functional role in the repair process. This finding opens up new perspectives for the research of orthopedic surgical methods, which could maximize myogenic progenitor access and mobilization to augment bone repair. Please see related article: http://www.biomedcentral.com/1471-2474/12/288

2011-01-01

277

Distinct FAK Activities Determine Progenitor and Mammary Stem Cell Characteristics.  

PubMed

Mammary stem cells (MaSC) and progenitor cells are important for mammary gland development and maintenance and may give rise to mammary cancer stem cells (MaCSC). Yet, there remains limited understanding of how these cells contribute to tumorigenesis. Here, we show that conditional deletion of focal adhesion kinase (FAK) in embryonic mammary epithelial cells (MaEC) decreases luminal progenitors and basal MaSCs, reducing their colony-forming and regenerative potentials in a cell-autonomous manner. Loss of FAK kinase activity in MaECs specifically impaired luminal progenitor proliferation and alveologenesis, whereas a kinase-independent activity of FAK supported ductal invasion and basal MaSC activity. Deficiency in luminal progenitors suppressed tumorigenesis and MaCSC formation in a mouse model of breast cancer. In contrast with the general inhibitory effect of FAK attenuation, inhibitors of FAK kinase preferentially inhibited proliferation and tumorsphere formation of luminal progenitor-like, but not MaSC-like, human breast cancer cells. Our findings establish distinct kinase-dependent and -independent activities of FAK that differentially regulate luminal progenitors and basal MaSCs. We suggest that targeting these distinct functions may tailor therapeutic strategies to address breast cancer heterogeneity more effectively. Cancer Res; 73(17); 5591-602. ©2013 AACR. PMID:23832665

Luo, Ming; Zhao, Xiaofeng; Chen, Song; Liu, Suling; Wicha, Max S; Guan, Jun-Lin

2013-07-05

278

Muscle: a source of progenitor cells for bone fracture healing.  

PubMed

Bone repair failure is a major complication of open fracture, leading to non-union of broken bone extremities and movement at the fracture site. This results in a serious disability for patients. The role played by the periosteum and bone marrow progenitors in bone repair is now well documented. In contrast, limited information is available on the role played by myogenic progenitor cells in bone repair. In a recent article published in BMC Musculoskeletal Disorders, Liu et al. compared the presence of myogenic progenitor (MyoD lineage cells) in closed and open fractures. They showed that myogenic progenitors are present in open, but not closed fractures, suggesting that muscle satellite cells may colonize the fracture site in the absence of intact periosteum. Interestingly, these progenitors sequentially expressed a chondrogenic and, thereafter, an osteoblastic phenotype, suggestive of a functional role in the repair process. This finding opens up new perspectives for the research of orthopedic surgical methods, which could maximize myogenic progenitor access and mobilization to augment bone repair. Please see related article: http://www.biomedcentral.com/1471-2474/12/288. PMID:22192862

Henrotin, Yves

2011-12-22

279

Colony forming cell assays for human hematopoietic progenitor cells.  

PubMed

Hematopoietic stem cells (HSCs) present in small numbers in adult bone marrow (BM), peripheral blood (PB) and umbilical cord blood (CB) produce a heterogeneous pool of progenitors that can be detected in vitro using colony forming cell (CFC) assays. Hematopoietic progenitor cells proliferate and differentiate to produce colonies of maturing cells when cultured in a semisolid methylcellulose-based medium that is supplemented with suitable growth factors and other supplements. The colonies are then classified and enumerated in situ by light microscopy or an automated imaging instrument. CFC assays are important tools in basic hematology research but are also used by clinical cell processing laboratories to measure the progenitor cell content of BM, CB and mobilized PB (MPB) preparations used for cell transplantation. Standard CFC assays for human progenitor cells require a culture period of at least 14 days to enable optimal outgrowth and differentiation of the maximum number of CFCs in a cell preparation. In this chapter protocols are described for the detection and enumeration of myeloid multipotential progenitors and committed progenitors of the erythroid, monocyte, and granulocyte lineages in samples from human PB, MPB, BM, and CB. In addition protocols are described for a modified version of the CFC-assay that allows accurate enumeration of total CFC numbers in CB or MPB after a culture period of only 7 days, but without distinction of colony types. PMID:23179838

Wognum, Bert; Yuan, Ning; Lai, Becky; Miller, Cindy L

2013-01-01

280

MiR-223 deficiency increases eosinophil progenitor proliferation.  

PubMed

Recently, microRNAs have been shown to be involved in hematopoietic cell development, but their role in eosinophilopoiesis has not yet been described. In this article, we show that miR-223 is upregulated during eosinophil differentiation in an ex vivo bone marrow-derived eosinophil culture system. Targeted ablation of miR-223 leads to an increased proliferation of eosinophil progenitors. We found upregulation of a miR-223 target gene, IGF1R, in the eosinophil progenitor cultures derived from miR-223(-/-) mice compared with miR-223(+/+) littermate controls. The increased proliferation of miR-223(-/-) eosinophil progenitors was reversed by treatment with an IGF1R inhibitor (picropodophyllin). Whole-genome microarray analysis of differentially regulated genes between miR-223(+/+) and miR-223(-/-) eosinophil progenitor cultures identified a specific enrichment in genes that regulate hematologic cell development. Indeed, miR-223(-/-) eosinophil progenitors had a delay in differentiation. Our results demonstrate that microRNAs regulate the development of eosinophils by influencing eosinophil progenitor growth and differentiation and identify a contributory role for miR-223 in this process. PMID:23325891

Lu, Thomas X; Lim, Eun-Jin; Besse, John A; Itskovich, Svetlana; Plassard, Andrew J; Fulkerson, Patricia C; Aronow, Bruce J; Rothenberg, Marc E

2013-01-16

281

Linking Type Ia Supernova Progenitors and Their Resulting Explosions  

NASA Astrophysics Data System (ADS)

Comparing the ejecta velocities at maximum brightness and narrow circumstellar/interstellar Na D absorption line profiles of a sample of 23 Type Ia supernovae (SNe Ia), we determine that the properties of SN Ia progenitor systems and explosions are intimately connected. As demonstrated by Sternberg et al., half of all SNe Ia with detectable Na D absorption at the host-galaxy redshift in high-resolution spectroscopy have Na D line profiles with significant blueshifted absorption relative to the strongest absorption component, which indicates that a large fraction of SN Ia progenitor systems have strong outflows. In this study, we find that SNe Ia with blueshifted circumstellar/interstellar absorption systematically have higher ejecta velocities and redder colors at maximum brightness relative to the rest of the SN Ia population. This result is robust at a 98.9%-99.8% confidence level, providing the first link between the progenitor systems and properties of the explosion. This finding is further evidence that the outflow scenario is the correct interpretation of the blueshifted Na D absorption, adding additional confirmation that some SNe Ia are produced from a single-degenerate progenitor channel. An additional implication is that either SN Ia progenitor systems have highly asymmetric outflows that are also aligned with the SN explosion or SNe Ia come from a variety of progenitor systems where SNe Ia from systems with strong outflows tend to have more kinetic energy per unit mass than those from systems with weak or no outflows.

Foley, Ryan J.; Simon, Joshua D.; Burns, Christopher R.; Gal-Yam, Avishay; Hamuy, Mario; Kirshner, Robert P.; Morrell, Nidia I.; Phillips, Mark M.; Shields, Gregory A.; Sternberg, Assaf

2012-06-01

282

Immunotherapeutic aspects of allogeneic peripheral progenitor cells.  

PubMed

In a newly developed murine model of allogeneic peripheral progenitor transplantation (PBPCT) we investigated the immunotherapeutic potential of allogeneic peripheral stem cells. The following topics were addressed by our experiments: (1) comparison of the graft-versus-leukemia effect exerted by allogeneic PBPCT compared to allogeneic BMT; (2) the influence of T-lymphocytes on GVL activity; (3) the possibility to enhance the GVL activity of allogeneic PBPCT grafts by ex vivo cytokine incubation. Balb/c mice received cells of the syngeneic B-lymphatic leukemia A20 2 days prior to TBI (7.5 Gy) and the respective graft. The recipients received allogeneic bone marrow grafts or allogeneic peripheral progenitor cells obtained after mobilization of the donors (DBA/2) with either G-CSF in a dose of 250 microg/kg/day for 5 days. In some experiments T lymphocytes were removed by immunomagnetic depletion with CD3-coated beads. An additional group received T cell-depleted and IL-2/IL12-activated PBPCT grafts. The antileukemic activity of an allogeneic PBPCT graft was significantly greater than the antileukemic activity of an allogeneic BMT graft of the same size. Relapse rates were 80% in syngeneic PBPCT, 60% after allogeneic BMT and 34% after allogeneic PBPCT. This rise in antileukemic activity is not accompanied by a rise in GVHD mortality. Depletion of T lymphocytes by CD3-coated beads resulted in a nearly complete loss of the GVL activity with a relapse rate of 75%. Incubation of the T-depleted graft with IL-2 and IL-12 to enhance NK-based GVL activity has only limited success after MHC-matched transplantation with a relapse rate of 55%. Allogeneic PBPC exert a pronounced antileukemic effect. After MHC-matched PBPCT, this GVL effect resides mostly on the T cells of the graft. Ex vivo activation of T cell-depleted grafts by IL-2 and IL-12 is accompanied by an only limited reduction of relapse rate. PBPC are a valuable modality for primary transplantation in situations with high risk of relapse and for the treatment of relapse after BMT. PMID:9712483

Glass, B; Uharek, L; Hartung, G; Zeis, M; Steinmann, J; Dreger, P; Krönke, M; Schmitz, N

1998-06-01

283

Clues on Type Ia Supernovae Progenitors  

SciTech Connect

We show that in the framework of canonical stellar evolution it is hard, if not impossible, to determine the growth in mass of a CO White Dwarf, up to the Chandrasekhar limit by means of mass transfer from its companion in a binary system. This is the case either if matter is accreted from a normal companion with an H-rich envelope or if direct CO accretion occurs from a CO WD companion. At variance, we show that if the effects of rotation are taken into account in modeling the accretion process, a CO WD can increase its mass at the expenses of the degenerate CO companion up and beyond 1.4 M{center_dot} , so that an explosive event of the type Ia class is naturally produced. This theoretical finding revives the Double Degenerate scenario for type Ia SNe progenitors. In such a case the internal spread in the observational properties of type Ia SNe may be interpreted as a consequence of different total masses; hence differences between SNe Ia in nearby elliptical galaxies and the majority of those in spirals should be expected and the current use of type Ia SNe as cosmological distance indicators should be justified.

Piersanti, Luciano; Tornambe, Amedeo [INAF - Osservatorio Astronomico di Teramo, via M. Maggini, SNC, 64100, Teramo (Italy)

2005-10-21

284

CI Aql: a Type Ia supernova progenitor?  

NASA Astrophysics Data System (ADS)

If recurrent novae are progenitors of Type Ia supernovae, their white dwarfs must have masses close to the Chandrasekhar limit. The most reliable means of determining white dwarf masses in recurrent novae is dynamically, via radial-velocity and rotational-broadening measurements of the companion star. Such measurements require the system to be both eclipsing and to show absorption features from the secondary star. Prior to the work reported here, the only dynamical mass estimate of a recurrent nova was for U Sco, which has a white dwarf mass of 1.55 ± 0.24 M?. We present new time-resolved, intermediate-resolution spectroscopy of the eclipsing recurrent nova CI Aquilae (CI Aql) during quiescence. We find the mass of the white dwarf to be 1.00 ± 0.14 M? and the mass of the secondary star to be 2.32 ± 0.19 M?. We estimate the radius of the secondary to be 2.07 ± 0.06 R?, implying that it is a slightly evolved early A-type star. The high mass ratio of q = 2.35 ± 0.24 and the high secondary-star mass implies that the mass transfer occurs on a thermal time-scale. We suggest that CI Aql is rapidly evolving into a supersoft X-ray source, and ultimately may explode as a Type Ia supernova within 10 Myr.

Sahman, D. I.; Dhillon, V. S.; Marsh, T. R.; Moll, S.; Thoroughgood, T. D.; Watson, C. A.; Littlefair, S. P.

2013-08-01

285

Circulating hematopoietic progenitor cells in runners.  

PubMed

Because endurance exercise causes release of mediators and growth factors active on the bone marrow, we asked whether it might affect circulating hematopoietic progenitor cells (HPCs) in amateur runners [n = 16, age: 41.8 +/- 13.5 (SD) yr, training: 93.8 +/- 31.8 km/wk] compared with sedentary controls (n = 9, age: 39.4 +/- 10.2 yr). HPCs, plasma cortisol, interleukin (IL)-6, granulocyte colony-stimulating factor (G-CSF), and the growth factor fms-like tyrosine kinase-3 (flt3)-ligand were measured at rest and after a marathon (M; n = 8) or half-marathon (HM; n = 8). Circulating HPC counts (i.e., CD34(+) cells and their subpopulations) were three- to fourfold higher in runners than in controls at baseline. They were unaffected by HM or M acutely but decreased the morning postrace. Baseline cortisol, flt3-ligand, IL-6, and G-CSF levels were similar in runners and controls. IL-6 and G-CSF increased to higher levels after M compared with HM, whereas cortisol and flt3-ligand increased similarly postrace. Our data suggest that increased HPCs reflect an adaptation response to recurrent, exercise-associated release of neutrophils and stress and inflammatory mediators, indicating modulation of bone marrow activity by habitual running. PMID:12381755

Bonsignore, Maria R; Morici, Giuseppe; Santoro, Alessandra; Pagano, Maria; Cascio, Lucia; Bonanno, Anna; Abate, Pietro; Mirabella, Franco; Profita, Mirella; Insalaco, Giuseppe; Gioia, Maria; Vignola, A Maurizio; Majolino, Ignazio; Testa, Ugo; Hogg, James C

2002-11-01

286

Cardiogenic differentiation and transdifferentiation of progenitor cells.  

PubMed

In recent years, cell transplantation has drawn tremendous interest as a novel approach to preserving or even restoring contractile function to infarcted hearts. A typical human infarct involves the loss of approximately 1 billion cardiomyocytes, and, therefore, many investigators have sought to identify endogenous or exogenous stem cells with the capacity to differentiate into committed cardiomyocytes and repopulate lost myocardium. As a result of these efforts, dozens of stem cell types have been reported to have cardiac potential. These include pluripotent embryonic stem cells, as well various adult stem cells resident in compartments including bone marrow, peripheral tissues, and the heart itself. Some of these cardiogenic progenitors have been reported to contribute replacement muscle through endogenous reparative processes or via cell transplantation in preclinical cardiac injury models. However, considerable disagreement exists regarding the efficiency and even the reality of cardiac differentiation by many of these stem cell types, making these issues a continuing source of controversy in the field. In this review, we consider approaches to cell fate mapping and establishing the cardiac phenotype, as well as the present state of the evidence for the cardiogenic and regenerative potential of the major candidate stem cell types. PMID:18988903

Reinecke, Hans; Minami, Elina; Zhu, Wei-Zhong; Laflamme, Michael A

2008-11-01

287

Wheat products as acceptable substitutes for rice.  

PubMed

The objective of the study was to compare the acceptability to semi-trained US American and Asian palatability panelist, of four wheat products processed to be possible replacers of rice in human diets. Products evaluated using rice as the control standard of excellence were steamed whole wheat, couscous (steamed, extracted wheat flour semolina), rosamarina (rice shaped, extracted wheat flour pasta), and bulgar (steamed, pre-cooked partly debranned, cracked wheat). Using a ten point hedonic rating scale, both groups of panelists gave rosamarina closely followed by couscous, most favorable ratings although these ratings were somewhat lower than that of the positive control, steamed polished rice. Bulgar wheat was given the lowest evaluation and was, in general, found to be an unacceptable replacement for rice by both American and Asian judges because of its dark, 'greasy' color and distinctive flavor. In their personal dietaries, judges included rice from 0.25 to 18 times per week with the Asian judges consuming rice significantly more times per week than did the American judges (10.8 +/- 4.71 vs 1.75 +/- 1.65, p < 0.01). However, rice consumption patterns, nationality, race, or sex of the judges was not demonstrated to affect scoring of the wheat products as rice replacers. PMID:8332588

Yu, B H; Kies, C

1993-07-01

288

Combined effect of salinity and hypoxia in wheat ( Triticum aestivum L.) and wheat- Thinopyrum amphiploids  

Microsoft Academic Search

The effects of sodium chloride salinity and hypoxia were studied in eight wheat lines and three wheat-Thinopyrum amphiploids in vermiculite-gravel culture. The lines were treated with either 100 or 150 mol m?3 NaCl with and without hypoxia. Saline hypoxic conditions significantly reduced the vegetative growth, water use, grain and straw yields for all wheat varieties except the amphiploids, whereas NaCl

J. Akhtar; J. Gorham; R. H. Qureshi

1994-01-01

289

Genetic structure of Argentinean hexaploid wheat germplasm  

PubMed Central

The identification of genetically homogeneous groups of individuals is an ancient issue in population genetics and in the case of crops like wheat, it can be valuable information for breeding programs, genetic mapping and germplasm resources. In this work we determined the genetic structure of a set of 102 Argentinean bread wheat (Triticum aestivum L.) elite cultivars using 38 biochemical and molecular markers (functional, closely linked to genes and neutral ones) distributed throughout 18 wheat chromosomes. Genetic relationships among these lines were examined using model-based clustering methods. In the analysis three subpopulations were identified which correspond largely to the origin of the germplasm used by the main breeding programs in Argentina.

Vanzetti, Leonardo S.; Yerkovich, Nadia; Chialvo, Eugenia; Lombardo, Lucio; Vaschetto, Luis; Helguera, Marcelo

2013-01-01

290

Durum wheat and allelopathy: toward wheat breeding for natural weed management  

PubMed Central

Wheat-derived foodstuffs represent about one-fifth of the calories consumed by humans worldwide. Bread wheat (Triticum aestivum L.) is one of the most important crops throughout the world, and it has been extensively studied for its allelopathic potential. In contrast, for allelopathy in durum wheat (Triticum turgidum ssp. durum), our knowledge is partial and fragmentary. Through highlighting recent advances in using allelopathy as a crop-breeding tool, we provide an overview of allelopathy in Triticum spp., to stimulate further coordinated breeding-oriented studies, to favor allelopathy exploitation for the sustainable cultivation of wheat, and in particular, to achieve improved biological weed control.

Fragasso, Mariagiovanna; Iannucci, Anna; Papa, Roberto

2013-01-01

291

21 CFR 136.180 - Whole wheat bread, rolls, and buns.  

Code of Federal Regulations, 2010 CFR

... 2009-04-01 false Whole wheat bread, rolls, and buns. 136.180 Section...Bakery Products § 136.180 Whole wheat bread, rolls, and buns. (a) Each of the foods whole wheat bread, graham bread, entire wheat...

2009-04-01

292

21 CFR 136.180 - Whole wheat bread, rolls, and buns.  

Code of Federal Regulations, 2010 CFR

... 2010-04-01 false Whole wheat bread, rolls, and buns. 136.180 Section...Bakery Products § 136.180 Whole wheat bread, rolls, and buns. (a) Each of the foods whole wheat bread, graham bread, entire wheat...

2010-04-01

293

Interleukin-1 regulates proliferation and differentiation of oligodendrocyte progenitor cells.  

