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1

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

2

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

3

Variation in dehydration tolerance, ABA sensitivity and related gene expression patterns in D-genome progenitor and synthetic hexaploid wheat lines.  

PubMed

The wild wheat Aegilops tauschii Coss. has extensive natural variation available for breeding of common wheat. Drought stress tolerance is closely related to abscisic acid (ABA) sensitivity. In this study, 17 synthetic hexaploid wheat lines, produced by crossing the tetraploid wheat cultivar Langdon with 17 accessions of Ae. tauschii, were used for comparative analysis of natural variation in drought tolerance and ABA sensitivity. Ae. tauschii showed wide natural variation, with weak association between the traits. Drought-sensitive accessions of Ae. tauschii exhibited significantly less ABA sensitivity. D-genome variations observed at the diploid genome level were not necessarily reflected in synthetic wheats. However, synthetic wheats derived from the parental Ae. tauschii accessions with high drought tolerance were significantly more tolerant to drought stress than those from drought-sensitive accessions. Moreover, synthetic wheats with high drought tolerance showed significantly higher ABA sensitivity than drought-sensitive synthetic lines. In the hexaploid genetic background, therefore, weak association of ABA sensitivity with drought tolerance was observed. To study differences in gene expression patterns between stress-tolerant and -sensitive lines, levels of two Cor/Lea and three transcription factor gene transcripts were compared. The more tolerant accession of Ae. tauschii tended to accumulate more abundant transcripts of the examined genes than the sensitive accession under stress conditions. The expression patterns in the synthetic wheats seemed to be additive for parental lines exposed to drought and ABA treatments. However, the transcript levels of transcription factor genes in the synthetic wheats did not necessarily correspond to the postulated levels based on expression in parental lines. Allopolyploidization altered the expression levels of the stress-responsive genes in synthetic wheats. PMID:19582226

Kurahashi, Yumeto; Terashima, Akihiro; Takumi, Shigeo

2009-06-01

4

Construction and characterisation of a large DNA insert library from the D genome of wheat  

Microsoft Academic Search

A large DNA fragment library consisting of 144?000 clones with an average insert size of 119 kb was constructed from nuclear\\u000a DNA isolated from root and leaf tissue from Triticum tauschii (syn. Aegilops tauschii), the D-genome progenitor of wheat. The library was made in a binary vector that had previously been shown to stably maintain\\u000a large inserts of foreign DNA

O. Moullet; H.-B. Zhang; E. S. Lagudah

1999-01-01

5

Retention of D genome chromosomes in pentaploid wheat crosses  

PubMed Central

The transfer of genes between Triticum aestivum (hexaploid bread wheat) and T. turgidum (tetraploid durum wheat) holds considerable potential for genetic improvement of both these closely related species. Five different T. aestivum/T. turgidum ssp. durum crosses were investigated using Diversity Arrays Technology (DArT) markers to determine the inheritance of parental A, B and D genome material in subsequent generations derived from these crosses. The proportions of A, B and D chromosomal segments inherited from the hexaploid parent were found to vary significantly among individual crosses. F2 populations retained widely varying quantities of D genome material, ranging from 99% to none. The relative inheritance of bread wheat and durum alleles in the A and B genomes of derived lines also varied among the crosses. Within any one cross, progeny without D chromosomes in general had significantly more A and B genome durum alleles than lines retaining D chromosomes. The ability to select for and manipulate this non-random segregation in bread wheat/durum crosses will assist in efficient backcrossing of selected characters into the recurrent durum or hexaploid genotype of choice. This study illustrates the utility of DArT markers in the study of inter-specific crosses to commercial crop species.

Martin, A; Simpfendorfer, S; Hare, R A; Eberhard, F S; Sutherland, M W

2011-01-01

6

Identification of quantitative trait loci for abscisic acid responsiveness in the D-genome of hexaploid wheat.  