PubMed

Interleukin-1 (IL-1) is a pleiotropic cytokine expressed during normal CNS development and in inflammatory demyelinating diseases, but remarkably little is known about its effect on oligodendroglial cells. In this study we explored the role of IL-1beta in oligodendrocyte progenitors and differentiated oligodendrocytes. The effects of IL-1beta were compared to those of IL-1 receptor antagonist, the specific inhibitor of IL-1 activity, since progenitors and differentiated oligodendrocytes produce IL-1beta and express IL-1 receptors. Unlike other proinflammatory cytokines (TNFalpha and IFNgamma), IL-1beta was not toxic for oligodendrocyte lineage cells. However, this cytokine inhibited proliferation of oligodendrocyte progenitors in the presence of growth factors (PDGF plus bFGF). This was evidenced by a significant decrease in both cells incorporating bromodeoxyuridine (45%) and total cell numbers (57%) after 6 days of treatment. Interestingly, IL-1beta blocked proliferation at the late progenitor/prooligodendrocyte (O4+) stage but did not affect proliferation of early progenitors (A2B5+). Inhibition of proliferation paralleled with promotion of differentiation, as revealed by the increased percentage of R-mab+ cells (6.7-fold). Moreover, when oligodendrocyte progenitors were allowed to differentiate in the absence of growth factors, treatment with IL-1beta promoted maturation to the MBP+ stage (4.2-fold) and survival of differentiating oligodendrocytes (2.1-fold). Regarding intracellular signaling, IL-1beta activated the p38 mitogen-activated protein kinase (MAPK) but not the p42/p44 MAPK and, when combined with growth factors, intensified p38 activation but inhibited the growth-factor-induced p42/p44 activation. IL-1beta also induced a time-dependent inhibition of PFGF-Ralpha gene expression. These results support a role for IL-1beta in promoting mitotic arrest and differentiation of oligodendrocyte progenitors as well as maturation and survival of differentiating oligodendrocytes. PMID:12139924

Vela, José M; Molina-Holgado, Eduardo; Arévalo-Martín, Angel; Almazán, Guillermina; Guaza, Carmen

2002-07-01

294

Promising genetic resources for resistance to wheat streak mosaic virus and the wheat curl mite in wheat- Thinopyrum partial amphiploids and their derivatives  

Microsoft Academic Search

Wheat streak mosaic virus (WSMV), vectored by the wheat curl mite (WCM),Aceria tosichella Keifer, is one of the most destructive viral diseases of wheat found in many wheat producing areas of the world. Host resistance is the most effective method for controlling this disease and its vector. Symptomatological analysis and enzyme-linked immunosorbent assay (ELISA) were used to characterize WSMV-resistance in

Hongjie Li; Robert L. Conner; Qin Chen; Robert J. Graf; André Laroche; F. Ahmad; A. D. Kuzyk

2005-01-01

295

Molecular assembly of botulinum neurotoxin progenitor complexes  

PubMed Central

Botulinum neurotoxin (BoNT) is produced by Clostridium botulinum and associates with nontoxic neurotoxin-associated proteins to form high-molecular weight progenitor complexes (PCs). The PCs are required for the oral toxicity of BoNT in the context of food-borne botulism and are thought to protect BoNT from destruction in the gastrointestinal tract and aid in absorption from the gut lumen. The PC can differ in size and protein content depending on the C. botulinum strain. The oral toxicity of the BoNT PC increases as the size of the PC increases, but the molecular architecture of these large complexes and how they contribute to BoNT toxicity have not been elucidated. We have generated 2D images of PCs from strains producing BoNT serotypes A1, B, and E using negative stain electron microscopy and single-particle averaging. The BoNT/A1 and BoNT/B PCs were observed as ovoid-shaped bodies with three appendages, whereas the BoNT/E PC was observed as an ovoid body. Both the BoNT/A1 and BoNT/B PCs showed significant flexibility, and the BoNT/B PC was documented as a heterogeneous population of assembly/disassembly intermediates. We have also determined 3D structures for each serotype using the random conical tilt approach. Crystal structures of the individual proteins were placed into the BoNT/A1 and BoNT/B PC electron density maps to generate unique detailed models of the BoNT PCs. The structures highlight an effective platform that can be engineered for the development of mucosal vaccines and the intestinal absorption of oral biologics.

Benefield, Desiree A.; Dessain, Scott K.; Shine, Nancy; Ohi, Melanie D.; Lacy, D. Borden

2013-01-01

296

Endothelial progenitor cells and integrins: adhesive needs  

PubMed Central

In the last decade there have been multiple studies concerning the contribution of endothelial progenitor cells (EPCs) to new vessel formation in different physiological and pathological settings. The process by which EPCs contribute to new vessel formation in adults is termed postnatal vasculogenesis and occurs via four inter-related steps. They must respond to chemoattractant signals and mobilize from the bone marrow to the peripheral blood; home in on sites of new vessel formation; invade and migrate at the same sites; and differentiate into mature endothelial cells (ECs) and/or regulate pre-existing ECs via paracrine or juxtacrine signals. During these four steps, EPCs interact with different physiological compartments, namely bone marrow, peripheral blood, blood vessels and homing tissues. The success of each step depends on the ability of EPCs to interact, adapt and respond to multiple molecular cues. The present review summarizes the interactions between integrins expressed by EPCs and their ligands: extracellular matrix components and cell surface proteins present at sites of postnatal vasculogenesis. The data summarized here indicate that integrins represent a major molecular determinant of EPC function, with different integrin subunits regulating different steps of EPC biology. Specifically, integrin ?4?1 is a key regulator of EPC retention and/or mobilization from the bone marrow, while integrins ?5?1, ?6?1, ?v?3 and ?v?5 are major determinants of EPC homing, invasion, differentiation and paracrine factor production. ?2 integrins are the major regulators of EPC transendothelial migration. The relevance of integrins in EPC biology is also demonstrated by many studies that use extracellular matrix-based scaffolds as a clinical tool to improve the vasculogenic functions of EPCs. We propose that targeted and tissue-specific manipulation of EPC integrin-mediated interactions may be crucial to further improve the usage of this cell population as a relevant clinical agent.

2012-01-01

297

Endothelial progenitor cells and integrins: adhesive needs.  

PubMed

In the last decade there have been multiple studies concerning the contribution of endothelial progenitor cells (EPCs) to new vessel formation in different physiological and pathological settings. The process by which EPCs contribute to new vessel formation in adults is termed postnatal vasculogenesis and occurs via four inter-related steps. They must respond to chemoattractant signals and mobilize from the bone marrow to the peripheral blood; home in on sites of new vessel formation; invade and migrate at the same sites; and differentiate into mature endothelial cells (ECs) and/or regulate pre-existing ECs via paracrine or juxtacrine signals. During these four steps, EPCs interact with different physiological compartments, namely bone marrow, peripheral blood, blood vessels and homing tissues. The success of each step depends on the ability of EPCs to interact, adapt and respond to multiple molecular cues. The present review summarizes the interactions between integrins expressed by EPCs and their ligands: extracellular matrix components and cell surface proteins present at sites of postnatal vasculogenesis. The data summarized here indicate that integrins represent a major molecular determinant of EPC function, with different integrin subunits regulating different steps of EPC biology. Specifically, integrin ?4?1 is a key regulator of EPC retention and/or mobilization from the bone marrow, while integrins ?5?1, ?6?1, ?v?3 and ?v?5 are major determinants of EPC homing, invasion, differentiation and paracrine factor production. ?2 integrins are the major regulators of EPC transendothelial migration. The relevance of integrins in EPC biology is also demonstrated by many studies that use extracellular matrix-based scaffolds as a clinical tool to improve the vasculogenic functions of EPCs. We propose that targeted and tissue-specific manipulation of EPC integrin-mediated interactions may be crucial to further improve the usage of this cell population as a relevant clinical agent. PMID:22410175

Caiado, Francisco; Dias, Sérgio

2012-03-12

298

Development and molecular composition of the hepatic progenitor cell niche.  

PubMed

End-stage liver diseases represent major health problems that are currently treated by liver transplantation. However, given the world-wide shortage of donor livers novel strategies are needed for therapeutic treatment. Adult stem cells have the ability to self-renew and differentiate into the more specialized cell types of a given organ and are found in tissues throughout the body. These cells, whose progeny are termed progenitor cells in human liver and oval cells in rodents, have the potential to treat patients through the generation of hepatic parenchymal cells, even from the patient's own tissue. Little is known regarding the nature of the hepatic progenitor cells. Though they are suggested to reside in the most distal part of the biliary tree, the canal of Hering, the lack of unique surface markers for these cells has hindered their isolation and characterization. Upon activation, they proliferate and form ductular structures, termed "ductular reactions", which radiate into the hepatic parenchyma. The ductular reactions contain activated progenitor cells that not only acquire a phenotype resembling that observed in developing liver but also display markers of differentiation shared with the cholangiocytic or hepatocytic lineages, the two parenchymal hepatic cell types. Interactions between the putative progenitor cells, the surrounding support cells and the extracellular matrix scaffold, all constituting the progenitor cell niche, are likely to be important for regulating progenitor cell activity and differentiation. Therefore, identifying novel progenitor cell markers and deciphering their microenvironment could facilitate clinical use. The aims of the present PhD thesis were to expand knowledge of the hepatic progenitor cell niche and characterize it both during development and in disease. Several animal models of hepatic injury are known to induce activation of the progenitor cells. In order to identify possible progenitor cell markers and niche components, we examined several genes upregulated in a global gene expression array conducted on one of these models, in which progenitor cells are activated. The protein expression patterns were evaluated in our collections of human embryonic and fetal livers, human liver diseases, and rodent hepatic injury models. When analyzing standard histological liver sections underlying connections and tissue architecture are not immediately evident. We therefore developed models for digitally reconstructing not only protein expression in serially cut tissue sections, but also vessels of the portal area. Article I constituted our earliest attempts to create 3D reconstructions of biological material. Human embryonic stem cell cultures were previously thought to consist of homogenously undifferentiated cells. The protocols for 3D reconstructions developed in this study demonstrated micro heterogeneity in expression of differentiation markers and provided the basis for later reconstructions of hepatic tissues. In article II we examined the expression patterns of chosen proteins seen upregulated in the gene array as well as classical hepatocytic and cholangiocytic markers in human liver disease and during prenatal development. Previous studies had indicated direct connections between activated progenitor cells apparently isolated in the parenchyma and the intrahepatic biliary tree. Our developed protocols for 3D reconstructions visually demonstrated direct connections between these entities. Analysis of protein expression in prenatal liver revealed the formation of the intrahepatic tree to occur through a special form of asymmetric tubulogenesis, only recently described in mice. In order to describe the composition of the hepatic progenitor cell niche and the localization of cell surface proteins in article III, the expression patterns of certain genes upregulated in the gene array analysis were analyzed in different models of rodent liver regeneration. We observed that the extracellular matrix molecules collagen 1a1, laminin, nidogen-1 and agrin embraced the biliary cells

Vestentoft, Peter Siig

2013-05-01

299

SUPERNOVA 2008bk AND ITS RED SUPERGIANT PROGENITOR  

SciTech Connect

We have obtained limited photometric and spectroscopic data for supernova (SN) 2008bk in NGC 7793, primarily at {approx}> 150 days after explosion. We find that it is a Type II-Plateau (II-P) SN that most closely resembles the low-luminosity SN 1999br in NGC 4900. Given the overall similarity between the observed light curves and colors of SNe 2008bk and 1999br, we infer that the total visual extinction to SN 2008bk (A{sub V} = 0.065 mag) must be almost entirely due to the Galactic foreground, similar to what has been assumed for SN 1999br. We confirm the identification of the putative red supergiant (RSG) progenitor star of the SN in high-quality g'r'i' images we had obtained in 2007 at the Gemini-South 8 m telescope. Little ambiguity exists in this progenitor identification, qualifying it as the best example to date, next to the identification of the star Sk -69 Degree-Sign 202 as the progenitor of SN 1987A. From a combination of photometry of the Gemini images with that of archival, pre-SN, Very Large Telescope JHK{sub s} images, we derive an accurate observed spectral energy distribution (SED) for the progenitor. We find from nebular strong-intensity emission-line indices for several H II regions near the SN that the metallicity in the environment is likely subsolar (Z Almost-Equal-To 0.6 Z{sub Sun }). The observed SED of the star agrees quite well with synthetic SEDs obtained from model RSG atmospheres with effective temperature T{sub eff} = 3600 {+-} 50 K. We find, therefore, that the star had a bolometric luminosity with respect to the Sun of log (L{sub bol}/L{sub Sun} ) = 4.57 {+-} 0.06 and radius R{sub *} = 496 {+-} 34 R{sub Sun} at {approx}6 months prior to explosion. Comparing the progenitor's properties with theoretical massive-star evolutionary models, we conclude that the RSG progenitor had an initial mass in the range of 8-8.5 M{sub Sun }. This mass is consistent with, albeit at the low end of, the inferred range of initial masses for SN II-P progenitors. It is also consistent with the estimated upper limit on the initial mass of the progenitor of SN 1999br, and it agrees with the low initial masses found for the RSG progenitors of other low-luminosity SNe II-P.

Van Dyk, Schuyler D.; Elias-Rosa, Nancy [Spitzer Science Center/Caltech, Mailcode 220-6, Pasadena, CA 91125 (United States); Davidge, Tim J., E-mail: vandyk@ipac.caltech.edu, E-mail: tim.davidge@nrc.ca [Herzberg Institute of Astrophysics, National Research Council of Canada, Victoria, B.C., V9E 2E7 (Canada); and others

2012-01-15

300

Corn and Wheat Markets in South Africa.  

National Technical Information Service (NTIS)

Corn is the major crop in the agriculture of the Republic of South Africa, and wheat plays an important role in the country's diet. Using appropriate economic information and econometric models, the factors affecting production and consumption of these tw...

S. Shapouri

1983-01-01

301

21 CFR 137.195 - Crushed wheat.  

Code of Federal Regulations, 2013 CFR

...DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) FOOD FOR HUMAN CONSUMPTION CEREAL FLOURS AND RELATED PRODUCTS Requirements for Specific Standardized Cereal Flours and Related Products § 137.195 Crushed wheat. Crushed...

2013-04-01

302

Green Revolution for Wheat in Developing Countries.  

National Technical Information Service (NTIS)

The green revolution has greatly increased the wheat supply in the developing world. The experience of Mexico, India, Pakistan, Turkey, and Argentina are reviewed here. Governments of these countries, except Argentina, used procurement programs and input ...

G. Vocke

1986-01-01

303

Testing the Quality of Wheat Products  

NSDL National Science Digital Library

This interactive activity adapted from Montana State University shows how various wheat products used in the food industry are tested to make sure they have the desired physical and nutritional characteristics.

Foundation, Wgbh E.

2010-06-30

304

Strategies to reverse endothelial progenitor cell dysfunction in diabetes.  

PubMed

Bone-marrow-derived cells-mediated postnatal vasculogenesis has been reported as the main responsible for the regulation of vascular homeostasis in adults. Since their discovery, endothelial progenitor cells have been depicted as mediators of postnatal vasculogenesis for their peculiar phenotype (partially staminal and partially endothelial), their ability to differentiate in endothelial cell line and to be incorporated into the vessels wall during ischemia/damage. Diabetes mellitus, a condition characterized by cardiovascular disease, nephropathy, and micro- and macroangiopathy, showed a dysfunction of endothelial progenitor cells. Herein, we review the mechanisms involved in diabetes-related dysfunction of endothelial progenitor cells, highlighting how hyperglycemia affects the different steps of endothelial progenitor cells lifetime (i.e., bone marrow mobilization, trafficking into the bloodstream, differentiation in endothelial cells, and homing in damaged tissues/organs). Finally, we review preclinical and clinical strategies that aim to revert diabetes-induced dysfunction of endothelial progenitor cells as a means of finding new strategies to prevent diabetic complications. PMID:22474422

Petrelli, Alessandra; Di Fenza, Raffaele; Carvello, Michele; Gatti, Francesca; Secchi, Antonio; Fiorina, Paolo

2012-02-22

305

X-ray signatures of type Ia supernova progenitors  

NASA Astrophysics Data System (ADS)

The nature of type Ia supernova progenitors remains unclear, despite more than 30 years of research. Two progenitor scenarios are normally considered: that of a massive white dwarf accreting material from a non-degenerate companion (the single-degenerate scenario), and that of a merging double white dwarf binary (the double-degenerate scenario). The X-ray signatures of the two scenarios are expected to be quite different, and we expect to detect 'naked', nearby, single-degenerate progenitors as supersoft X-ray sources (van den Heuvel et al. 1992). However, so far, a systematic search of the Chandra archive has yielded 10 non-detections (Nielsen et al. 2012) and one possible, somewhat ambiguous, detection (Roelofs et al. 2008). We discuss this search and the implications for determining the nature of type Ia supernova progenitors, as well as the possible importance of obscuration by local material lost from the progenitor systems into the circumbinary region (Nielsen et al. in prep.).

Nielsen, Mikkel

2012-09-01

306

Ginsenoside Rg1 promotes proliferation of hippocampal progenitor cells.  

PubMed

Neural progenitor cells (NPCs) exist not only in the developing brain, but also in certain areas in adult brain in mammals. Recent studies suggest that promoting neurogenesis in adult mammals might provide a therapeutic way to cure age-related neurodegenerative diseases. So, it will be of great value to find out drugs that can increase the proliferation and/or differentiation ability of neural progenitors. The present study investigated the influence of ginsenoside Rg1, an active ingredient of Panax ginseng C.A. Meyer, on proliferation ability of rodent hippocampal progenitor cells both in vitro and in vivo. Incubation of NPCs with ginsenoside Rg1 resulted in significant increase in absorbency value, 3H-thymidine incorporation and the number of proliferating progenitor cell spheres; In addition, 2 weeks Rg1 administration (i.p.) led to marked enhancement of the number of dividing cells in the hippocampus of adult mice. These findings suggest that ginsenoside Rg1 is involved in the regulation of proliferation of hippocampal progenitor cells and this effect may serve as one of the elementary mechanisms underlying its nootropic and anti-aging actions. PMID:15198871

Shen, Li-Hong; Zhang, Jun-Tian

2004-06-01

307

Myostatin promotes the terminal differentiation of embryonic muscle progenitors  

PubMed Central

Myostatin, a TGF-? family member, is an important regulator of adult muscle size. While extensively studied in vitro, the mechanisms by which this molecule mediates its effect in vivo are poorly understood. We addressed this question using chick and mouse embryos. We show that while myostatin overexpression in chick leads to an exhaustion of the muscle progenitor population that ultimately results in muscle hypotrophy, myostatin loss of function in chick and mouse provokes an expansion of this population. Our data demonstrate that myostatin acts in vivo to regulate the balance between proliferation and differentiation of embryonic muscle progenitors by promoting their terminal differentiation through the activation of p21 and MyoD. Previous studies have suggested that myostatin imposes quiescence on muscle progenitors. Our data suggest that myostatin’s effect on muscle progenitors is more complex than previously realized and is likely to be context-dependent. We propose a novel model for myostatin mode of action in vivo, in which myostatin affects the balance between proliferation and differentiation of embryonic muscle progenitors by enhancing their differentiation.