PubMed

In crop species such as wheat, abiotic stresses and preharvest sprouting reduce grain yield and quality. The plant hormone abscisic acid (ABA) plays important roles in abiotic stress tolerance and seed dormancy. In previous studies, we evaluated ABA responsiveness of 67 Aegilops tauschii accessions and their synthetic hexaploid wheat lines, finding wide variation that was due to the D-genome. In this study, quantitative trait locus (QTL) analysis was performed using an F2 population derived from crosses of highly ABA-responsive and less-responsive synthetic wheat lines. A significant QTL was detected on chromosome 6D, in a similar location to that reported for ABA responsiveness using recombinant inbred lines derived from common wheat cultivars Mironovskaya 808 and Chinese Spring. A comparative map and physiological and expression analyses of the 6D QTL suggested that this locus involved in line differences among wheat synthetics is different from that involved in cultivar differences in common wheat. The common wheat 6D QTL was found to affect seed dormancy and the regulation of cold-responsive/late embryogenesis abundant genes during dehydration. However, in synthetic wheat, we failed to detect any association of ABA responsiveness with abiotic stress tolerance or seed dormancy, at least under our experimental conditions. Development of near-isogenic lines will be important for functional analyses of the synthetic wheat 6D QTL. PMID:24877675

Iehisa, Julio C M; Matsuura, Takakazu; Mori, Izumi C; Yokota, Hirokazu; Kobayashi, Fuminori; Takumi, Shigeo

2014-06-15

7

Genetic mapping within the wheat D genome reveals QTL for germination, seed vigour and longevity, and early seedling growth  

Microsoft Academic Search

Quantitative trait loci (QTL) controlling germination, seed vigour and longevity, and early seedling growth were identified\\u000a using a set of common wheat lines carrying known D genome introgression segments. Seed germination (capacity, timing, rate\\u000a and synchronicity) was characterized by a standard germination test, based either on the 1 mm root protrusion (germination\\u000a sensu stricto) or the development of normal seedlings. To

S. Landjeva; U. Lohwasser; A. Börner

2010-01-01

8

Phylogenetic relationships of Triticum and Aegilops and evidence for the origin of the A, B, and D genomes of common wheat (Triticum aestivum).  

PubMed

Common wheat (Triticum aestivum) has for decades been a textbook example of the evolution of a major crop species by allopolyploidization. Using a sophisticated extension of the PCR technique, we have successfully isolated two single-copy nuclear genes, DMC1 and EF-G, from each of the three genomes found in hexaploid wheat (BA(u)D) and from the two genomes of the tetraploid progenitor Triticum turgidum (BA(u)). By subjecting these sequences to phylogenetic analysis together with sequences from representatives of all the diploid Triticeae genera we are able for the first time to provide simultaneous and strongly supported evidence for the D genome being derived from Aegilops tauschii, the A(u) genome being derived from Triticum urartu, and the hitherto enigmatic B genome being derived from Aegilops speltoides. Previous problems of identifying the B genome donor may be associated with a higher diversification rate of the B genome compared to the A(u) genome in the polyploid wheats. The phylogenetic hypothesis further suggests that neither Triticum, Aegilops, nor Triticum plus Aegilops are monophyletic. PMID:16504543

Petersen, Gitte; Seberg, Ole; Yde, Merete; Berthelsen, Kasper

2006-04-01

9

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

10

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

2013-11-01

11

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

12

Highly recombinogenic regions at seed storage protein loci on chromosome 1DS of Aegilops tauschii, the D-genome donor of wheat.  

PubMed Central

A detailed RFLP map was constructed of the distal end of the short arm of chromosome 1D of Aegilops tauschii, the diploid D-genome donor species of hexaploid wheat. Ae. tauschii was used to overcome some of the limitations commonly associated with molecular studies of wheat such as low levels of DNA polymorphism. Detection of multiple loci by most RFLP probes suggests that gene duplication events have occurred throughout this chromosomal region. Large DNA fragments isolated from a BAC library of Ae. tauschii were used to determine the relationship between physical and genetic distance at seed storage protein loci located at the distal end of chromosome 1DS. Highly recombinogenic regions were identified where the ratio of physical to genetic distance was estimated to be <20 kb/cM. These results are discussed in relation to the genome-wide estimate of the relationship between physical and genetic distance.