Manceau, Marie; Gros, Jerome; Savage, Kathleen; Thome, Virginie; McPherron, Alexandra; Paterson, Bruce; Marcelle, Christophe

2008-01-01

308

The Progenitor Mass of the Magnetar SGR1900+14  

NASA Astrophysics Data System (ADS)

Magnetars are young neutron stars with extreme magnetic fields (B gsim 1014-1015 G). How these fields relate to the properties of their progenitor stars is not yet clearly established. However, from the few objects associated with young clusters it has been possible to estimate the initial masses of the progenitors, with results indicating that a very massive progenitor star (M prog> 40 M _{?}) is required to produce a magnetar. Here, we present adaptive-optics assisted Keck/NIRC2 imaging and Keck/NIRSPEC spectroscopy of the cluster associated with the magnetar SGR 1900+14, and report that the initial progenitor star mass of the magnetar was a factor of 2 lower than this limit, M prog = 17 ± 2 M_{?}. Our result presents a strong challenge to the concept that magnetars can only result from very massive progenitors. Instead, we favor a mechanism which is dependent on more than just initial stellar mass for the production of these extreme magnetic fields, such as the "fossil-field" model or a process involving close binary evolution.

Davies, Ben; Figer, Don F.; Kudritzki, Rolf-Peter; Trombley, Christine; Kouveliotou, Chryssa; Wachter, Stefanie

2009-12-01

309

Angiotensin II stimulates proliferation of normal early erythroid progenitors.  

PubMed Central

Angiotensin II exerts a mitogenic effect in several in vitro models, but a direct effect on erythroid progenitors has not been documented. Angiotensin-converting enzyme inhibitors and losartan, an angiotensin II type 1 receptor (AT1) antagonist, ameliorate posttransplant erythrocytosis, without altering serum erythropoietin levels. We studied erythroid differentiation and the effect of angiotensin II on proliferation of erythroid progenitors by culturing CD34+ hematopoietic progenitor cells in liquid serum-free medium favoring growth of erythroid precursors. Aliquots of cells were collected every third day, and were used for RNA preparation. AT1 mRNA was detected after 6 d. In these same samples, erythroid-specific mRNA (erythropoietin receptor) was also detected. AT1 protein was detected in 7-d-old burst-forming units-erythroid colonies by Western blotting. The CD34+ cell liquid cultures were used to incubate erythroid precursors with angiotensin II from days 6-9. After incubation, cells were transferred to semisolid medium and cultured with erythropoietin. Angiotensin II increased proliferation of early erythroid progenitors, defined as increased numbers of burst-forming units-erythroid colonies. Losartan completely abolished this stimulatory effect of angiotensin II. Moreover, we observed increased numbers of erythroid progenitors in the peripheral blood of posttransplant erythrocytosis patients. Thus, activation of AT1 with angiotensin II enhances erythropoietin-stimulated erythroid proliferation in vitro. A putative defect in the angiotensin II/AT1 pathway may contribute to the pathogenesis of posttransplant erythrocytosis.

Mrug, M; Stopka, T; Julian, B A; Prchal, J F; Prchal, J T

1997-01-01

310

Vascular progenitor cells in chronic obstructive pulmonary disease.  

PubMed

Chronic obstructive pulmonary disease (COPD) is commonly associated with vascular changes in the pulmonary and systemic circulations. Pulmonary muscular arteries characteristically show intimal hyperplasia, which is produced in part by the proliferation of poorly differentiated smooth muscle cells. The origin of these cells has not been determined. Bone marrow has the capacity to produce and mobilize progenitor cells that may be recruited at sites of vascular damage and contribute to vascular repair through their differentiation into endothelial cells. Nevertheless, under some circumstances bone marrow-derived progenitor cells may migrate into the intima and differentiate into smooth muscle cells. Local factors and cell-to-cell contact are critical in determining the fate of progenitor cells in the vessel wall. Studies assessing the number of circulating bone marrow-derived vascular progenitor cells indicate that COPD is characterized by a reduction in circulating hemopoietic and vascular progenitors. The mechanisms of this reduction have not been elucidated. It has been suggested that this process may lead to reduced vascular repair capacity and increase the risk of cardiovascular complications, which are associated with significant morbidity and mortality in COPD. Further investigation in this field and elucidation of the underlying mechanisms will contribute to a better management of this major complication of COPD. PMID:22052932

Barberŕ, Joan Albert; Peinado, Víctor I

2011-11-01

311

Inhibition of cyclooxygenase (COX)-2 affects endothelial progenitor cell proliferation  

SciTech Connect

Growing evidence indicates that inducible cyclooxygenase-2 (COX-2) is involved in the pathogenesis of inflammatory disorders and various types of cancer. Endothelial progenitor cells recruited from the bone marrow have been shown to be involved in the formation of new vessels in malignancies and discussed for being a key point in tumour progression and metastasis. However, until now, nothing is known about an interaction between COX and endothelial progenitor cells (EPC). Expression of COX-1 and COX-2 was detected by semiquantitative RT-PCR and Western blot. Proliferation kinetics, cell cycle distribution and rate of apoptosis were analysed by MTT test and FACS analysis. Further analyses revealed an implication of Akt phosphorylation and caspase-3 activation. Both COX-1 and COX-2 expression can be found in bone-marrow-derived endothelial progenitor cells in vitro. COX-2 inhibition leads to a significant reduction in proliferation of endothelial progenitor cells by an increase in apoptosis and cell cycle arrest. COX-2 inhibition leads further to an increased cleavage of caspase-3 protein and inversely to inhibition of Akt activation. Highly proliferating endothelial progenitor cells can be targeted by selective COX-2 inhibition in vitro. These results indicate that upcoming therapy strategies in cancer patients targeting COX-2 may be effective in inhibiting tumour vasculogenesis as well as angiogenic processes.

Colleselli, Daniela [Pneumology Service-Division of General Internal Medicine, Department of Internal Medicine, Innsbruck Medical University, Anichstrasse 35, A-6020 Innsbruck (Austria); Bijuklic, Klaudija [Inflammation Research, Laboratory Division of General Internal Medicine, Department of Internal Medicine, Medical University of Innsbruck (Austria); Mosheimer, Birgit A. [Inflammation Research, Laboratory Division of General Internal Medicine, Department of Internal Medicine, Medical University of Innsbruck (Austria); Kaehler, Christian M. [Pneumology Service-Division of General Internal Medicine, Department of Internal Medicine, Innsbruck Medical University, Anichstrasse 35, A-6020 Innsbruck (Austria)]. E-mail: C.M.Kaehler@uibk.ac.at

2006-09-10

312

THE PROGENITOR MASS OF THE MAGNETAR SGR1900+14  

SciTech Connect

Magnetars are young neutron stars with extreme magnetic fields (B approx> 10{sup 14}-10{sup 15} G). How these fields relate to the properties of their progenitor stars is not yet clearly established. However, from the few objects associated with young clusters it has been possible to estimate the initial masses of the progenitors, with results indicating that a very massive progenitor star (M {sub prog}> 40 M odot) is required to produce a magnetar. Here, we present adaptive-optics assisted Keck/NIRC2 imaging and Keck/NIRSPEC spectroscopy of the cluster associated with the magnetar SGR 1900+14, and report that the initial progenitor star mass of the magnetar was a factor of 2 lower than this limit, M {sub prog} = 17 +- 2 M odot. Our result presents a strong challenge to the concept that magnetars can only result from very massive progenitors. Instead, we favor a mechanism which is dependent on more than just initial stellar mass for the production of these extreme magnetic fields, such as the 'fossil-field' model or a process involving close binary evolution.

Davies, Ben [School of Physics and Astronomy, University of Leeds, Woodhouse Lane, Leeds LS2 9JT (United Kingdom); Figer, Don F.; Trombley, Christine [Chester F. Carlson Center for Imaging Science, Rochester Institute of Technology, 54 Lomb Memorial Drive, Rochester, NY 14623 (United States); Kudritzki, Rolf-Peter [Institute for Astronomy, University of Hawaii, 2680 Woodlawn Drive, Honolulu, HI 96822 (United States); Kouveliotou, Chryssa [Space Science Office, VP62, NASA/Marshall Space Flight Center, Huntsville, AL 35812 (United States); Wachter, Stefanie [Spitzer Science Center, 1200 E. California Blvd., California Institute of Technology, Pasadena, CA 91125 (United States)

2009-12-10

313

[Microglia arise from extra-embryonic yolk sac primitive progenitors].  

PubMed

Microglia are the resident macrophage population of the central nervous system (CNS). Adequate microglia function is crucial for the homeostasis of the CNS in health and disease, as they represent the first line of defence against pathogens, contributing to immune responses, but are also involved in tissue repair and remodeling. It is therefore crucial to better understand microglia origin and homeostasis. Much controversy remains regarding the nature of microglial progenitors, as the exact contribution and persistence of embryonic and post-natal hematopoietic progenitors to the adult microglial pool in the steady state remained unclear. In this study, we show that post-natal hematopoietic progenitors do not significantly contribute to microglia homeostasis in the adult brain in mice. In vivo lineage tracing studies established that adult microglia derives from primitive hematopoietic progenitors that arise before embryonic day 8. These results identify microglia as an ontogenically distinct population in the mononuclear phagocyte system and have implications for the use of embryonically-derived microglial progenitors for the treatment of various brain disorders. PMID:21880259

Ginhoux, Florent; Merad, Miriam

2011-08-31

314

Bioethanol production from ammonia percolated wheat straw  

Microsoft Academic Search

This study examined the effectiveness of ammonia percolation pretreatment of wheat straw for ethanol production. Ground wheat\\u000a straw at a 10% (w\\/v) loading was pretreated with a 15% (v\\/v) ammonia solution. The experiments were performed at treatment\\u000a temperature of 50?170°C and residence time of 10?150 min. The solids treated with the ammonia solution showed high lignin\\u000a degradation and sugar availability.

Minhee Han; Se-Kwon Moon; Yule Kim; Youngran Kim; Bongwoo Chung; Gi-Wook Choi

2009-01-01

315

Wheat gluten as a protein ingredient  

Microsoft Academic Search

Wheat gluten is a unique cereal protein due to its property of high elasticity. This elasticity is only present in hydrated\\u000a gluten, and it is destroyed by heating. The property permits the formation of gas cells in flour dough, and is the essential\\u000a cause of the texture of our daily bread. Wheat gluten is produced industrially from flour rather than

Norman Wookey

1979-01-01

316

Challenges to wheat production in South Asia  

Microsoft Academic Search

Wheat is the second major staple crop, after rice, in India and Pakistan and is also gaining similar importance in Nepal and\\u000a Bangladesh. Wheat production in South Asia has increased from 15 mt in 1960s to 95.5 mt during 2004–2005. It still needs to\\u000a grow at the rate of 2–2.5% annually until the middle of 21st century. However, for India, recent estimations

R. Chatrath; B. Mishra; G. Ortiz Ferrara; S. K. Singh; A. K. Joshi

2007-01-01

317

Genetic Determination of Breadmaking Quality in Wheat  

Microsoft Academic Search

Allelic variability of different protein and molecular markers and evaluation of their potential for bread-making quality prediction in 150 hexaploid wheat genotypes were discused. Seventeen Glu-1 alleles were scored, 3 at the Glu-A1, 11 at the Glu-B1, and 3 at the Glu-D1. Typical HMW glutenin composition was 2* 7+9 5+10. Wheat-rye translocation 1BL\\/1RS was present in 20,7% genotypes. According to

Dragana OBREHT; Borislav KOBILJSKI; Milutin BEDE

318

Drought Tolerance in Modern and Wild Wheat  

PubMed Central

The genus Triticum includes bread (Triticum aestivum) and durum wheat (Triticum durum) and constitutes a major source for human food consumption. Drought is currently the leading threat on world's food supply, limiting crop yield, and is complicated since drought tolerance is a quantitative trait with a complex phenotype affected by the plant's developmental stage. Drought tolerance is crucial to stabilize and increase food production since domestication has limited the genetic diversity of crops including wild wheat, leading to cultivated species, adapted to artificial environments, and lost tolerance to drought stress. Improvement for drought tolerance can be achieved by the introduction of drought-grelated genes and QTLs to modern wheat cultivars. Therefore, identification of candidate molecules or loci involved in drought tolerance is necessary, which is undertaken by “omics” studies and QTL mapping. In this sense, wild counterparts of modern varieties, specifically wild emmer wheat (T. dicoccoides), which are highly tolerant to drought, hold a great potential. Prior to their introgression to modern wheat cultivars, drought related candidate genes are first characterized at the molecular level, and their function is confirmed via transgenic studies. After integration of the tolerance loci, specific environment targeted field trials are performed coupled with extensive analysis of morphological and physiological characteristics of developed cultivars, to assess their performance under drought conditions and their possible contributions to yield in certain regions. This paper focuses on recent advances on drought related gene/QTL identification, studies on drought related molecular pathways, and current efforts on improvement of wheat cultivars for drought tolerance.

Budak, Hikmet; Kantar, Melda; Yucebilgili Kurtoglu, Kuaybe

2013-01-01

319

Wheat production in controlled environments  

NASA Astrophysics Data System (ADS)

Our goal is to optimize conditions for maximum yield and quality of wheat to be used in a controlled-environment, life-support system (CELSS) in a Lunar or Martian base or perhaps in a space craft. With yields of 23 to 57 g m-2 d-1 of edible biomass, a minimum size for a CELSS would be between 12 and 30 m2 per person, utilizing about 600 W m-2 of electrical energy for artificial light. Temperature, irradiance, photoperiod, carbon-dioxide levels, humidity, and wind velocity are controlled in state-of-the-art growth chambers. Nutrient solutions (adjusted for wheat) are supplied to the roots via a recirculating system that controls pH by adding HNO3 and controlling the NO3/NH4 ratio in solution. A rock-wool plant support allows direct seeding and densities up to 10,000 plants per meter2. Densities up to 2000 plants m-2 appear to increase seed yield. Biomass production increases almost linearily with increasing irradiance from 400 to 1700 ?mol m-2 s-1 of photosynthetic photon flux (PPF), but the efficiency of light utilization decreases over this range. Photoperiod and temperature both have a profound influence on floral initiation, spikelet formation, stem elongation, and fertilization. High temperatures (25 to 27°C) and long days shorten the life cycle and promote rapid growth, but cooler temperatures (20°C) and shorter days greatly increase seed number per head and thus yield (g m-2). The life cycle is lengthened in these conditions but yield per day (g m-2 d-1) is still increased. We have evaluated about 600 cultivars from around the world and have developed several breeding lines for our controlled conditions. Some of our ultra-dwarf lines (30 to 50 cm tall) look especially promising with high yields and high harvest indices (percent edible biomass).

Salisbury, Frank B.; Bugbee, Bruce; Bubenheim, David

320

Omega 3 fatty acids reduce myeloid progenitor cell frequency in the bone marrow of mice and promote progenitor cell differentiation  

PubMed Central

Background Omega 3 fatty acids have been found to inhibit proliferation, induce apoptosis, and promote differentiation in various cell types. The processes of cell survival, expansion, and differentiation are of key importance in the regulation of hematopoiesis. We investigated the role of omega 3 fatty acids in controlling the frequency of various myeloid progenitor cells in the bone marrow of mice. Increased progenitor cell frequency and blocked differentiation are characteristics of hematopoietic disorders of the myeloid lineage, such as myeloproliferative diseases and myeloid leukemias. Results We found that increasing the proportion of omega 3 fatty acids relative to the proportion of omega 6 fatty acids in the diet caused increased differentiation and reduced the frequency of myeloid progenitor cells in the bone marrow of mice. Furthermore, this had no adverse effect on peripheral white blood cell counts. Conclusion Our results indicate that omega 3 fatty acids impact hematopoietic differentiation by reducing myeloid progenitor cell frequency in the bone marrow and promoting progenitor cell differentiation. Further exploration of this discovery could lead to the use of omega 3 fatty acids as a therapeutic option for patients that have various disorders of hematopoiesis.

Varney, Melinda E; Hardman, W Elaine; Sollars, Vincent E

2009-01-01

321

CXCR4 expression in prostate cancer progenitor cells.  

PubMed

Tumor progenitor cells represent a population of drug-resistant cells that can survive conventional chemotherapy and lead to tumor relapse. However, little is known of the role of tumor progenitors in prostate cancer metastasis. The studies reported herein show that the CXCR4/CXCL12 axis, a key regulator of tumor dissemination, plays a role in the maintenance of prostate cancer stem-like cells. The CXCL4/CXCR12 pathway is activated in the CD44(+)/CD133(+) prostate progenitor population and affects differentiation potential, cell adhesion, clonal growth and tumorigenicity. Furthermore, prostate tumor xenograft studies in mice showed that a combination of the CXCR4 receptor antagonist AMD3100, which targets prostate cancer stem-like cells, and the conventional chemotherapeutic drug Taxotere, which targets the bulk tumor, is significantly more effective in eradicating tumors as compared to monotherapy. PMID:22359577

Dubrovska, Anna; Elliott, Jimmy; Salamone, Richard J; Telegeev, Gennady D; Stakhovsky, Alexander E; Schepotin, Ihor B; Yan, Feng; Wang, Yan; Bouchez, Laure C; Kularatne, Sumith A; Watson, James; Trussell, Christopher; Reddy, Venkateshwar A; Cho, Charles Y; Schultz, Peter G

2012-02-16

322

World Food Grain Trade, 1962-83: Wheat, Rice, and Wheat Flour.  

National Technical Information Service (NTIS)

World trade in food grains (wheat, rice, and wheat flour) more than doubled from 1962 to 1983, while the number of countries participating in world trade increased 85 percent. Food grain consumption has increased faster than production in most countries s...

A. B. Mackie S. W. Hiemstra S. L. Rosen

1985-01-01

323

Solid-Stemmed Wheat Does Not Affect Overwintering Mortality of the Wheat Stem Sawfly, Cephus cinctus  

PubMed Central

The wheat stem sawfly, Cephus cinctus Norton (Hymenoptera: Cephidae), is a key pest of wheat in the northern Great Plains of North America. Host plant resistance in the form of solid-stemmed wheat cultivars is the main control strategy for C. cinctus. This study investigated the effect of novel and traditional solid wheat hosts on the overwintering mortality and cold-hardiness of C. cinctus. Field conditions from 2003–2005 showed that overwintering mortality in various wheat cultivars averaged 8% and was not related to the type of wheat cultivar. Similarly, supercooling points (-22° C) were not influenced by wheat host type. C. cintus are cold-hardy; up to 80% survive 10 days at -20° C and 10% survive 40 days. Its overwintering microhabitat near the crown area of the plant is well insulated for temperatures above -10° C and remains ? 20° C above ambient minima. These data suggest that winter mortality is a minor factor in the population dynamics of wheat stem sawfly, and despite clear detrimental effects on larval weight and adult fitness, solid-stemmed cultivars do not reduce the ability of larvae to survive winters.

Carcamo, Hector A.; Beres, Brian L.; Herle, Carolyn E.; McLean, Hugh; McGinne, Sean

2011-01-01

324

Pathogenicity of three isolates of Rhizoctonia sp. from wheat and peanut on hard red winter wheat  

Technology Transfer Automated Retrieval System (TEKTRAN)

Rhizoctonia-induced root diseases can significantly affect wheat and peanut production where these two field crops are grown in rotation. Hence, this study characterized two isolates of Rhizoctonia spp. from wheat [R. cerealis (RC) and R. solani (RSW)] and one from peanut [R. solani (RSP) ] for cul...

325

Solid-stemmed wheat does not affect overwintering mortality of the wheat stem sawfly, Cephus cinctus.  