Spielmeyer, W; Moullet, O; Laroche, A; Lagudah, E S

2000-01-01

13

Durum wheat as a candidate for the unknown female progenitor of bread wheat: an empirical study with a highly fertile F1 hybrid with Aegilops tauschii Coss.  

PubMed

Hexaploid bread wheat was derived from a hybrid cross between a cultivated form of tetraploid Triticum wheat (female progenitor) and a wild diploid species, Aegilops tauschii Coss. (male progenitor). This cross produced a fertile triploid F1 hybrid that set hexaploid seeds. The identity of the female progenitor is unknown, but various cultivated tetraploid Triticum wheats exist today. Genetic and archaeological evidence suggests that durum wheat ( T. turgidum ssp. durum) may be the female progenitor. In previous studies, however, F1 hybrids of durum wheat crossed with Ae. tauschii consistently had low levels of fertility. To establish an empirical basis for the theory of durum wheat being the female progenitor of bread wheat, we crossed a durum wheat cultivar that carries a gene for meiotic restitution with a line of Ae. tauschii. F1 hybrids were produced without using embryo rescue techniques. These triploid F1 hybrids were highly fertile and spontaneously set hexaploid F2 seeds at the average selfed seedset rate of 51.5%. To the best of our knowledge, this is the first example of the production of highly fertile F1 hybrids between durum wheat and Ae. tauschii. The F1 and F2 hybrids are both similar morphologically to bread wheat and have vigorous growth habits. Cytological analyses of F1 male gametogenesis showed that meiotic restitution is responsible for the high fertility of the triploid F1 hybrids. The implications of these findings for the origin of bread wheat are discussed. PMID:15448900

Matsuoka, Yoshihiro; Nasuda, Shuhei

2004-11-01

14

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

15

Independent wheat B and G genome origins in outcrossing Aegilops progenitor haplotypes.  

PubMed

The origin of modern wheats involved alloploidization among related genomes. To determine if Aegilops speltoides was the donor of the B and G genomes in AABB and AAGG tetraploids, we used a 3-tiered approach. Using 70 amplified fragment length polymorphism (AFLP) loci, we sampled molecular diversity among 480 wheat lines from their natural habitats encompassing all S genome Aegilops, the putative progenitors of wheat B and G genomes. Fifty-nine Aegilops representatives for S genome diversity were compared at 375 AFLP loci with diploid, tetraploid, and 11 nulli-tetrasomic Triticum aestivum wheat lines. B genome-specific markers allowed pinning the origin of the B genome to S chromosomes of A. speltoides, while excluding other lineages. The outbreeding nature of A. speltoides influences its molecular diversity and bears upon inferences of B and G genome origins. Haplotypes at nuclear and chloroplast loci ACC1, G6PDH, GPT, PGK1, Q, VRN1, and ndhF for approximately 70 Aegilops and Triticum lines (0.73 Mb sequenced) reveal both B and G genomes of polyploid wheats as unique samples of A. speltoides haplotype diversity. These have been sequestered by the AABB Triticum dicoccoides and AAGG Triticum araraticum lineages during their independent origins. PMID:17053048

Kilian, B; Ozkan, H; Deusch, O; Effgen, S; Brandolini, A; Kohl, J; Martin, W; Salamini, F

2007-01-01

16

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

17

Discovery of high-confidence single nucleotide polymorphisms from large-scale de novo analysis of leaf transcripts of Aegilops tauschii, a wild wheat progenitor.  

PubMed

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. PMID:23125207

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

2012-12-01

18

Genetic Fingerprinting of Wheat and Its Progenitors by Mitochondrial Gene orf256  

PubMed Central

orf256 is a wheat mitochondrial gene associated with cytoplasmic male sterility (CMS) that has different organization in various species. This study exploited the orf256 gene as a mitochondrial DNA marker to study the genetic fingerprint of Triticum and Aegilops species. PCR followed by sequencing of common parts of the orf256 gene were employed to determine the fingerprint and molecular evolution of Triticum and Aegilops species. Although many primer pairs were used, two pairs of orf256 specific primers (5:-94/C: 482, 5:253/C: 482), amplified DNA fragments of 576 bp and 230 bp respectively in all species were tested. A common 500 bp of nine species of Triticum and Aegilops were aligned and showed consistent results with that obtained from other similar chloroplast or nuclear genes. Base alignment showed that there were various numbers of base substitutions in all species compared to S. cereal (Sc) (the outgroup species). Phylogenetic relationship revealed similar locations and proximity on phylogenetic trees established using plastid and nuclear genes. The results of this study open a good route to use unknown function genes of mitochondria in studying the molecular relationships and evolution of wheat and complex plant genomes.