PubMed

The wheat stem sawfly, Cephus cinctus Norton (Hymenoptera: Cephidae), is a key pest of wheat in the northern Great Plains of North America. Host plant resistance in the form of solid-stemmed wheat cultivars is the main control strategy for C. cinctus. This study investigated the effect of novel and traditional solid wheat hosts on the overwintering mortality and cold-hardiness of C. cinctus. Field conditions from 2003-2005 showed that overwintering mortality in various wheat cultivars averaged 8% and was not related to the type of wheat cultivar. Similarly, supercooling points (-22° C) were not influenced by wheat host type. C. cintus are cold-hardy; up to 80% survive 10 days at -20° C and 10% survive 40 days. Its overwintering microhabitat near the crown area of the plant is well insulated for temperatures above -10° C and remains ~ 20° C above ambient minima. These data suggest that winter mortality is a minor factor in the population dynamics of wheat stem sawfly, and despite clear detrimental effects on larval weight and adult fitness, solid-stemmed cultivars do not reduce the ability of larvae to survive winters. PMID:22235942

Cárcamo, Héctor A; Beres, Brian L; Herle, Carolyn E; McLean, Hugh; McGinne, Sean

2011-01-01

326

Aging is not associated with bone marrow-resident progenitor cell depletion.  

PubMed

Changes in progenitor cell biology remain at the forefront of many theories of biologic aging, but there are limited studies evaluating this in humans. Aging has been associated with a progressive depletion of circulating progenitor cells, but age-related bone marrow-resident progenitor cell depletion has not been systematically determined in humans. Patients undergoing total hip replacement were consented, and bone marrow and peripheral progenitor cells were enumerated based on aldehyde dehydrogenase activity and CD34 and CD133 expression. Circulating progenitors demonstrated an age-dependent decline. In contrast, marrow-resident progenitor cell content demonstrated no age association with any progenitor cell subtype. In humans, aging is associated with depletion of circulating, but not marrow-resident, progenitors. This finding has impact on the mechanism(s) responsible for age-related changes in circulating stem cells and important implications for the use of autologous marrow for the treatment of age-related diseases. PMID:20591876

Povsic, Thomas J; Zhou, Jiying; Adams, Stacie D; Bolognesi, Michael P; Attarian, David E; Peterson, Eric D

2010-06-30

327

Tcf7l1 is required for spinal cord progenitor maintenance  

PubMed Central

Neural progenitor cells must be maintained during development in order to produce the full complement of neuronal and glial derivatives. While molecular pathways have been identified that inhibit progenitor differentiation, it is unclear whether the progenitor state itself is actively maintained. In this study we have investigated the role of Tcf7l1 (formerly named Tcf3) in maintaining spinal progenitor characteristics and allowing the continued production of neurons and glia following primary neurogenesis. We find that spinal cord progenitor markers are progressively lost in embryos lacking Tcf7l1, and that the number of proliferative progenitors decreases accordingly. Furthermore, we show that the production of both neuronal and glial secondary derivatives of the pMN progenitor pool requires Tcf7l1. Together, these results indicate that Tcf7l1 plays an important role in spinal cord progenitor maintenance, indicating that this core function is conserved throughout multiple epithelial cell populations.

Kim, Hyung-Seok; Dorsky, Richard I.

2011-01-01

328

Hematopoietic stem cell and progenitor cell mechanisms in myelodysplastic syndromes  

PubMed Central

Myelodysplastic syndromes (MDS) are a group of disorders characterized by variable cytopenias and ineffective hematopoiesis. Hematopoietic stem cells (HSCs) and myeloid progenitors in MDS have not been extensively characterized. We transplanted purified human HSCs from MDS samples into immunodeficient mice and show that HSCs are the disease-initiating cells in MDS. We identify a recurrent loss of granulocyte-macrophage progenitors (GMPs) in the bone marrow of low risk MDS patients that can distinguish low risk MDS from clinical mimics, thus providing a simple diagnostic tool. The loss of GMPs is likely due to increased apoptosis and increased phagocytosis, the latter due to the up-regulation of cell surface calreticulin, a prophagocytic marker. Blocking calreticulin on low risk MDS myeloid progenitors rescues them from phagocytosis in vitro. However, in the high-risk refractory anemia with excess blasts (RAEB) stages of MDS, the GMP population is increased in frequency compared with normal, and myeloid progenitors evade phagocytosis due to up-regulation of CD47, an antiphagocytic marker. Blocking CD47 leads to the selective phagocytosis of this population. We propose that MDS HSCs compete with normal HSCs in the patients by increasing their frequency at the expense of normal hematopoiesis, that the loss of MDS myeloid progenitors by programmed cell death and programmed cell removal are, in part, responsible for the cytopenias, and that up-regulation of the “don’t eat me” signal CD47 on MDS myeloid progenitors is an important transition step leading from low risk MDS to high risk MDS and, possibly, to acute myeloid leukemia.

Pang, Wendy W.; Pluvinage, John V.; Price, Elizabeth A.; Sridhar, Kunju; Arber, Daniel A.; Greenberg, Peter L.; Schrier, Stanley L.; Park, Christopher Y.; Weissman, Irving L.

2013-01-01

329

Rates and progenitors of type Ia supernovae  

SciTech Connect

The remarkable uniformity of Type Ia supernovae has allowed astronomers to use them as distance indicators to measure the properties and expansion history of the Universe. However, Type Ia supernovae exhibit intrinsic variation in both their spectra and observed brightness. The brightness variations have been approximately corrected by various methods, but there remain intrinsic variations that limit the statistical power of current and future observations of distant supernovae for cosmological purposes. There may be systematic effects in this residual variation that evolve with redshift and thus limit the cosmological power of SN Ia luminosity-distance experiments. To reduce these systematic uncertainties, we need a deeper understanding of the observed variations in Type Ia supernovae. Toward this end, the Nearby Supernova Factory has been designed to discover hundreds of Type Ia supernovae in a systematic and automated fashion and study them in detail. This project will observe these supernovae spectrophotometrically to provide the homogeneous high-quality data set necessary to improve the understanding and calibration of these vital cosmological yardsticks. From 1998 to 2003, in collaboration with the Near-Earth Asteroid Tracking group at the Jet Propulsion Laboratory, a systematic and automated searching program was conceived and executed using the computing facilities at Lawrence Berkeley National Laboratory and the National Energy Research Supercomputing Center. An automated search had never been attempted on this scale. A number of planned future large supernovae projects are predicated on the ability to find supernovae quickly, reliably, and efficiently in large datasets. A prototype run of the SNfactory search pipeline conducted from 2002 to 2003 discovered 83 SNe at a final rate of 12 SNe/month. A large, homogeneous search of this scale offers an excellent opportunity to measure the rate of Type Ia supernovae. This thesis presents a new method for analyzing the true sensitivity of a multi-epoch supernova search and finds a Type Ia supernova rate from z {approx} 0.01-0.1 of r{sub V} = 4.26{sub -1.93 -0.10}{sup +1.39 +0.10} h{sup 3} x 10{sup -4} SNe Ia/yr/Mpc{sup 3} from a preliminary analysis of a subsample of the SNfactory prototype search. Several unusual supernovae were found in the course of the SNfactory prototype search. One in particular, SN 2002ic, was the first SN Ia to exhibit convincing evidence for a circumstellar medium and offers valuable insight into the progenitors of Type Ia supernovae.

Wood-Vasey, William Michael

2004-08-16

330

The Progenitors of Dwarf Spheroidal Galaxies  

NASA Astrophysics Data System (ADS)

The gas-deficient dwarf spheroidal (dSph) galaxies present an evolutionary puzzle that we explore in 40 early-type and late-type dwarfs in the Local Group and nearby field. Although dSph's experienced star formation over extended time spans in their youths, today all but one are completely free of detectable interstellar material, even in the Fornax dSph, where stars formed in the last 100 Myr. Combining photometric and spectroscopic stellar metallicity estimates for red giant branches with high-sensitivity H I 21 cm line data from the literature, we show that the well-established offset in luminosity-metallicity relationships for dSph's and dwarf irregular (dIrr) galaxies exists also when confining the comparison to their old stellar populations: dSph's have higher mean stellar metallicities for a fixed optical luminosity. Evidently star formation in younger dSph's was more vigorous than in the youthful dIrr's, leading to more efficient enrichment. Dwarf galaxies, whose locus in the luminosity-metallicity diagram is consistent with that of dSph's, even when baryonic luminosities are considered, are the ``transition-type dwarfs'' Phoenix, DDO 210, LGS 3, Antlia, and KKR 25. These dwarfs have mixed dIrr/dSph morphologies, low stellar masses, low angular momentum, and H I contents of at most a few 106 Msolar. Unlike dIrr's many transition-type dwarfs would closely resemble dSph's if their gas were removed, as required to become a dSph; they are likely dSph progenitors. As gas removal is the key factor for such a transition, we consider the empirical evidence in favor and against various gas removal processes. We suggest that internal gas removal mechanisms are inadequate and favor ram-pressure stripping to clean the bulk of interstellar matter from galaxies to make dSph's. A combination of initial conditions and environment seems to support the formation of dSph's: nearby dSph's appear to form from small galaxies with active early star formation, whose evolution halts due to externally induced gas loss. Transition-type dwarfs, then, are dSph's that kept their interstellar medium and therefore should replace dSph's in isolated locations where stripping is ineffective.

Grebel, Eva K.; Gallagher, John S., III; Harbeck, Daniel

2003-04-01

331

ON IDENTIFYING THE PROGENITORS OF Type Ia SUPERNOVAE  

SciTech Connect

We propose two new means of identifying the main class of progenitors of Type Ia supernovae-single or double degenerate: (1) if the range of supernova properties is significantly determined by the range of viewing angles of non-spherically symmetric explosions, then the nature of the correlation between polarization and another property (for example, the velocity gradient) can be used to determine the geometry of the asymmetry and hence the nature of the progenitor, and (2) in the double- but not in the single-degenerate case, the range in the observed properties (e.g., velocity gradients) is likely to increase with the amount of carbon seen in the ejecta.

Livio, Mario; Pringle, J. E., E-mail: mlivio@stsci.edu [Space Telescope Science Institute, Baltimore, MD (United States)

2011-10-10

332

Selective uptake of boronophenylalanine by glioma stem/progenitor cells.  

PubMed

The success of boron neutron capture therapy (BNCT) depends on the amount of boron in cells and the tumor/blood and tumor/(normal tissue) boron concentration ratios. For the first time, measurements of boron uptake in both stem/progenitor and differentiated glioma cells were performed along with measurements of boron biodistribution in suitable animal models. In glioma stem/progenitor cells, the selective accumulation of boronophenylalanine (BPA) was lower, and retention of boron after BPA removal was longer than in differentiated glioma cells in vitro. However, boron biodistribution was not statistically significantly different in mice with xenografts. PMID:22728842

Sun, Ting; Zhou, Youxin; Xie, Xueshun; Chen, Guilin; Li, Bin; Wei, Yongxin; Chen, Jinming; Huang, Qiang; Du, Ziwei

2012-04-12

333

Endothelial progenitor cells: a new player in lupus?  

PubMed Central

Patients with systemic lupus erythematosus (SLE) have a greatly increased risk of cardiovascular disease. There is growing interest in the link between vascular damage and lupus-specific inflammatory factors. Impaired endothelial repair could account for the endothelial dysfunction in this patient group. This review describes the contribution that endothelial progenitor cells could play in the pathogenesis of premature vascular damage in this disease. The methods of isolation, detection, and characterization of endothelial progenitor cells, together with their potential role in repair of the endothelium and as a therapeutic target in SLE, are discussed.

2012-01-01

334

Activin A expression regulates multipotency of mesenchymal progenitor cells  

Microsoft Academic Search

Introduction  Bone marrow (BM) stroma currently represents the most common and investigated source of mesenchymal progenitor cells (MPCs);\\u000a however, comparable adult progenitor or stem cells have also been isolated from a wide variety of tissues. This study aims\\u000a to assess the functional similarities of MPCs from different tissues and to identify specific factor(s) related to their multipotency.\\u000a \\u000a \\u000a \\u000a \\u000a Methods  For this purpose, we

Farida Djouad; Wesley M Jackson; Brent E Bobick; Sasa Janjanin; Yingjie Song; George TJ Huang; Rocky S Tuan

2010-01-01

335

WNT\\/?-Catenin Mediates Radiation Resistance of Mouse Mammary Progenitor Cells  

Microsoft Academic Search

Recent studies have identified a subpopulation of highly tumorigenic cells with stem\\/progenitor cell properties from human breast cancers, and it has been suggested that stem\\/progenitor cells, which remain after breast cancer therapy, may give rise to recurrent disease. We hypothesized that progenitor cells are resistant to radiation, a component of conventional breast cancer therapy, and that that resistance is mediated

Wendy A. Woodward; Mercy S. Chen; Fariba Behbod; Maria P. Alfaro; Thomas A. Buchholz; Jeffrey M. Rosen

2007-01-01

336

Hard X-Ray Emission from Progenitors of Type Ia Supernovae  

Microsoft Academic Search

Recurrent nova (RN) contain white dwarfs (WDs) whose masses are close to the Chandrasekhar limit. Some RN may thus be progenitors of type Ia supernovae (SNIa). To develop a tool for finding SNIa progenitor candidates at an earlier stage along the path to the Chandrasekhar limit, and to constrain the properties of known candidate SNIa progenitors, we propose to test

Jennifer Sokoloski

2009-01-01

337

Regeneration of Hippocampal Pyramidal Neurons after Ischemic Brain Injury by Recruitment of Endogenous Neural Progenitors  

Microsoft Academic Search

The adult brain is extremely vulnerable to various insults. The recent discovery of neural progenitors in adult mammals, however, raises the possibility of repairing damaged tissue by recruiting their latent regenerative potential. Here we show that activation of endogenous progenitors leads to massive regeneration of hippocampal pyramidal neurons after ischemic brain injury. Endogenous progenitors proliferate in response to ischemia and

Hirofumi Nakatomi; Toshihiko Kuriu; Shigeo Okabe; Shin-ichi Yamamoto; Osamu Hatano; Nobutaka Kawahara; Akira Tamura; Takaaki Kirino; Masato Nakafuku

2002-01-01

338

Compositions comprising vascular and myocyte progenitor cells and methods of their use  

US Patent & Trademark Office Database

The invention provides compositions of adult cardiac vascular progenitor cells (VPCs) and adult cardiac myocyte progenitor cells (MPCs) useful for the treatment of various cardiac conditions. The invention also encompasses methods of generating a biological bypass, repairing damaged myocardium, and treating or preventing hypertensive cardiomyopathy and heart failure with the compositions of the invention. Methods of isolating the cardiac progenitor cells are also disclosed.

2012-02-21

339

Economics of Small-Scale Wheat Production Technologies for Kenya.  

National Technical Information Service (NTIS)

The objectives of the study are: To analyze the profitability to farmers of smallholder wheat production technologies, specifically for the Nakuri district of Kenya; to analyze the comparative advantage of smallholder wheat technologies in the Nakuri dist...

J. Longmire J. Lugogo

1989-01-01

340

21 CFR 139.180 - Wheat and soy noodle products.  

Code of Federal Regulations, 2010 CFR

...2010-04-01 false Wheat and soy noodle products. 139.180 Section 139...FOOD FOR HUMAN CONSUMPTION MACARONI AND NOODLE PRODUCTS Requirements for Specific Standardized Macaroni and Noodle Products § 139.180 Wheat and...

2010-04-01

341

21 CFR 139.180 - Wheat and soy noodle products.  

Code of Federal Regulations, 2010 CFR

...2009-04-01 false Wheat and soy noodle products. 139.180 Section 139...FOOD FOR HUMAN CONSUMPTION MACARONI AND NOODLE PRODUCTS Requirements for Specific Standardized Macaroni and Noodle Products § 139.180 Wheat and...

2009-04-01

342

78 FR 27857 - United States Standards for Wheat  

Federal Register 2010, 2011, 2012, 2013

...facilitate the marketing of wheat. DATES...groups, industry associations, and exporters...grounds. North American Millers Association opposed the...domestic and export marketing of wheat. Executive...For North American Industry...

2013-05-13

343

Isolation of a wheat (Triticum aestivum L.) mutant in ABA 8?-hydroxylase gene: effect of reduced ABA catabolism on germination inhibition under field condition  

PubMed Central

Pre-harvest sprouting, the germination of mature seeds on the mother plant under moist condition, is a serious problem in cereals. To investigate the effect of reduced abscisic acid (ABA) catabolism on germination in hexaploid wheat (Triticum aestivum L.), we cloned the wheat ABA 8?-hydroxyase gene which was highly expressed during seed development (TaABA8?OH1) and screened for mutations that lead to reduced ABA catabolism. In a screen for natural variation, one insertion mutation in exon 5 of TaABA8?OH1 on the D genome (TaABA8?OH1-D) was identified in Japanese cultivars including ‘Tamaizumi’. However, a single mutation in TaABA8?OH1-D had no clear effect on germination inhibition in double haploid lines. In a screen for a mutation, one deletion mutant lacking the entire TaABA8?OH1 on the A genome (TaABA8?OH1-A), TM1833, was identified from gamma-ray irradiation lines of ‘Tamaizumi’. TM1833 (a double mutant in TaABA8?OH1-A and TaABA8?OH1-D) showed lower TaABA8?OH1 expression, higher ABA content in embryos during seed development under field condition and lower germination than those in ‘Tamaizumi’ (a single mutant in TaABA8?OH1-D). These results indicate that reduced ABA catabolism through mutations in TaABA8?OH1 may be effective in germination inhibition in field-grown wheat.

Chono, Makiko; Matsunaka, Hitoshi; Seki, Masako; Fujita, Masaya; Kiribuchi-Otobe, Chikako; Oda, Shunsuke; Kojima, Hisayo; Kobayashi, Daisuke; Kawakami, Naoto

2013-01-01

344

Isolation of a wheat (Triticum aestivum L.) mutant in ABA 8'-hydroxylase gene: effect of reduced ABA catabolism on germination inhibition under field condition.  

PubMed

Pre-harvest sprouting, the germination of mature seeds on the mother plant under moist condition, is a serious problem in cereals. To investigate the effect of reduced abscisic acid (ABA) catabolism on germination in hexaploid wheat (Triticum aestivum L.), we cloned the wheat ABA 8'-hydroxyase gene which was highly expressed during seed development (TaABA8'OH1) and screened for mutations that lead to reduced ABA catabolism. In a screen for natural variation, one insertion mutation in exon 5 of TaABA8'OH1 on the D genome (TaABA8'OH1-D) was identified in Japanese cultivars including 'Tamaizumi'. However, a single mutation in TaABA8'OH1-D had no clear effect on germination inhibition in double haploid lines. In a screen for a mutation, one deletion mutant lacking the entire TaABA8'OH1 on the A genome (TaABA8'OH1-A), TM1833, was identified from gamma-ray irradiation lines of 'Tamaizumi'. TM1833 (a double mutant in TaABA8'OH1-A and TaABA8'OH1-D) showed lower TaABA8'OH1 expression, higher ABA content in embryos during seed development under field condition and lower germination than those in 'Tamaizumi' (a single mutant in TaABA8'OH1-D). These results indicate that reduced ABA catabolism through mutations in TaABA8'OH1 may be effective in germination inhibition in field-grown wheat. PMID:23641187

Chono, Makiko; Matsunaka, Hitoshi; Seki, Masako; Fujita, Masaya; Kiribuchi-Otobe, Chikako; Oda, Shunsuke; Kojima, Hisayo; Kobayashi, Daisuke; Kawakami, Naoto

2013-03-01

345

The utility of the nontranscribed spacer of 5S rDNA units grouped into unit classes assigned to haplomes - a test on cultivated wheat and wheat progenitors  

Microsoft Academic Search

Data is presented on the evolutionary dynamics of non-transcribed spacers (NTSs) of 5S rRNA genes in some diploid and polyploid Triticum and Aegilops species. FISH experiments with probes representing different unit classes revealed presence and (or) absence of these sequences in genomes or separate chromosomes of the species. Among the three diploid species only Aegilops speltoides has all of the

Bernard R. Baum; L. Grant Bailey; Alexander Belyayev; Olga Raskina; Eviatar Nevo

2004-01-01

346

Effects of Wheat Starch and Gluten on Tortilla Texture 1  

Microsoft Academic Search

Cereal Chem. 76(5):807-810 Wheat starches were isolated from three wheat flours. Two vital wheat glutens, one from a commercial source and another one isolated from straight-grade flour, were combined with wheat starches to form recon- stituted flours with a protein level of 10%. Several characteristics of tortillas made with the hot-press met hod were measured. No significant difference (P <

Linfeng Wang; Rolando A. Flores

1999-01-01

347

Technological properties of bakers’ yeasts in durum wheat semolina dough  

Microsoft Academic Search

Properties of 13 Saccharomyces cerevisiae strains isolated from different sources (traditional sourdoughs, industrial baking yeasts etc.) were studied in dough produced\\u000a with durum wheat (Sicilian semolina, variety Mongibello). Durum wheat semolina and durum wheat flour are products prepared\\u000a from grain of durum wheat (Triticum durum Desf.) by grinding or milling processes in which the bran and germ are essentially\\u000a removed

Virgilio Giannone; Chiara Longo; Arcangelo Damigella; Domenico Raspagliesi; Alfio Spina; Massimo Palumbo

2010-01-01

348

7 CFR 810.2201 - Definition of wheat.  

Code of Federal Regulations, 2010 CFR

...2009-01-01 2009-01-01 false Definition of wheat. 810.2201 Section 810.2201 Agriculture...STANDARDS FOR GRAIN United States Standards for Wheat Terms Defined § 810.2201 Definition of wheat. Grain that, before the removal of...

2009-01-01

349

7 CFR 810.2201 - Definition of wheat.  

Code of Federal Regulations, 2010 CFR

...2010-01-01 2010-01-01 false Definition of wheat. 810.2201 Section 810.2201 Agriculture...STANDARDS FOR GRAIN United States Standards for Wheat Terms Defined § 810.2201 Definition of wheat. Grain that, before the removal of...

2010-01-01

350

Acetic acid pulping of wheat straw under atmospheric pressure  

Microsoft Academic Search

Atmospheric acetic acid pulping of wheat straw was carried out. Pulping conditions and their effects on pulp properties were investigated in detail, and a comparison between acetic acid (AcOH) pulp and soda-anthraquinone (AQ) pulps of wheat straw was made of the chemical com- position, strength, and fiber morphology of the pulps. Wheat straw was successfully pulped and fractionated into pulp

Xue-Jun PanYoshihiro Sano

1999-01-01

351

21 CFR 139.140 - Wheat and soy macaroni products.  

Code of Federal Regulations, 2010 CFR

...2010-04-01 2010-04-01 false Wheat and soy macaroni products. 139.140 Section 139...Macaroni and Noodle Products § 139.140 Wheat and soy macaroni products. (a) Wheat and soy macaroni products are the class of food...

2010-04-01

352

21 CFR 139.140 - Wheat and soy macaroni products.  

Code of Federal Regulations, 2010 CFR

...2009-04-01 2009-04-01 false Wheat and soy macaroni products. 139.140 Section 139...Macaroni and Noodle Products § 139.140 Wheat and soy macaroni products. (a) Wheat and soy macaroni products are the class of food...

2009-04-01

353

Identification of New Sources of Aluminum Resistance in Wheat  

Technology Transfer Automated Retrieval System (TEKTRAN)

Aluminum (Al) toxicity is a major constraint for wheat production in acidic soils. An Al-resistance gene on chromosome 4DL that traces to Brazilian wheat has been extensively studied, and can provide partial protection from Al damage. To identify potentially new sources of Al resistance, 590 wheat a...

354

Valuing local wheat landraces for agrobiodiversity conservation in Northeast Turkey  

Microsoft Academic Search

The perception of farmers, scientists and government officials regarding the conservation of a wheat (Triticum aestivum L.) landrace in a Turkish village is examined. Agricultural development and the reasons why the Northeast of Turkey is marginal in terms of wheat production are discussed. The de facto conservation of the local wheat landrace is analyzed in light of stakeholders’ opinions on

Douglas Bardsley; Ian Thomas

2005-01-01

355

NUTRITIONAL COMPONENTS OF SUPERCRITICAL CARBON DIOXIDE EXTRACTED WHEAT GERM OIL  

Microsoft Academic Search

Wheat germ is one of the richest natural sources of alpha tocopherol, which possesses vitamin E activity. Wheat germ oil has a number of health benefits such as reducing plasma and liver cholesterol levels, improving physical endurance\\/fitness and delaying aging. The health benefits of wheat germ oil are attributed to its high vitamin E, polyunsaturat ed fatty acid and long

Nurhan Turgut Dunford; Jose L. Martinez

356

Wheat rusts in the United States in 2011  

Technology Transfer Automated Retrieval System (TEKTRAN)

Wheat stem rust (Puccinia graminis tritici) was found in Texas, Louisiana, Oklahoma, Kansas, Nebraska, North Dakota, Minnesota, Arkansas, Missouri, Kentucky, Illinois, Indiana, Wisconsin and Michigan in 2011. Nationally, wheat only incurred a trace loss due to wheat stem rust. Race QFCS was the most...

357

Milling and Baking Qualities of Weathered Soft Wheats  

Technology Transfer Automated Retrieval System (TEKTRAN)

The effects of weathered/pre-harvested sprouted soft wheats on milling and baking qualities were explored with 12 soft wheat cultivars. Weathered/pre-harvested sprouted wheats increased break flour yield, but significantly decreased test weight. The relationships between falling number and a-amylas...

358

ESTIMATION OF HEAT DAMAGE IN HARD RED WINTER WHEAT CULTIVARS  

Technology Transfer Automated Retrieval System (TEKTRAN)

Heat damage occurs during the artifical drying of newly harvested wheat or at high storage temperatures. Wheat proteins can be denatured by kernel heat damage during storage or during wheat milling process. Protein denaturation limits their functional (visco eleastic) properties in flour dough and...

359

Phenolics in the Bran of Waxy Wheat and Triticale Lines  

Technology Transfer Automated Retrieval System (TEKTRAN)

The present study was designed to determine total phenolic acid contents (TPC) and compositions of bran from newly developed near-isogenic waxy wheat and triticale translocation lines. Two sets of near-isogenic waxy wheats, Svevo (durum) and N11 (bread wheat), consisting of partial and waxy null li...

360

Impacts of climate change on winter wheat production in China  

Microsoft Academic Search

Climate is changing due to increasing concentration of greenhouse gases, affecting many economic sectors, e.g. agriculture and forestry. Agriculture is a basic sector, especially to China with the most population. Wheat is the second most important staple crops in China. Therefore, assessment of the impacts of climate change on winter wheat is essential for policy maker and wheat producers for

Zhan Tian; Zhiqiang Gao; Yinlong Xu; Hua Chen

2005-01-01

361

Mixed Nitrogen Nutrition and Productivity of Wheat Grown in Hydroponics  

Microsoft Academic Search

The objective of this study was to study the effects of nitrogen (N) supplied as either mixtures of NOa and NH. or as all NOa on the final yield of spring wheat. Two separate greenhouse experiments evaluated the durum spring wheat (Triticum durum L.) cultivar 'Inbar' in 1986, and the hard red spring wheat (Triticum aestu'um L.) cultivar' Len' in

J. A. HEBERER

362

1999 PRICING PERFORMANCE OF MARKET ADVISORY SERVIVES FOR WHEAT  

Microsoft Academic Search

The purpose of this research report is to present an evaluation of advisory service pricing performance in the 1999 crop year for wheat. Specifically, the average price received by a subscriber to an advisory service is calculated for wheat crop harvested in 1999. The average net advisory price across all 23 wheat programs in 1999 is $2.64 per bushel, $0.04

Joao Martines-Filho; Darrel L. Good; Scott H. Irwin

2001-01-01

363

Wheat Flour Proteins as Affected by Transglutaminase and Glucose Oxidase  

Microsoft Academic Search

Cereal Chem. 80(1):52-55 Enzymes are good tool to modify wheat proteins by creating new bonds between the protein chains. In this study, the effect of the addition of glucose oxidase (GO) and transglutaminase (TG) on the wheat flour proteins is presented. The modification of wheat proteins was determined by analyzing the changes in gluten quality, alveograph parameters, and protein modifications.

C. M. Rosell; J. Wang; S. Aja; S. Bean; G. Lookhart

2003-01-01

364

21 CFR 139.138 - Whole wheat macaroni products.  

Code of Federal Regulations, 2013 CFR

...macaroni products by § 139.110(a), (f)(2), (f)(3), and (g), except that: (1) Whole wheat flour or whole durum wheat flour or both are used as the sole wheat ingredient; and (2) None of the optional ingredients permitted...

2013-04-01

365

Investigating the role of ABA signaling in wheat drought tolerance  

Technology Transfer Automated Retrieval System (TEKTRAN)

Allohexaploid wheat (Triticum aestivum L.) is one of the three major cereal crops supporting human nutrition. Because wheat is often grown under dryland conditions, it is subject to losses as a result of drought stress. This study examines the role of the plant hormone ABA is wheat responses to wate...

366

Alien introgression for FHB resistance in wheat - challenges and strategies  

Microsoft Academic Search

Over one thousand accessions of wheat relatives at different ploidy levels and wheat-alien species derivatives with varied chromosome constitutions were evaluated for Fusarium head blight (FHB) resistance. FHB resistance identified from the relatives and derivatives were introgressed into adapted bread and durum wheat backgrounds using several strategies. A number of resistant introgression lines that contain minimal alien chromatin and do

Cai X; Xu SS; Oliver RE; Zhang Q; Stack RW; Zhong S; Friesen TL; Halley S

367

An Experimental Study and Mathematical Simulation of Wheat Drying  

Microsoft Academic Search

A fixed-bed dryer was designed and constructed and drying experiments with fixed beds of wheat were carried out under various conditions of drying air with wheat of several initial moisture contents. The air temperature and moisture content of wheat at various levels within the beds were measured periodically. A computer program based on energy and mass balances was developed to

N. H. Abu-Hamdeh; A. M. Othman

2004-01-01

368

Structure and morphology of cellulose in wheat straw  

Microsoft Academic Search

The structure and morphology of cellulose extracted from wheat were studied. It was found that the extraction process is effective and hemicelluloses and lignin can be extracted completely. Cellulose in wheat straw was identified as cellulose I allomorph with low crystallinity and the crystallinity of cellulose from different parts of the wheat straw has little difference. There was no metastable

Ruigang Liu; Hui Yu; Yong Huang

2005-01-01

369

SENSORY ANALYSIS OF WHOLE WHEAT/SOY FLOUR BREADS  

Technology Transfer Automated Retrieval System (TEKTRAN)

The effects of dough formulation on wheat/soy bread taste and texture were studied in order to design a low cost, high protein bread which could help reduce hunger in the U.S. and abroad. Breads contained 0-40% defatted soy flour, 30-100% whole wheat flour and 0-30% white wheat flour and were prepa...

370

Resolving the Edaphic Conflict in Rice-wheat system  

Microsoft Academic Search

Traditionally rice is transplanted in puddled flooded field and wheat is sown after pulverizing the soil. This reflects to a tillage conflict in traditional soil management for rice and its consequent deleterious effects for the succeeding wheat crop in the rice-wheat system. A study consisting of two experiments (both being exactly the same in design and implementation) was conducted to

Muhammad Farooq; Shahzad M. A. Basra

371

WHEAT FLOUR PROTEINS AS AFFECTED BY TRANSGLUTAMINASE AND GLUCOSE OXIDASE  

Technology Transfer Automated Retrieval System (TEKTRAN)

Enzymes are good tools to modify wheat proteins by creating new bonds between the protein chains. In this study, the effect of the addition of glucose oxidase (GO) and transglutaminase (TG) on the wheat flour proteins is presented. The modification of wheat proteins was determined by analyzing the...

372

HARD RED SPRING WHEAT QUALITY REPORT: 2000/2001 CROP.  

Technology Transfer Automated Retrieval System (TEKTRAN)

Commercially grown cultivars and experimental lines of hard red spring wheat were grown by breeders at cooperative experiment stations throughout the major spring wheat growing regions of the United States. Hard spring wheat was tested for kernel, milling, flour, dough, and baking quality. In 2000...

373

A New Model for Progenitor Systems of Type IA Supernovae  

Microsoft Academic Search

We propose a new model for progenitor systems of Type Ia supernovae. The model consists of an accreting white dwarf and a lobe-filling, low-mass red giant. When the mass accretion rate exceeds a certain critical rate, there is no static envelope solution on the white dwarf. For this case, we find a new strong wind solution, which replaces the static

I. Hachisu; M. Kato; K. Nomoto

1996-01-01

374

Colliding Stellar Winds in Type Ia Supernova Progenitors  

Microsoft Academic Search

The characteristics of the progenitors of Type Ia supernovae (SNe) are unknown. One viable theory involves close binary systems containing a white dwarf and a companion donor star. Such systems are expected to have substantial circumstellar material (CSM) at the time of the supernova explosion, yet almost all Ia SNe show no signs of circumstellar interaction. We want to know

Aaron Marcus; J. M. Blondin; K. J. Borkowski; S. P. Reynolds

2010-01-01

375

Progenitors of type Ia supernovae in elliptical galaxies  

Microsoft Academic Search

Although there is a nearly universal agreement that type Ia supernovae are associated with the thermonuclear disruption of a CO white dwarf, the exact nature of their progenitors is still unknown. The single degenerate scenario envisages a white dwarf accreting matter from a non-degenerate companion in a binary system. Nuclear energy of the accreted matter is released in the form

M. Gilfanov; Á. Bogdán

2011-01-01

376

Value added: Neural progenitor cells suppress inflammation and autoimmunity  

PubMed Central

Summary Neural progenitor cells (NPCs) can repair damaged myelin in neurodegenerative diseases. In this issue of Immunity, Cao et al., 2011, report that NPCs also produce the cytokine LIF, which suppresses Th17 cell-driven inflammation and autoimmunity by upregulating the protein Socs3.

Awasthi, Amit; Kuchroo, Vijay K

2011-01-01

377

Influence of BMI on level of circulating progenitor cells.  

PubMed

Obesity complicates a number of diseases through mechanisms that are poorly defined. Mobilization and recruitment of progenitor cells to pathological sites is an important factor in disease progression. Here, we analyzed the influence of obesity on the systemic circulation of CD34(+) cell populations and correlated frequencies of cells displaying previously established cell marker signatures with the BMI. Comparative analysis of peripheral blood mononuclear cells (PBMC) from 12 nonobese (BMI <30 kg/m(2)) and 14 obese (BMI >30 kg/m(2)) disease-free donors by flow cytometry revealed that obesity is associated with a fivefold increased frequency of circulating progenitor cells (CPC), a population consisting of hematopoietic and endothelial precursors. Our data also indicate that obesity is associated with increased frequency of circulating mesenchymal stromal progenitor cells (MSC). In contrast, the frequencies of mature endothelial cells (EC) and CD34-bright leukocytes are unaffected by obesity. Combined, our results indicate that obesity promotes mobilization of progenitor cells, which may have clinical relevance. PMID:21293449

Bellows, Charles F; Zhang, Yan; Simmons, Paul J; Khalsa, Amrit S; Kolonin, Mikhail G

2011-02-03

378

Influence of BMI on Level of Circulating Progenitor Cells  

PubMed Central

Obesity complicates a number of diseases through mechanisms that are poorly defined. Mobilization and recruitment of progenitor cells to pathological sites is an important factor in disease progression. Here, we analyzed the influence of obesity on the systemic circulation of CD34+ cell populations and correlated frequencies of cells displaying previously established cell marker signatures with the BMI. Comparative analysis of peripheral blood mononuclear cells (PBMC) from 12 nonobese (BMI <30 kg/m2) and 14 obese (BMI >30 kg/m2) disease-free donors by flow cytometry revealed that obesity is associated with a fivefold increased frequency of circulating progenitor cells (CPC), a population consisting of hematopoietic and endothelial precursors. Our data also indicate that obesity is associated with increased frequency of circulating mesenchymal stromal progenitor cells (MSC). In contrast, the frequencies of mature endothelial cells (EC) and CD34-bright leukocytes are unaffected by obesity. Combined, our results indicate that obesity promotes mobilization of progenitor cells, which may have clinical relevance.

Bellows, Charles F.; Zhang, Yan; Simmons, Paul J.; Khalsa, Amrit S.; Kolonin, Mikhail G.

2011-01-01

379

Gravitational settling in pulsating subdwarf B stars and their progenitors  

Microsoft Academic Search

Context. Diffusion of atoms can be important during quiescent phases of stellar evolution. Particularly in the very thin inert envelopes of subdwarf B stars, diffusive movements will considerably change the envelope structure and the surface abundances on a short timescale. Also, the subdwarfs will inherit the effects of diffusion in their direct progenitors, namely giants near the tip of the

Haili Hu; E. Glebbeek; A. A. Thoul; M.-A. Dupret; R. J. Stancliffe; G. A. Nelemans; C. Aerts

2010-01-01

380

Renal progenitors: an evolutionary conserved strategy for kidney regeneration.  

PubMed

Following kidney injury, repair can result in functional tissue becoming a patch of cells and disorganized extracellular matrix--a scar--or it can recapitulate the original tissue architecture through the process of regeneration. Regeneration can potentially occur in all animal species and humans. Indeed, the repair of portions of the existing nephron after tubular damage, a response that has been designated classically as cellular regeneration, is conserved in all animal species from the ancestral phases of evolution. By contrast, another type of regenerative response--nephron neogenesis--has been described in lower branches of the animal kingdom, but does not occur in adult mammals. Converging evidence suggests that a renal progenitor system is present in the adult kidney across different stages of evolution, with renal progenitors having been identified as the main drivers of kidney regenerative responses in fish, insects, rodents and humans. In this Review, we describe similarities and differences between the renal progenitor systems through evolution, and propose explanations for how progressive kidney adaptation to environmental changes both required and permitted neonephrogenesis to be given up and for cellular regeneration to be retained as the main regenerative strategy. Understanding the mechanisms that drive renal progenitor growth and differentiation represent the key step for modulating this potential for therapeutic purposes. PMID:23338209

Romagnani, Paola; Lasagni, Laura; Remuzzi, Giuseppe

2013-01-22

381

Differential Notch signalling distinguishes neural stem cells from intermediate progenitors  

Microsoft Academic Search

During brain development, neurons and glia are generated from a germinal zone containing both neural stem cells (NSCs) and more limited intermediate neural progenitors (INPs). The signalling events that distinguish between these two proliferative neural cell types remain poorly understood. The Notch signalling pathway is known to maintain NSC character and to inhibit neurogenesis, although little is known about the

Ken-Ichi Mizutani; Keejung Yoon; Louis Dang; Akinori Tokunaga; Nicholas Gaiano

2007-01-01

382

Smooth Muscle Progenitor Cells: Friend or Foe in Vascular Disease?  