El-Shehawi, Ahmed M.; Fahmi, Abdelmeguid I.; Sayed, Samy M.; Elseehy, Mona M.

2012-01-01

19

Comparison of Starch-Branching Enzyme Genes Reveals Evolutionary Relationships Among Isoforms. Characterization of a Gene for Starch-Branching Enzyme IIa from the Wheat D Genome Donor Aegilops tauschii1  

PubMed Central

Genes and cDNAs for starch-branching enzyme II (SBEII) have been isolated from libraries constructed from Aegilops tauschii and wheat (Triticum aestivum) endosperm, respectively. One class of genes has been termed wSBEII-DA1 and encodes the N terminus reported for an SBEII from wheat endosperm. On the basis of phylogenetic comparisons with other branching enzyme sequences, wSBEII-DA1 is considered to be a member of the SBEIIa class. The wSBEII-DA1 gene consists of 22 exons with exons 4 to 21 being identical in length to the maize (Zea mays) SBEIIb gene, and the gene is located in the proximal region of the long arm of chromosome 2 at a locus designated sbe2a. RNA encoding SBEIIa can be detected in the endosperm from 6 d after flowering and is at its maximum level from 15 to 18 d after anthesis. Use of antibodies specific for SBEIIa demonstrated that this protein was present in both the soluble and granule bound fractions in developing wheat endosperm. We also report a cDNA sequence for SBEIIa that could arise by variant transcription/splicing. A second gene, termed wSBEII-DB1, was isolated and encodes an SBEII, which shows greater sequence identity with SBEIIb-type sequences than with SBEIIa-type sequences. Comparisons of SBEII gene structures among wheat, maize, and Arabidopsis indicate the lineage of the SBEII genes.

Rahman, Sadequr; Regina, Ahmed; Li, Zhongyi; Mukai, Yasuhiko; Yamamoto, Maki; Kosar-Hashemi, Behjat; Abrahams, Sharon; Morell, Matthew K.

2001-01-01

20

HMW and LMW glutenin alleles among putative tetraploid and hexaploid European spelt wheat (Triticum spelta L.) progenitors.  

PubMed

The allelic compositions of high- and low-molecular-weight subunits of glutenins (HMW-GS and LMW-GS) among European spelt ( Triticum spelta L.) and related hexaploid and tetraploid Triticum species were investigated by one- and two-dimensional polyacrylamide-gel electrophoresis (PAGE) and capillary electrophoresis (CE). A total of seven novel glutenin alleles (designated A1a*, B1d*, B1g*, B1f*, B1j*, D1a* at Glu-1 and A3h at the Glu-3 loci, respectively) in European spelt wheat were detected by SDS-PAGE, which were confirmed further by employing A-PAGE and CE methods. Particularly, two HMW-GS alleles, Glu-B1d* coding the subunits 6.1 and 22.1, and Glu-B1f* coding the subunits 13 and 22*, were found to occur in European spelt with frequencies of 32.34% and 5.11%, respectively. These two alleles were present in cultivated emmer (Triticum dicoccum), but they were not observed in bread wheat (Triticum aestivum L.). The allele Glu-B1g* coding for 13* and 19* subunits found in spelt wheat was also detected in club wheat (Triticum compactum L.). Additionally, two alleles coding for LMW-GS, Glu-A3h and Glu-B3d, occurred with high frequencies in spelt, club and cultivated emmer wheat, whereas these were not found or present with very low frequencies in bread wheat. Our results strongly support the secondary origin hypothesis, namely European spelt wheat originated from hybridization between cultivated emmer and club wheat. This is also confirmed experimentally by the artificial synthesis of spelt through crossing between old European emmer wheat, T. dicoccum and club wheat, T. compactum. PMID:13679994

Yan, Y; Hsam, S L K; Yu, J Z; Jiang, Y; Ohtsuka, I; Zeller, F J

2003-11-01

21

Recent emergence of the wheat Lr34 multi-pathogen resistance: insights from haplotype analysis in wheat, rice, sorghum and Aegilops tauschii.  