Microsoft Academic Search

The origin of vascular smooth muscle cells that accumulate in the neointima in vascular diseases such as trans- plant arteriosclerosis, atherosclerosis and restenosis remains subject to much debate. Smooth muscle cells are a highly heterogeneous cell population with different characteristics and markers, and distinct phenotypes in physiological and pathological conditions. Several studies have reported a role for bone marrow-derived progenitor

Olivia van Oostrom; Joost O. Fledderus; Dominique de Kleijn; Gerard Pasterkamp; Marianne C. Verhaar

2009-01-01

383

Regulation of Mammary Progenitor Cells by p53 and Parity.  

National Technical Information Service (NTIS)

Breast cancer is the most common tumor among women with inherited mutations in the p53 gene (Li-Fraumeni syndrome). The tumors represent the basal-like subtype which has been suggested to originate from mammary stem/progenitor cells. In mouse mammary epit...

D. J. Jerry L. Tao

2011-01-01

384

Secondary Sphere Formation Enhances the Functionality of Cardiac Progenitor Cells  

PubMed Central

Loss of cardiomyocytes impairs cardiac function after myocardial infarction (MI). Recent studies suggest that cardiac stem/progenitor cells could repair the damaged heart. However, cardiac progenitor cells are difficult to maintain in terms of purity and multipotency when propagated in two-dimensional culture systems. Here, we investigated a new strategy that enhances potency and enriches progenitor cells. We applied the repeated sphere formation strategy (cardiac explant ? primary cardiosphere (CS) formation ? sphere-derived cells (SDCs) in adherent culture condition ? secondary CS formation by three-dimensional culture). Cells in secondary CS showed higher differentiation potentials than SDCs. When transplanted into the infarcted myocardium, secondary CSs engrafted robustly, improved left ventricular (LV) dysfunction, and reduced infarct sizes more than SDCs did. In addition to the cardiovascular differentiation of transplanted secondary CSs, robust vascular endothelial growth factor (VEGF) synthesis and secretion enhanced neovascularization in the infarcted myocardium. Microarray pathway analysis and blocking experiments using E-selectin knock-out hearts, specific chemicals, and small interfering RNAs (siRNAs) for each pathway revealed that E-selectin was indispensable to sphere initiation and ERK/Sp1/VEGF autoparacrine loop was responsible for sphere maturation. These results provide a simple strategy for enhancing cellular potency for cardiac repair. Furthermore, this strategy may be implemented to other types of stem/progenitor cell-based therapy.

Cho, Hyun-Jai; Lee, Ho-Jae; Youn, Seock-Won; Koh, Seok-Jin; Won, Joo-Yun; Chung, Yeon-Ju; Cho, Hyun-Ju; Yoon, Chang-Hwan; Lee, Sae-Won; Lee, Eun Ju; Kwon, Yoo-Wook; Lee, Hae-Young; Lee, Sang Hun; Ho, Won-Kyung; Park, Young-Bae; Kim, Hyo-Soo

2012-01-01

385

Natural killer-cell differentiation by myeloid progenitors  

PubMed Central

Because lymphoid progenitors can give rise to natural killer (NK) cells, NK ontogeny has been considered to be exclusively lymphoid. Here, we show that rare human CD34+ hematopoietic progenitors develop into NK cells in vitro in the presence of cytokines (interleukin-7, interleukin-15, stem cell factor, and fms-like tyrosine kinase-3 ligand). Adding hydrocortisone and stromal cells greatly increases the frequency of progenitor cells that give rise to NK cells through the recruitment of myeloid precursors, including common myeloid progenitors and granulocytic-monocytic precursors to the NK-cell lineage. WNT signaling was involved in this effect. Cells at more advanced stages of myeloid differentiation (with increasing expression of CD13 and macrophage colony-stimulating factor receptor [M-CSFR]) could also differentiate into NK cells in the presence of cytokines, stroma, and hydrocortisone. NK cells derived from myeloid precursors (CD56?CD117+M-CSFR+) showed more expression of killer immunoglobulin-like receptors, a fraction of killer immunoglobulin–like receptor-positive–expressing cells that lacked NKG2A, a higher cytotoxicity compared with CD56?CD117+M-CSFR? precursor-derived NK cells and thus resemble the CD56dim subset of NK cells. Collectively, these studies show that NK cells can be derived from the myeloid lineage.

Grzywacz, Bartosz; Kataria, Nandini; Kataria, Niketa; Blazar, Bruce R.; Miller, Jeffrey S.

2011-01-01

386

?4 Integrin signaling induces expansion of prostate tumor progenitors  

PubMed Central

The contextual signals that regulate the expansion of prostate tumor progenitor cells are poorly defined. We found that a significant fraction of advanced human prostate cancers and castration-resistant metastases express high levels of the ?4 integrin, which binds to laminin-5. Targeted deletion of the signaling domain of ?4 inhibited prostate tumor growth and progression in response to loss of p53 and Rb function in a mouse model of prostate cancer (PB-TAg mice). Additionally, it suppressed Pten loss-driven prostate tumorigenesis in tissue recombination experiments. We traced this defect back to an inability of signaling-defective ?4 to sustain self-renewal of putative cancer stem cells in vitro and proliferation of transit-amplifying cells in vivo. Mechanistic studies indicated that mutant ?4 fails to promote transactivation of ErbB2 and c-Met in prostate tumor progenitor cells and human cancer cell lines. Pharmacological inhibition of ErbB2 and c-Met reduced the ability of prostate tumor progenitor cells to undergo self-renewal in vitro. Finally, we found that ?4 is often coexpressed with c-Met and ErbB2 in human prostate cancers and that combined pharmacological inhibition of these receptor tyrosine kinases exerts antitumor activity in a mouse xenograft model. These findings indicate that the ?4 integrin promotes prostate tumorigenesis by amplifying ErbB2 and c-Met signaling in tumor progenitor cells.

Yoshioka, Toshiaki; Otero, Javier; Chen, Yu; Kim, Young-Mi; Koutcher, Jason A.; Satagopan, Jaya; Reuter, Victor; Carver, Brett; de Stanchina, Elisa; Enomoto, Katsuhiko; Greenberg, Norman M.; Scardino, Peter T.; Scher, Howard I.; Sawyers, Charles L.; Giancotti, Filippo G.

2013-01-01

387

Characterization of Progenitor Cells during Canine Retinal Development  

PubMed Central

We identify the presence of progenitor cells during retinal development in the dog, as this species represents a natural model for studying several breed-specific degenerative retinal disorders. Antibodies to detected progenitor cells (Pax6, C-kit, and nestin) and ganglion cells (BDNF, Brn3a, and Thy1) were used in combination with H3 for the purpose of identifying proliferating cells. Pax6, nestin, C-kit, and H3 were localized mainly in the neuroblastic layer of the retina during the embryonic stage. During the fetal stage, proteins were expressed in the inner neuroblastic layer (INL) as well as in the outer neuroblastic layer; BDNF, Thy1, and Brn3a were also expressed in the INL. During the neonatal stage only C-kit was not expressed. Proliferating cells were present in both undifferentiated and differentiated retina. These results suggest that, during canine retinogenesis, progenitor cells are distributed along the retina and some of these cells remain as progenitor cells of the ganglion cells during the first postnatal days.

Avila-Garcia, Mallely; Garcia-Sanchez, Gustavo; Lira-Romero, Esmeralda; Moreno-Mendoza, Norma

2012-01-01

388

Engraftable Neural Progenitor and Stem Cells for Brain Tumor Therapy.  

National Technical Information Service (NTIS)

One of the impediments to the treatment of some human brain tumors (e.g. gliomas) has been the degree to which they expand, migrate widely, and infiltrate normal tissue. We demonstrate that a clone of multipotent neural progenitor stem cells, when implant...

E. Y. Snyder K. S. Aboody W. P. Lynch X. O. Breakefield

2004-01-01

389

Fine structure of progenitor cells in early ectopic human embryos.  

PubMed

This study has documented the major types of lineage progenitor cells at the second level of cell differentiation after the establishment of the primary germ layers in ectopic human embryos in vivo. These correspond to stages 8 and 9 of embryogenesis (weeks 3-4) in the Carnegie collection. The aim of this study was to provide images of fine structure of tissue progenitor cells to compare them with current imaging of their equivalent stem cells identified using fluorescent stem cell markers. These include neural, mesenchymal, endodermal, ectodermal (epidermal) and haematopoietic progenitor cells, including those for amniotic, yolk sac and chorionic tissues that are used in current stem cell research. Neural induction by the notochord has been imaged. This study should give valuable clues to understand the pattern of cell differentiation of embryonic stem cells (ESC) in vitro, which are more or less mimicked in ESC colonies, embryoid bodies and neurospheres as documented in the literature. The fine structure of week-3 and week-4 human ectopic embryos is presented to demonstrate progenitor tissue cells that will eventually form the brain, spinal cord, skin, gut, heart, blood, muscle, bone and other tissues of the human body later on in development. These images should help stem cell researchers using fluorescent markers and other techniques to identify embryonic and adult stem cells in culture. PMID:22796234

Sathananthan, Henry; Selvaraj, Kamala; Clark, Joan

2012-06-09

390

Adult Spinal Cord Radial Glia Display a Unique Progenitor Phenotype  

PubMed Central

Radial glia (RG) are primarily embryonic neuroglial progenitors that express Brain Lipid Binding Protein (Blbp a.k.a. Fabp7) and Glial Fibrillary Acidic Protein (Gfap). We used these transcripts to demarcate the distribution of spinal cord radial glia (SCRG) and screen for SCRG gene expression in the Allen Spinal Cord Atlas (ASCA). We reveal that neonatal and adult SCRG are anchored in a non-ventricular niche at the spinal cord (SC) pial boundary, and express a “signature” subset of 122 genes, many of which are shared with “classic” neural stem cells (NSCs) of the subventricular zone (SVZ) and SC central canal (CC). A core expressed gene set shared between SCRG and progenitors of the SVZ and CC is particularly enriched in genes associated with human disease. Visualizing SCRG in a Fabp7-EGFP reporter mouse reveals an extensive population of SCRG that extend processes around the SC boundary and inwardly (through) the SC white matter (WM), whose abundance increases in a gradient from cervical to lumbar SC. Confocal analysis of multiple NSC-enriched proteins reveals that postnatal SCRG are a discrete and heterogeneous potential progenitor population that become activated by multiple SC lesions, and that CC progenitors are also more heterogeneous than previously appreciated. Gene ontology analysis highlights potentially unique regulatory pathways that may be further manipulated in SCRG to enhance repair in the context of injury and SC disease.

Kennedy, Timothy E.; Tetzlaff, Wolfram; Glattfelder, Katie J.; Dalley, Rachel A.; Puchalski, Ralph B.; Jones, Allan R.; Roskams, A. Jane

2011-01-01

391

Adult spinal cord radial glia display a unique progenitor phenotype.  

PubMed

Radial glia (RG) are primarily embryonic neuroglial progenitors that express Brain Lipid Binding Protein (Blbp a.k.a. Fabp7) and Glial Fibrillary Acidic Protein (Gfap). We used these transcripts to demarcate the distribution of spinal cord radial glia (SCRG) and screen for SCRG gene expression in the Allen Spinal Cord Atlas (ASCA). We reveal that neonatal and adult SCRG are anchored in a non-ventricular niche at the spinal cord (SC) pial boundary, and express a "signature" subset of 122 genes, many of which are shared with "classic" neural stem cells (NSCs) of the subventricular zone (SVZ) and SC central canal (CC). A core expressed gene set shared between SCRG and progenitors of the SVZ and CC is particularly enriched in genes associated with human disease. Visualizing SCRG in a Fabp7-EGFP reporter mouse reveals an extensive population of SCRG that extend processes around the SC boundary and inwardly (through) the SC white matter (WM), whose abundance increases in a gradient from cervical to lumbar SC. Confocal analysis of multiple NSC-enriched proteins reveals that postnatal SCRG are a discrete and heterogeneous potential progenitor population that become activated by multiple SC lesions, and that CC progenitors are also more heterogeneous than previously appreciated. Gene ontology analysis highlights potentially unique regulatory pathways that may be further manipulated in SCRG to enhance repair in the context of injury and SC disease. PMID:21931744

Petit, Audrey; Sanders, Ashley D; Kennedy, Timothy E; Tetzlaff, Wolfram; Glattfelder, Katie J; Dalley, Rachel A; Puchalski, Ralph B; Jones, Allan R; Roskams, A Jane

2011-09-12

392

TYPE IIb SUPERNOVAE WITH COMPACT AND EXTENDED PROGENITORS  

SciTech Connect

The classic example of a Type IIb supernova is SN 1993J, which had a cool extended progenitor surrounded by a dense wind. There is evidence for another category of Type IIb supernova that has a more compact progenitor with a lower density, probably fast, wind. Distinguishing features of the compact category are weak optical emission from the shock heated envelope at early times, nonexistent or very weak H emission in the late nebular phase, rapidly evolving radio emission, rapid expansion of the radio shell, and expected nonthermal as opposed to thermal X-ray emission. Type IIb supernovae that have one or more of these features include SNe 1996cb, 2001ig, 2003bg, 2008ax, and 2008bo. All of these with sufficient radio data (the last four) show evidence for presupernova wind variability. We estimate a progenitor envelope radius {approx}1 x 10{sup 11} cm for SN 2008ax, a value consistent with a compact Wolf-Rayet progenitor. Supernovae in the SN 1993J extended category include SN 2001gd and probably the Cas A supernova. We suggest that the compact Type IIb events be designated Type cIIb and the extended ones Type eIIb. The H envelope mass dividing these categories is {approx}0.1 M {sub sun}.

Chevalier, Roger A. [Department of Astronomy, University of Virginia, P.O. Box 400325, Charlottesville, VA 22904-4325 (United States); Soderberg, Alicia M. [Harvard-Smithsonian Center for Astrophysics, 60 Garden Street, MS-51, Cambridge, MA 02138 (United States)], E-mail: rac5x@virginia.edu

2010-03-01

393

Immortalized neural progenitor cells for CNS gene transfer and repair  

Microsoft Academic Search

Immortalized multipotent neural stem and progenitor cells have emerged as a highly convenient source of tissue for genetic manipulation and ex vivo gene transfer to the CNS. Recent studies show that these cells, which can be maintained and genetically transduced as cell lines in culture, can survive, integrate and differentiate into both neurons and glia after transplantation to the intact

Alberto Martínez-Serrano; Anders Björklund

1997-01-01

394

Uncaria tomentosa stimulates the proliferation of myeloid progenitor cells  

Microsoft Academic Search

Ethnopharmacological relevanceThe Asháninkas, indigenous people of Peru, use cat's claw (Uncaria tomentosa) to restore health. Uncaria tomentosa has antioxidant activity and works as an agent to repair DNA damage. It causes different effects on cell proliferation depending on the cell type involved; specifically, it can stimulate the proliferation of myeloid progenitors and cause apoptosis of neoplastic cells. Neutropenia is the

Iria Farias; Maria do Carmo Araújo; Estevan Sonego Zimmermann; Sergio Luiz Dalmora; Aloisio Luiz Benedetti; Marcio Alvarez-Silva; Ana Carolina Cavazzin Asbahr; Gustavo Bertol; Júlia Farias; Maria Rosa Chitolina Schetinger

2011-01-01

395

The binary progenitor of Tycho Brahe's 1572 supernova  

Microsoft Academic Search

The brightness of type Ia supernovae, and their homogeneity as a class, makes them powerful tools in cosmology, yet little is known about the progenitor systems of these explosions. They are thought to arise when a white dwarf accretes matter from a companion star, is compressed and undergoes a thermonuclear explosion. Unless the companion star is another white dwarf (in

Pilar Ruiz-Lapuente; Fernando Comeron; Javier Méndez; Ramon Canal; Stephen J. Smartt; Alexei V. Filippenko; Robert L. Kurucz; Ryan Chornock; Ryan J. Foley; Vallery Stanishev; Rodrigo Ibata

2004-01-01

396

ADAR1 promotes malignant progenitor reprogramming in chronic myeloid leukemia.  

PubMed

The molecular etiology of human progenitor reprogramming into self-renewing leukemia stem cells (LSC) has remained elusive. Although DNA sequencing has uncovered spliceosome gene mutations that promote alternative splicing and portend leukemic transformation, isoform diversity also may be generated by RNA editing mediated by adenosine deaminase acting on RNA (ADAR) enzymes that regulate stem cell maintenance. In this study, whole-transcriptome sequencing of normal, chronic phase, and serially transplantable blast crisis chronic myeloid leukemia (CML) progenitors revealed increased IFN-? pathway gene expression in concert with BCR-ABL amplification, enhanced expression of the IFN-responsive ADAR1 p150 isoform, and a propensity for increased adenosine-to-inosine RNA editing during CML progression. Lentiviral overexpression experiments demonstrate that ADAR1 p150 promotes expression of the myeloid transcription factor PU.1 and induces malignant reprogramming of myeloid progenitors. Moreover, enforced ADAR1 p150 expression was associated with production of a misspliced form of GSK3? implicated in LSC self-renewal. Finally, functional serial transplantation and shRNA studies demonstrate that ADAR1 knockdown impaired in vivo self-renewal capacity of blast crisis CML progenitors. Together these data provide a compelling rationale for developing ADAR1-based LSC detection and eradication strategies. PMID:23275297

Jiang, Qingfei; Crews, Leslie A; Barrett, Christian L; Chun, Hye-Jung; Court, Angela C; Isquith, Jane M; Zipeto, Maria A; Goff, Daniel J; Minden, Mark; Sadarangani, Anil; Rusert, Jessica M; Dao, Kim-Hien T; Morris, Sheldon R; Goldstein, Lawrence S B; Marra, Marco A; Frazer, Kelly A; Jamieson, Catriona H M

2012-12-28

397

Plasma-assisted pretreatment of wheat straw.  

PubMed

O? generated in a plasma at atmospheric pressure and room temperature, fed with dried air (or oxygen-enriched dried air), has been used for the degradation of lignin in wheat straw to optimize the enzymatic hydrolysis and to get more fermentable sugars. A fixed bed reactor was used combined with a CO? detector and an online technique for O? measurement in the fed and exhaust gas allowing continuous measurement of the consumption of O?. This rendered it possible for us to determine the progress of the pretreatment in real time (online analysis). The process time can be adjusted to produce wheat straw with desired lignin content because of the online analysis. The O? consumption of wheat straw and its polymeric components, i.e., cellulose, hemicellulose, and lignin, as well as a mixture of these, dry as well as with 50% water, were studied. Furthermore, the process parameters dry matter content and milled particle size (the extent to which the wheat straw was milled) were investigated and optimized. The developed methodology offered the advantage of a simple and relatively fast (0.5-2 h) pretreatment allowing a dry matter concentration of 45-60%. FTIR measurements did not suggest any structural effects on cellulose and hemicellulose by the O? treatment. The cost and the energy consumption for lignin degradation of 100 g of wheat straw were calculated. PMID:20725803

Schultz-Jensen, Nadja; Leipold, Frank; Bindslev, Henrik; Thomsen, Anne Belinda

2010-08-20

398

Growth of Pleurotus ostreatus on wheat straw and wheat-grain-based media: biochemical aspects and preparation of mushroom inoculum  

Microsoft Academic Search

Mycelial growth, intracellular activity of proteases, laccases and ?-1,3-glucanases, and cytoplasmic protein were evaluated in the vegetative phase of Pleurotus ostreatus grown on wheat straw and in wheat-grain-based media in Petri dishes and in bottles. The productivity of the wheat straw and wheat-grain-based spawn in cylindrical polyethylene bags containing 5 kg of chopped straw was also determined. We observed high activity

E. Sainos; G. Díaz-Godínez; O. Loera; AM Montiel-González; C. Sánchez

2006-01-01

399

Molecular cytogenetic analysis of Agropyron elongatum chromatin in wheat germplasm specifying resistance to wheat streak mosaic virus  

Microsoft Academic Search

Three lines derived from wheat (6x) x Agropyron elongatum (10x) that are resistant to wheat streak mosaic virus (WSMV) were analyzed by chromosome pairing, banding, and in situ hybridization. Line CI15321 was identified as a disomic substitution line where wheat chromosome 1D is replaced by Ag. elongatum chromosome 1Ae-1. Line 87-94-1 is a wheat-Ag. elongatum ditelosomic addition 1Ae-1L. Line CI15322

J. Jiang; B. Friebe; H. S. Dhaliwal; T. J. Martin; B. S. Gill

1993-01-01

400

Development of consistently crossable wheat genotypes for alien wheat gene transfer through fine-mapping of the Kr1 locus  

Microsoft Academic Search

Breeders can force sexual hybridisation between wheat and related grass species to produce interspecific hybrids containing\\u000a a dihaploid set of wheat and related chromosomes. This facilitates the introgression of desirable genes into wheat from the\\u000a secondary gene pool. However, most elite European wheat varieties carry genes that suppress crossability, making the transfer\\u000a of novel traits from exotic germplasm into elite

Isabelle Bertin; Lesley Fish; Tracie N. Foote; Emilie Knight; John Snape; Graham Moore

2009-01-01

401

Individual Retinal Progenitor Cells Display Extensive Heterogeneity of Gene Expression  

PubMed Central

The development of complex tissues requires that mitotic progenitor cells integrate information from the environment. The highly varied outcomes of such integration processes undoubtedly depend at least in part upon variations among the gene expression programs of individual progenitor cells. To date, there has not been a comprehensive examination of these differences among progenitor cells of a particular tissue. Here, we used comprehensive gene expression profiling to define these differences among individual progenitor cells of the vertebrate retina. Retinal progenitor cells (RPCs) have been shown by lineage analysis to be multipotent throughout development and to produce distinct types of daughter cells in a temporal, conserved order. A total of 42 single RPCs were profiled on Affymetrix arrays. In situ hybridizations performed on both retinal sections and dissociated retinal cells were used to validate the results of the microarrays. An extensive amount of heterogeneity in gene expression among RPCs, even among cells isolated from the same developmental time point, was observed. While many classes of genes displayed heterogeneity of gene expression, the expression of transcription factors constituted a significant amount of the observed heterogeneity. In contrast to previous findings, individual RPCs were found to express multiple bHLH transcription factors, suggesting alternative models to those previously developed concerning how these factors may be coordinated. Additionally, the expression of cell cycle related transcripts showed differences among those associated with G2 and M, versus G1 and S phase, suggesting different levels of regulation for these genes. These data provide insights into the types of processes and genes that are fundamental to cell fate choices, proliferation decisions, and, for cells of the central nervous system, the underpinnings of the formation of complex circuitry.

Trimarchi, Jeffrey M.; Stadler, Michael B.; Cepko, Constance L.

2008-01-01

402

Update on the Cetus Polar Stream and Its Progenitor  

NASA Astrophysics Data System (ADS)

We trace the Cetus Polar Stream (CPS) with blue horizontal branch and red giant stars from Data Release 8 of the Sloan Digital Sky Survey. Using a larger data set than was available previously, we are able to refine the measured distance and velocity to this tidal debris star stream in the south Galactic cap. Assuming that the tidal debris traces the progenitor's orbit, we fit an orbit to the CPS and find that the stream is confined between ~24 and 36 kpc on a rather polar orbit inclined 87° to the Galactic plane. The eccentricity of the orbit is 0.20, and the period is ~700 Myr. If we instead matched N-body simulations to the observed tidal debris, these orbital parameters would change by 10% or less. The CPS stars travel in the opposite direction to those from the Sagittarius tidal stream in the same region of the sky. Through N-body models of satellites on the best-fitting orbit, and assuming that mass follows light, we show that the stream width, line-of-sight depth, and velocity dispersion imply a progenitor of >~ 108 M ?. However, the density of stars along the stream requires either a disruption time on the order of one orbit or a stellar population that is more centrally concentrated than the dark matter. We suggest that an ultrafaint dwarf galaxy progenitor could reproduce a large stream width and velocity dispersion without requiring a very recent deflection of the progenitor into its current orbit. We find that most Cetus stars have metallicities of –2.5 < [Fe/H] <–2.0, similar to the observed metallicities of the ultrafaint dwarfs. Our simulations suggest that the parameters of the dwarf galaxy progenitors, including their dark matter content, could be constrained by observations of their tidal tails through comparison of the debris with N-body simulations.

Yam, William; Carlin, Jeffrey L.; Newberg, Heidi Jo; Dumas, Julie; O'Malley, Erin; Newby, Matthew; Martin, Charles

2013-10-01

403

Characterization of progenitor domains in the developing mouse thalamus.  

PubMed

To understand the molecular basis of the specification of thalamic nuclei, we analyzed the expression patterns of various transcription factors and defined progenitor cell populations in the embryonic mouse thalamus. We show that the basic helix-loop-helix (bHLH) transcription factor Olig3 is expressed in the entire thalamic ventricular zone and the zona limitans intrathalamica (ZLI). Next, we define two distinct progenitor domains within the thalamus, which we name pTH-R and pTH-C, located caudal to the ZLI. pTH-R is immediately caudal to the ZLI and expresses Nkx2.2, Mash1, and Olig3. pTH-C is caudal to pTH-R and expresses Ngn1, Ngn2, and Olig3. Short-term lineage analysis of Olig3-, Mash1-, Ngn1-, and Ngn2-expressing progenitor cells as well as tracing the Pitx2 cell lineage suggests that pTH-C is the only major source of thalamic nuclei containing neurons that project to the cerebral cortex, whereas pTH-R and ZLI are likely to produce distinct postmitotic populations outside of the cortex-projecting part of the thalamus. To determine if pTH-C is composed of subdomains, we characterized expression of the homeodomain protein Dbx1 and the bHLH protein Olig2. We show that Dbx1 is expressed in caudodorsal-high to rostroventral-low gradient within pTH-C. Analysis of heterozygous Dbx1(nlslacZ) knockin mice demonstrated that Dbx1-expressing progenitors preferentially give rise to caudodorsal thalamic nuclei. Olig2 is expressed in an opposite gradient within pTH-C to that of Dbx1. These results establish the molecular heterogeneity within the progenitor cells of the thalamus, and suggest that such heterogeneity contributes to the specification of thalamic nuclei. PMID:17729296

Vue, Tou Yia; Aaker, Joshua; Taniguchi, Aya; Kazemzadeh, Christina; Skidmore, Jennifer M; Martin, Donna M; Martin, James F; Treier, Mathias; Nakagawa, Yasushi

2007-11-01

404

Stem and progenitor cells in biostructure of blood vessel walls.  

PubMed

Development of vascular and hematopoietic systems during organogenesis occurs at the same time. During vasculogenesis, a small part of cells does not undergo complete differentiation but stays on this level, "anchored" in tissue structures described as stem cell niches. The presence of blood vessels within tissue stem cell niches is typical and led to identification of niches and ensures that they are functioning. The three-layer biostructure of vessel walls for artery and vein, tunica: intima, media and adventitia, for a long time was defined as a mechanical barrier between vessel light and the local tissue environment. Recent findings from vascular biology studies indicate that vessel walls are dynamic biostructures, which are equipped with stem and progenitor cells, described as vascular wall-resident stem cells/progenitor cells (VW-SC/PC). Distinct zones for vessel wall harbor heterogeneous subpopulations of VW-SC/PC, which are described as "subendothelial or vasculogenic zones". Recent evidence from in vitro and in vivo studies show that prenatal activity of stem and progenitor cells is not only limited to organogenesis but also exists in postnatal life, where it is responsible for vessel wall homeostasis, remodeling and regeneration. It is believed that VW-SC/PC could be engaged in progression of vascular disorders and development of neointima. We would like to summarize current knowledge about mesenchymal and progenitor stem cell phenotype with special attention to distribution and biological properties of VW-SC/PC in biostructures of intima, media and adventitia niches. It is postulated that in the near future, niches for VW-SC/PC could be a good source of stem and progenitor cells, especially in the context of vessel tissue bioengineering as a new alternative to traditional revascularization therapies. PMID:24088542

Korta, Krzysztof; Kupczyk, Piotr; Skóra, Jan; Pupka, Artur; Zejler, Pawe?; Ho?ysz, Marcin; Gajda, Mariusz; Nowakowska, Beata; Bar?, Piotr; Dorobisz, Andrzej T; Dawiskiba, Tomasz; Szyber, Piotr; Bar, Julia

2013-09-18

405

Influence of wheat streak mosaic virus infection on phenylpropanoid metabolism and the accumulation of phenolics and lignin in wheat  

Microsoft Academic Search

Wheat plants infected with wheat streak mosaic virus were studied for their physiological response to infection. Previous histological data suggest that wheat streak mosaic virus-induced deposits of phenolic nature are present along the bundle sheath and mesophyll cell walls. In this study, we examined this phenomenon further by analysis of phenolic compounds and enzymes involved in their synthesis. In infected

S. A. Kofalvi; A. Nassuth

1995-01-01

406

Development and characterization of wheat lines with Sr37 for stem rust resistance derived from wild Timopheev's wheat  

Technology Transfer Automated Retrieval System (TEKTRAN)

The stem rust resistance gene Sr37, an effective gene against the newly emerged Ug99 races of Puccinia graminis f. sp. tritici in wheat, was originally transferred from wild Timopheev's wheat (Triticum timopheevii Zhuk, AAGG genomes) through a translocation between wheat chromosome 4B and T. timophe...

407

Association study of resistance to soil-borne wheat mosaic virus (SBWMV) in U.S. winter wheat  

Technology Transfer Automated Retrieval System (TEKTRAN)

Soil-borne wheat mosaic virus (SBWMV) is one of the most important winter wheat pathogens worldwide. To identify genes for resistance to the virus in U.S. winter wheat, association study was conducted using a selected panel of 205 elite experimental lines and cultivars from U.S. hard and soft winter...

408

Stem cell biology is population biology: differentiation of hematopoietic multipotent progenitors to common lymphoid and myeloid progenitors.  

PubMed

The hematopoietic stem cell (HSC) system is a demand control system, with the demand coming from the organism, since the products of the common myeloid and lymphoid progenitor (CMP, CLP respectively) cells are essential for activity and defense against disease. We show how ideas from population biology (combining population dynamics and evolutionary considerations) can illuminate the feedback control of the HSC system by the fully differentiated products, which has recently been verified experimentally. We develop models for the penultimate differentiation of HSC Multipotent Progenitors (MPPs) into CLP and CMP and introduce two concepts from population biology into stem cell biology. The first concept is the Multipotent Progenitor Commitment Response (MPCR) which is the probability that a multipotent progenitor cell follows a CLP route rather than a CMP route. The second concept is the link between the MPCR and a measure of Darwinian fitness associated with organismal performance and the levels of differentiated lymphoid and myeloid cells. We show that many MPCRs are consistent with homeostasis, but that they will lead to different dynamics of cells and signals following a wound or injury and thus have different consequences for Darwinian fitness. We show how coupling considerations of life history to dynamics of the HSC system and its products allows one to compute the selective pressures on cellular processes. We discuss ways that this framework can be used and extended. PMID:23327512

Mangel, Marc; Bonsall, Michael B

2013-01-17

409

Wheat storage proteins in transgenic rice endosperm.  

PubMed

Transgenic rice seed expressing wheat HMW glutenin subunit was characterized to study the effects of the wheat prolamin on the protein expression pattern and protein size distribution in the endosperm and the functional and rheological properties of the rice flour and dough. Significant differences were found in the protein expression pattern between the transgenic and wild type samples. Comparing the protein expression profiles of transgenic and nontransgenic plants, combined with proteomic-based studies, indicated increased protein disulfide isomerase (PDI) levels in the transgenic rice lines. The accurate molecular size of HMW-GS in rice endosperm was identified by MALDI-TOF-MS analysis. The expressed wheat HMW (subunit 1Dx5) GS showed a positive effect on the functional properties of rice dough by significantly increasing the size distribution of the polymeric protein fraction and modifying the dough mixing parameters. PMID:23802557

Oszvald, Mária; Balázs, Gábor; Pólya, Sára; Tömösközi, Sándor; Appels, Rudi; Békés, Ferenc; Tamás, László

2013-07-25

410

Genetic structure of Argentinean hexaploid wheat germplasm.  

PubMed

The identification of genetically homogeneous groups of individuals is an ancient issue in population genetics and in the case of crops like wheat, it can be valuable information for breeding programs, genetic mapping and germplasm resources. In this work we determined the genetic structure of a set of 102 Argentinean bread wheat (Triticum aestivum L.) elite cultivars using 38 biochemical and molecular markers (functional, closely linked to genes and neutral ones) distributed throughout 18 wheat chromosomes. Genetic relationships among these lines were examined using model-based clustering methods. In the analysis three subpopulations were identified which correspond largely to the origin of the germplasm used by the main breeding programs in Argentina. PMID:24130447

Vanzetti, Leonardo S; Yerkovich, Nadia; Chialvo, Eugenia; Lombardo, Lucio; Vaschetto, Luis; Helguera, Marcelo

2013-08-30

411

Drought tolerance in modern and wild wheat.  

PubMed

The genus Triticum includes bread (Triticum aestivum) and durum wheat (Triticum durum) and constitutes a major source for human food consumption. Drought is currently the leading threat on world's food supply, limiting crop yield, and is complicated since drought tolerance is a quantitative trait with a complex phenotype affected by the plant's developmental stage. Drought tolerance is crucial to stabilize and increase food production since domestication has limited the genetic diversity of crops including wild wheat, leading to cultivated species, adapted to artificial environments, and lost tolerance to drought stress. Improvement for drought tolerance can be achieved by the introduction of drought-grelated genes and QTLs to modern wheat cultivars. Therefore, identification of candidate molecules or loci involved in drought tolerance is necessary, which is undertaken by "omics" studies and QTL mapping. In this sense, wild counterparts of modern varieties, specifically wild emmer wheat (T. dicoccoides), which are highly tolerant to drought, hold a great potential. Prior to their introgression to modern wheat cultivars, drought related candidate genes are first characterized at the molecular level, and their function is confirmed via transgenic studies. After integration of the tolerance loci, specific environment targeted field trials are performed coupled with extensive analysis of morphological and physiological characteristics of developed cultivars, to assess their performance under drought conditions and their possible contributions to yield in certain regions. This paper focuses on recent advances on drought related gene/QTL identification, studies on drought related molecular pathways, and current efforts on improvement of wheat cultivars for drought tolerance. PMID:23766697

Budak, Hikmet; Kantar, Melda; Kurtoglu, Kuaybe Yucebilgili

2013-05-15

412

Progenitor-explosion Connection and Remnant Birth Masses for Neutrino-driven Supernovae of Iron-core Progenitors  

NASA Astrophysics Data System (ADS)

We perform hydrodynamic supernova (SN) simulations in spherical symmetry for over 100 single stars of solar metallicity to explore the progenitor-explosion and progenitor-remnant connections established by the neutrino-driven mechanism. We use an approximative treatment of neutrino transport and replace the high-density interior of the neutron star (NS) by an inner boundary condition based on an analytic proto-NS core-cooling model, whose free parameters are chosen such that explosion energy, nickel production, and energy release by the compact remnant of progenitors around 20 M ? are compatible with SN 1987A. Thus, we are able to simulate the accretion phase, initiation of the explosion, subsequent neutrino-driven wind phase for 15-20 s, and the further evolution of the blast wave for hours to days until fallback is completed. Our results challenge long-standing paradigms. We find that remnant mass, launch time, and properties of the explosion depend strongly on the stellar structure and exhibit large variability even in narrow intervals of the progenitors' zero-age main-sequence mass. While all progenitors with masses below ~15 M ? yield NSs, black hole (BH) as well as NS formation is possible for more massive stars, where partial loss of the hydrogen envelope leads to weak reverse shocks and weak fallback. Our NS baryonic masses of ~1.2-2.0 M ? and BH masses >6 M ? are compatible with a possible lack of low-mass BHs in the empirical distribution. Neutrino heating accounts for SN energies between some 1050 erg and ~2 × 1051 erg but can hardly explain more energetic explosions and nickel masses higher than 0.1-0.2 M ?. These seem to require an alternative SN mechanism.

Ugliano, Marcella; Janka, Hans-Thomas; Marek, Andreas; Arcones, Almudena

2012-09-01

413

Consumer liking of refined and whole wheat breads.  

PubMed

Preference for refined bread is often cited as a reason for the relatively low consumption of whole wheat bread; only a few studies, however, have examined consumer preferences between refined and whole wheat breads, and the results of these studies are inconclusive. Our objective was to determine if refined wheat bread is preferred to whole wheat bread. We hypothesized that people would prefer refined wheat bread. We conducted a taste test with 89 people. They rated their liking of 9 different breads chosen to represent several comparisons between equivalent refined and whole wheat breads. The participants also rated the intensity of 6-n-propylthiouracil (PROP) and completed a questionnaire about their bread preferences and purchasing habits. We classified the participants by their bread preference and their PROP taster status, and then examined the liking patterns of these subgroups. People preferred refined bread to whole wheat bread when both were made using equivalent ingredients and procedures. They liked the commercial samples of refined and whole wheat breads equally well. When people were classified by their bread preference, those who preferred refined bread liked the refined bread better in all comparisons. PROP nontasters liked all refined and whole wheat breads equally. Sensory preferences are a barrier to whole wheat bread consumption, but ingredient or processing modifications can improve liking of whole wheat bread to the level of refined bread. PMID:17995660

Bakke, A; Vickers, Z

2007-09-01

414

Improving wheat simulation capabilities in Australia from a cropping systems perspective III. The integrated wheat model (I_WHEAT)  

Microsoft Academic Search

Previous work has identified several short-comings in the ability of four spring wheat and one barley model to simulate crop processes and resource utilization. This can have important implications when such models are used within systems models where final soil water and nitrogen conditions of one crop define the starting conditions of the following crop. In an attempt to overcome

H. Meinke; G. L. Hammer; H. van Keulen; R. Rabbinge

1998-01-01

415

Storage products and transcriptional analysis of the endosperm of cultivated wheat and two wild wheat species  

Microsoft Academic Search

The starch and protein in wheat (Triticum aestivum L.) endosperm provide 20% of the calories eaten by humans and were heavily selected for during domestication. We examined\\u000a the main storage products and gene expression patterns that may embody compositional differences between two wild speciesAegilops crassa andAegilops tauschii and cultivated bread wheat. The storage product profiles differed significantly withT. aestivum accumulating

N. K. Uhlmann; D. M. Beckles

2010-01-01

416

Segregation of genetic markers among wheat doubled haploid lines derived from wheat x maize crosses  

Microsoft Academic Search

Wheat doubled haploid (DH) lines were produced from the F1 hybrid, Fukudo-komugi x Oligo Culm, through intergeneric crosses between wheat and maize. F2 plants and 203 DH lines were analyzed for the segregation of the eight genetic markers, namely, grain proteins, grain esterases, GA-insensitivity and glume traits. The segregation in the F2 plants fitted to the expected ratios. No deviation

Kazuhiro Suenaga; Kousuke Nakajima

1992-01-01

417

A spatial equilibrium analysis of trade policy reforms on the world wheat market  

Microsoft Academic Search

Since a few countries produce most of the world's wheat, and consumption is widespread across the world, wheat is one of the most commonly traded agricultural commodities. In recent years, the wheat market has been going through difficult phases as wheat prices are depressed. The fall in wheat prices is attributed to a supply glut and restrictive trade barriers. This

Antonio G. Gómez-Plana; Stephen Devadoss

2004-01-01

418

Utilization of alien genes to enhance Fusarium head blight resistance in wheat – A review  

Microsoft Academic Search

Fusarium head blight (FHB) is a destructive disease of wheat worldwide. Sources of resistance to FHB are limited in wheat. Search for novel sources of effective resistance to this disease has been an urgent need in wheat breeding. Fusarium head blight resistance has been identified in relatives of wheat. Alien chromatin carrying FHB resistance genes has been incorporated into wheat

X. Cai; P. D. Chen; S. S. Xu; R. E. Oliver; X. Chen

2005-01-01

419

Amino acid composition of spring wheats and losses of lysine during chapati baking  

Microsoft Academic Search

Forty-four spring wheat varieties representing 64 years of wheat cultivar releases were evaluated for amino acid composition. The concentration of several amino acids differed among the wheat varieties but amino acids did not significantly consistently among wheat varieties and growth conditions. Significant differences existed in amino acid score due to wheat varieties and crop years. The variations in amino acids

Faqir M. Anjum; Ijaz Ahmad; Masood S. Butt; M. A. Sheikh; Imran Pasha

2005-01-01

420

Wheat-dependent exercise-induced anaphylaxis sensitized with hydrolyzed wheat protein in soap.  