PubMed

Spontaneous sequence changes and the selection of beneficial mutations are driving forces of gene diversification and key factors of evolution. In highly dynamic co-evolutionary processes such as plant-pathogen interactions, the plant's ability to rapidly adapt to newly emerging pathogens is paramount. The hexaploid wheat gene Lr34, which encodes an ATP-binding cassette (ABC) transporter, confers durable field resistance against four fungal diseases. Despite its extensive use in breeding and agriculture, no increase in virulence towards Lr34 has been described over the last century. The wheat genepool contains two predominant Lr34 alleles of which only one confers disease resistance. The two alleles, located on chromosome 7DS, differ by only two exon-polymorphisms. Putatively functional homoeologs and orthologs of Lr34 are found on the B-genome of wheat and in rice and sorghum, but not in maize, barley and Brachypodium. In this study we present a detailed haplotype analysis of homoeologous and orthologous Lr34 genes in genetically and geographically diverse selections of wheat, rice and sorghum accessions. We found that the resistant Lr34 haplotype is unique to the wheat D-genome and is not found in the B-genome of wheat or in rice and sorghum. Furthermore, we only found the susceptible Lr34 allele in a set of 252 Ae. tauschii genotypes, the progenitor of the wheat D-genome. These data provide compelling evidence that the Lr34 multi-pathogen resistance is the result of recent gene diversification occurring after the formation of hexaploid wheat about 8,000 years ago. PMID:23117720

Krattinger, Simon G; Jordan, David R; Mace, Emma S; Raghavan, Chitra; Luo, Ming-Cheng; Keller, Beat; Lagudah, Evans S

2013-03-01

22

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

PubMed

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 V(329)-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. PMID:22042872

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

2011-11-15

23

A draft physical map of a D-genome cotton species (Gossypium raimondii)  

PubMed Central

Background Genetically anchored physical maps of large eukaryotic genomes have proven useful both for their intrinsic merit and as an adjunct to genome sequencing. Cultivated tetraploid cottons, Gossypium hirsutum and G. barbadense, share a common ancestor formed by a merger of the A and D genomes about 1-2 million years ago. Toward the long-term goal of characterizing the spectrum of diversity among cotton genomes, the worldwide cotton community has prioritized the D genome progenitor Gossypium raimondii for complete sequencing. Results A whole genome physical map of G. raimondii, the putative D genome ancestral species of tetraploid cottons was assembled, integrating genetically-anchored overgo hybridization probes, agarose based fingerprints and 'high information content fingerprinting' (HICF). A total of 13,662 BAC-end sequences and 2,828 DNA probes were used in genetically anchoring 1585 contigs to a cotton consensus genetic map, and 370 and 438 contigs, respectively to Arabidopsis thaliana (AT) and Vitis vinifera (VV) whole genome sequences. Conclusion Several lines of evidence suggest that the G. raimondii genome is comprised of two qualitatively different components. Much of the gene rich component is aligned to the Arabidopsis and Vitis vinifera genomes and shows promise for utilizing translational genomic approaches in understanding this important genome and its resident genes. The integrated genetic-physical map is of value both in assembling and validating a planned reference sequence.

2010-01-01

24

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

25

Map-based analysis of the tenacious glume gene Tg-B1 of wild emmer and its role in wheat domestication.  