PubMed

Wheat-dependent exercise-induced anaphylaxis (WDEIA) is a specific form of wheat allergy typically induced by exercise after ingestion of wheat products. Wheat ?-5 gliadin is a major allergen associated with conventional WDEIA, and detection of serum immunoglobulin E (IgE) specific to recombinant ?-5 gliadin is a reliable method for its diagnosis. Recently, an increased incidence of a new subtype of WDEIA, which is likely to be sensitized via a percutaneous and/or rhinoconjunctival route to hydrolyzed wheat protein (HWP), has been observed. All of the patients with this new subtype had used the same brand of soap, which contained HWP. Approximately half of these patients developed contact allergy several months later and subsequently developed WDEIA. In each of these patients, contact allergy with soap exposure preceded food ingestion-induced reactions. Other patients directly developed generalized symptoms upon ingestion of wheat products. The predominant observed symptom of the new WDEIA subtype was angioedema of the eyelids; a number of patients developed anaphylaxis. This new subtype of WDEIA has little serum ?-5 gliadin-specific serum IgE. PMID:23093796

Chinuki, Yuko; Morita, Eishin

2012-10-25

421

Haematopoietic stem cells and early lymphoid progenitors occupy distinct bone marrow niches.  

PubMed

Although haematopoietic stem cells (HSCs) are commonly assumed to reside within a specialized microenvironment, or niche, most published experimental manipulations of the HSC niche have affected the function of diverse restricted progenitors. This raises the fundamental question of whether HSCs and restricted progenitors reside within distinct, specialized niches or whether they share a common niche. Here we assess the physiological sources of the chemokine CXCL12 for HSC and restricted progenitor maintenance. Cxcl12(DsRed) knock-in mice (DsRed-Express2 recombined into the Cxcl12 locus) showed that Cxcl12 was primarily expressed by perivascular stromal cells and, at lower levels, by endothelial cells, osteoblasts and some haematopoietic cells. Conditional deletion of Cxcl12 from haematopoietic cells or nestin-cre-expressing cells had little or no effect on HSCs or restricted progenitors. Deletion of Cxcl12 from endothelial cells depleted HSCs but not myeloerythroid or lymphoid progenitors. Deletion of Cxcl12 from perivascular stromal cells depleted HSCs and certain restricted progenitors and mobilized these cells into circulation. Deletion of Cxcl12 from osteoblasts depleted certain early lymphoid progenitors but not HSCs or myeloerythroid progenitors, and did not mobilize these cells into circulation. Different stem and progenitor cells thus reside in distinct cellular niches in bone marrow: HSCs occupy a perivascular niche and early lymphoid progenitors occupy an endosteal niche. PMID:23434755

Ding, Lei; Morrison, Sean J

2013-02-24

422

Haematopoietic stem cells and early lymphoid progenitors occupy distinct bone marrow niches  

PubMed Central

While haematopoietic stem cells (HSCs) are commonly assumed to reside within a specialized microenvironment, or niche1, most published experimental manipulations of the HSC niche have also impacted the function of diverse restricted progenitors. This raises the fundamental question of whether HSCs1 and restricted progenitors2,3 reside within distinct, specialized niches or whether they share a common niche. Here we assess the physiological sources of the chemokine, CXCL12, for HSC and restricted progenitor maintenance. Cxcl12DsRed knock-in mice showed that Cxcl12 was primarily expressed by perivascular stromal cells and at lower levels by endothelial cells, osteoblasts, and some haematopoietic cells. Conditional deletion of Cxcl12 from haematopoietic cells or Nestin-cre-expressing cells had little or no effect on HSCs or restricted progenitors. Deletion of Cxcl12 from endothelial cells depleted HSCs but not myeloerythroid or lymphoid progenitors. Deletion of Cxcl12 from perivascular stromal cells depleted HSCs and certain restricted progenitors and mobilized these cells into circulation. Deletion of Cxcl12 from osteoblasts depleted certain early lymphoid progenitors, but not HSCs or myeloerythroid progenitors and did not mobilize these cells into circulation. Different stem/progenitor cells thus occupy distinct cellular niches in bone marrow: HSCs in a perivascular niche and early lymphoid progenitors in an endosteal niche.

Ding, Lei; Morrison, Sean J.

2013-01-01

423

The Wintering of Uredomycelia of Wheat Rust.  

National Technical Information Service (NTIS)

Mycelia of the causative agent of stem rust in wheat are not killed by low air temperatures in the winter, except when there is no snow covering. With a snow covering of 17-20 cm, mycelia in the plants can pass the winter and create local, early sources o...

L. A. Smirnova Z. I. Bessneltsev Z. P. Shinkarev

1969-01-01

424

Wheat arabinoxylan structure provides insight into function  

Technology Transfer Automated Retrieval System (TEKTRAN)

Recent attention to dietary fiber in wheat (Triticum aestivum L.) has invigorated research in the non-starch carbohydrate arabinoxylan. Arabinoxylan (AX) molecules are comprised of a linear xylose backbone with arabinose substitutions along the backbone. These arabinose substituents can also carry a...

425

ANALYSIS OF THE WHEAT ENDOSPERM TRANSCRIPTOME  

Technology Transfer Automated Retrieval System (TEKTRAN)

Among the cereals, wheat is the most widely grown geographically and is part of the staple diet in much of the world. Understanding how the cereal endosperm develops and functions will help generate better tools to manipulate grain qualities important to end-users. We used a genomics approach to id...

426

Registration of Anton Hard White Winter Wheat  

Technology Transfer Automated Retrieval System (TEKTRAN)

‘Anton’ (Reg. No. CV PI 651043) hard white winter wheat (Triticum aestivum L.) was developed by the USDA-ARS and the Nebraska Agricultural Experiment Station and released in December, 2007. "Anton" was selected from the cross WA691213-27/N86L177//‘Platte’. Anton primarily was released for its lo...

427

DEVELOPMENT AND CHARACTERIZATION OF WAXY WINTER WHEATS  

Technology Transfer Automated Retrieval System (TEKTRAN)

Waxy grain crops produce endosperm starch lacking amylose and consisting only of amylopectin. Such starch is formed when mutations are present that eliminate the production, or function, of an enzyme known as the granule-bound starch synthase, (GBSS, or the “waxy protein”). Waxy winter wheat...

428

Controlling Soilborne Pathogens in Wheat Production Systems  

Technology Transfer Automated Retrieval System (TEKTRAN)

Pacific Northwest (PNW) wheat, barley, legume and canola varieties are susceptible to broad host-range soilborne pathogens that cause Rhizoctonia root rot and Pythium root rot. Controlling Rhizoctonia and Pythium will likely require multiple strategies. My laboratory focuses on three research areas:...

429

Molecular Weight Distribution of Wheat Proteins  

Microsoft Academic Search

Cereal Chem. 76(6):827-836 The molecular weight distribution (MWD) of wheat proteins is becoming recognized as the main determinant of physical dough prop- erties. Studies of high polymers have shown that properties such as tensile strength are related to a fraction of polymer with molecular weight above a critical value and the MWD of this fraction. Elongation to break is treated

M. Southan; F. MacRitchie

1999-01-01

430

Genetic analysis of plant height in wheat  

Microsoft Academic Search

Genetic studies of plant height were made of 8 wheats and the 28 crosses between them using the diallel method of analysis. The inheritance of plant height in a glasshouse-grown F1 diallel set in which vernalization and photoperiodic responses had been removed, indicated close to complete dominance in its expression. A similar F1 set of crosses in the field environment

G. M. Halloran

1974-01-01

431

Global Change -- What Future for Wheat?  

Technology Transfer Automated Retrieval System (TEKTRAN)

Grain yield and quality in cereals are often strongly influenced by flowering date. Ecophysiological models of bread wheat (Triticum aestivum L.) simulate the number of days to heading or anthesis by assuming that an intrinsic rate of development is modified by vernalization and photoperiodism. Cul...

432

Nutraceutical and functional scenario of wheat straw.  

PubMed

In the era of nutrition, much focus has been remunerated to functional and nutraceutical foodstuffs. The health endorsing potential of such provisions is attributed to affluent phytochemistry. These dynamic constituents have functional possessions that are imperative for cereal industry. The functional and nutraceutical significance of variety of foods is often accredited to their bioactive molecules. Numerous components have been considered but wheat straw and its diverse components are of prime consideration. In this comprehensive dissertation, efforts are directed to elaborate the functional and nutraceutical importance of wheat straw. Wheat straw is lignocellulosic materials including cellulose, hemicellulose and lignin. It hold various bioactive compounds such as policosanols, phytosterols, phenolics, and triterpenoids, having enormous nutraceutical properties like anti-allergenic, anti-artherogenic, anti-inflammatory, anti-microbial, antioxidant, anti-thrombotic, cardioprotective and vasodilatory effects, antiviral, and anticancer. These compounds are protecting against various ailments like hypercholesterolemia, intermittent claudication, benign prostatic hyperplasia and cardiovascular diseases. Additionally, wheat straw has demonstrated successfully, low cost, renewable, versatile, widely distributed, easily available source for the production of biogas, bioethanol, and biohydrogen in biorefineries to enhance the overall effectiveness of biomass consumption in protected and eco-friendly environment. Furthermore, its role in enhancing the quality and extending the shelf life of bakery products through reducing the progression of staling and retrogradation is limelight of the article. PMID:23216000

Pasha, Imran; Saeed, Farhan; Waqas, Khalid; Anjum, Faqir Muhammad; Arshad, Muhammad Umair

2013-01-01

433

?-Amylase inactivation during wheat starch hydrolysis process  

Microsoft Academic Search

The work reported here investigates the effects of operating conditions on enzymic hydrolysis of wheat starch. A commercial ?-amylase enzyme (Gemsize 4A, produced by Bacillus subtilis) was used for the hydrolysis experiments. The degree of hydrolysis (%) and ?-amylase activity (%) were investigated versus the process variables, pH, temperature, viscosity, amount of enzyme preparation added, impeller speed, amount of hydrolysate

Belma Özbek; Semra Yüceer

2001-01-01

434

Hydrogen as a test of type Ia supernova progenitor models  

SciTech Connect

If type Ia supernovae are produced by the explosion of a white dwarf accreting matter from a hydrogen-rich companion, the material stripped and ablated from the companion during the explosion will contaminate the supernova spectrum with hydrogen. The amount of material stripped and ablated from the companion is calculated, showing that a hydrogen mass fraction of at least X(H) greater than 0.01 should exist in type Ia supernovae if their progenitors are cataclysmic variable-like systems. This amount of hydrogen is barely consistent with current upper limits, but the inhomogeneous distribution of the hydrogenin the ejecta must be taken into account before detailed comparisons can be made. White dwarfs accreting from Roche lobe-filling red giants can probably be ruled out as SN Ia progenitors because they contaminate the spectrum with too much hydrogen. 11 refs.

Applegate, J.H.; Terman, J.L.

1989-05-01

435

Progenitors of type Ia supernovae in elliptical galaxies  

NASA Astrophysics Data System (ADS)

Although there is a nearly universal agreement that type Ia supernovae are associated with the thermonuclear disruption of a CO white dwarf, the exact nature of their progenitors is still unknown. The single degenerate scenario envisages a white dwarf accreting matter from a non-degenerate companion in a binary system. Nuclear energy of the accreted matter is released in the form of electromagnetic radiation or gives rise to numerous classical nova explosions prior to the supernova event. We show that combined X-ray output of supernova progenitors and statistics of classical novae predicted in the single degenerate scenario are inconsistent with X-ray and optical observations of nearby early type galaxies and galaxy bulges. White dwarfs accreting from a donor star in a binary system and detonating at the Chandrasekhar mass limit can account for no more than ~5% of type Ia supernovae observed in old stellar populations.

Gilfanov, M.; Bogdán, Á.

2011-09-01

436

Progenitors Of Type Ia Supernovae In Early Type Galaxies  

NASA Astrophysics Data System (ADS)

Although there is a nearly universal agreement that SNeIa are associated with the thermonuclear disruption of a CO white dwarf, the exact nature of their progenitors is still unknown. The single degenerate scenario envisages a white dwarf accreting matter from a non-degenerate companion in a binary system. Gravitational and nuclear energy of the accreted matter is released in the form of electromagnetic radiation and/or kinetic power of Classical Novae explosions *prior* to the Supernova event. We show that combined X-ray output of SNIa progenitors and statistics of Classical Novae predicted in the single degenerate scenario are inconsistent with X-ray and optical observations of nearby early type galaxies and galaxy bulges. White dwarfs accreting from a donor star in a binary system and detonating at the Chandrasekhar mass limit can account for no more than 5% of type Ia supernovae observed in old stellar populations.

Gilfanov, Marat; Bogdan, A.

2011-09-01

437

The Mammary Gland Microenvironment Directs Progenitor Cell Fate In Vivo  

PubMed Central

The mammary gland is a unique organ that continually undergoes postnatal developmental changes. In mice, the mammary gland is formed via signals from terminal end buds, which direct ductal growth and elongation. Intriguingly, it is likely that the entire cellular repertoire of the mammary gland is formed from a single antecedent cell. Furthermore, in order to produce progeny of varied lineages (e.g., luminal and myoepithelial cells), signals from the local tissue microenvironment influence mammary stem/progenitor cell fate. Data have shown that cells from the mammary gland microenvironment reprogram adult somatic cells from other organs (testes, nerve) into cells that produce milk and express mammary epithelial cell proteins. Similar results were found for human tumorigenic epithelial carcinoma cells. Presently, it is unclear how the deterministic power of the mammary gland microenvironment controls epithelial cell fate. Regardless, signals generated by the microenvironment have a profound influence on progenitor cell differentiation in vivo.

Bussard, Karen M.; Smith, Gilbert H.

2011-01-01

438

Is Black-Hole Ringdown a Memory of Its Progenitor?  

NASA Astrophysics Data System (ADS)

We perform an extensive numerical study of coalescing black-hole binaries to understand the gravitational-wave spectrum of quasinormal modes excited in the merged black hole. Remarkably, we find that the masses and spins of the progenitor are clearly encoded in the mode spectrum of the ringdown signal. Some of the mode amplitudes carry the signature of the binary’s mass ratio, while others depend critically on the spins. Simulations of precessing binaries suggest that our results carry over to generic systems. Using Bayesian inference, we demonstrate that it is possible to accurately measure the mass ratio and a proper combination of spins even when the binary is itself invisible to a detector. Using a mapping of the binary masses and spins to the final black-hole spin allows us to further extract the spin components of the progenitor. Our results could have tremendous implications for gravitational astronomy by facilitating novel tests of general relativity using merging black holes.

Kamaretsos, Ioannis; Hannam, Mark; Sathyaprakash, B. S.

2012-10-01

439

Close Binaries, Rotation, and Instabilities in Supernova Progenitors  

NASA Astrophysics Data System (ADS)

Statistics of various types of supernovae suggest that RLOF in close binaries rather than single-star mass loss dominates the removal of the H envelope for massive stars across a wide range of masses, and that very massive stars that shed their H envelopes via stellar winds to make WR stars are not the common progenitors of most stripped-envelope (Types Ic, Ib, and IIb) supernovae. Also, RLOF can have profound effects on the mass gainer in these binary systems, including rapid rotation and instability. The eclipsing binary RY Scuti is a massive binary that is caught in this brief RLOF phase. I will discuss recent results concerning the kinematics of RY Scuti's toroidal nebula that provide interesting clues about the mass loss, mass transfer, and instability in this type of system. I will also discuss corresponding implications for the progenitor systems of stripped-envelope supernovae.

Smith, N.

2012-12-01

440

Imparting regenerative capacity to limbs by progenitor cell transplantation.  

PubMed

The frog Xenopus can normally regenerate its limbs at early developmental stages but loses the ability during metamorphosis. This behavior provides a potential gain-of-function model for measures that can enhance limb regeneration. Here, we show that frog limbs can be caused to form multidigit regenerates after receiving transplants of larval limb progenitor cells. It is necessary to activate Wnt/?-catenin signaling in the cells and to add Sonic hedgehog, FGF10, and thymosin ?4. These factors promote survival and growth of the grafted cells and also provide pattern information. The eventual regenerates are not composed solely of donor tissue; the host cells also make a substantial contribution despite their lack of regeneration competence. Cells from adult frog legs or from regenerating tadpole tails do not promote limb regeneration, demonstrating the necessity for limb progenitor cells. These findings have obvious implications for the development of a technology to promote limb regeneration in mammals. PMID:23273877

Lin, Gufa; Chen, Ying; Slack, Jonathan M W

2012-12-27

441

The Population of Helium-merger Progenitors: Observational Predictions  

NASA Astrophysics Data System (ADS)

The helium-merger gamma-ray burst (GRB) progenitor is produced by the rapid accretion onto a compact remnant (neutron star or black hole) when it undergoes a common envelope inspiral with its companion's helium core. This merger phase produces a very distinct environment around these outbursts and recent observations suggest that, in some cases, we are detecting the signatures of the past merger in the GRB afterglow. These observations allow us, for the first time, to study the specific features of the helium-merger progenitor. In this paper, we couple population synthesis calculations to our current understanding of GRB engines and common envelope evolution to make observational predictions for the helium-merger GRB population. Many mergers do not produce GRB outbursts and we discuss the implications of these mergers with the broader population of astrophysical transients.

Fryer, Chris L.; Belczynski, Krzysztof; Berger, Edo; Thöne, Christina; Ellinger, Carola; Bulik, Tomasz

2013-02-01

442

Is black-hole ringdown a memory of its progenitor?  

PubMed

We perform an extensive numerical study of coalescing black-hole binaries to understand the gravitational-wave spectrum of quasinormal modes excited in the merged black hole. Remarkably, we find that the masses and spins of the progenitor are clearly encoded in the mode spectrum of the ringdown signal. Some of the mode amplitudes carry the signature of the binary's mass ratio, while others depend critically on the spins. Simulations of precessing binaries suggest that our results carry over to generic systems. Using Bayesian inference, we demonstrate that it is possible to accurately measure the mass ratio and a proper combination of spins even