PubMed

The domestication of wheat was instrumental in spawning the civilization of humankind, and it occurred through genetic mutations that gave rise to types with non-fragile rachises, soft glumes, and free-threshing seed. Wild emmer (Triticum turgidum ssp. dicoccoides), the tetraploid AB-genome progenitor of domesticated wheat has genes that confer tenacious glumes (Tg) that underwent genetic mutations to give rise to free-threshing wheat. Here, we evaluated disomic substitution lines involving chromosomes 2A and 2B of wild emmer accessions substituted for homologous chromosomes in tetraploid and hexaploid backgrounds. The results suggested that both chromosomes 2A and 2B of wild emmer possess genes that inhibit threshability. A population of recombinant inbred lines derived from the tetraploid durum wheat variety Langdon crossed with a Langdon - T. turgidum ssp. dicoccoides accession PI 481521 chromosome 2B disomic substitution line was used to develop a genetic linkage map of 2B, evaluate the genetics of threshability, and map the gene derived from PI 481521 that inhibited threshability. A 2BS linkage map comprised of 58 markers was developed, and markers delineated the gene to a 2.3 cM interval. Comparative analysis with maps containing the tenacious glume gene Tg-D1 on chromosome arm 2 DS from Aegilops tauschii, the D genome progenitor of hexaploid wheat, revealed that the gene inhibiting threshability in wild emmer was homoeologous to Tg-D1 and therefore designated Tg-B1. Comparative analysis with rice and Brachypodium distachyon indicated a high level of divergence and poorly conserved colinearity, particularly near the Tg-B1 locus. These results provide a foundation for further studies involving Tg-B1, which, together with Tg-D1, had profound influences on wheat domestication. PMID:24657062

Faris, Justin D; Zhang, Zengcui; Chao, Shiaoman

2014-06-01

26

Identification of transposons, retroelements, and a gene family predominantly expressed in floral tissues in chromosome 3DS of the hexaploid wheat progenitor Aegilops tauschii.  

PubMed

A multigene family expressed during early floral development was identified on the short arm of wheat chromosome 3D in the region of the Ph2 locus, a locus controlling homoeologous chromosome pairing in allohexaploid wheat. Physical, genetic and molecular characterisation of the Wheat Meiosis 1 (WM1) gene family identified seven members that localised within a region of 173-kb. WM1 gene family members were sequenced and they encode mainly type Ia plasma membrane-anchored leucine rich repeat-like receptor proteins. In situ expression profiling suggests the gene family is predominantly expressed in floral tissue. In addition to the WM1 gene family, a number of other genes, gene fragments and pseudogenes were identified. It has been predicted that there is approximately one gene every 19-kb and that this region of the wheat genome contains 23 repetitive elements including BARE-1 and Wis2-1 like sequences. Nearly 50% of the repetitive elements identified were similar to known transposons from the CACTA superfamily. Ty1-copia, Ty3-gypsy and Athila LTR retroelements were also prevalent within the region. The WM1 gene cluster is present on 3DS and on barley 3HS but missing from the A and B genomes of hexaploid wheat. This suggests either recent generation of the cluster or specific deletion of the cluster during wheat polyploidisation. The evolutionary significance of the cluster, its possible roles in disease response or floral and early meiotic development and its location at or near the Ph2 locus are discussed. PMID:16534632

Whitford, Ryan; Baumann, Ute; Sutton, Tim; Gumaelius, Luke; Wolters, Petra; Tingey, Scott; Able, Jason A; Langridge, Peter

2007-01-01

27

mRNA and Small RNA Transcriptomes Reveal Insights into Dynamic Homoeolog Regulation of Allopolyploid Heterosis in Nascent Hexaploid Wheat[W][OPEN  

PubMed Central

Nascent allohexaploid wheat may represent the initial genetic state of common wheat (Triticum aestivum), which arose as a hybrid between Triticum turgidum (AABB) and Aegilops tauschii (DD) and by chromosome doubling and outcompeted its parents in growth vigor and adaptability. To better understand the molecular basis for this success, we performed mRNA and small RNA transcriptome analyses in nascent allohexaploid wheat and its following generations, their progenitors, and the natural allohexaploid cultivar Chinese Spring, with the assistance of recently published A and D genome sequences. We found that nonadditively expressed protein-coding genes were rare but relevant to growth vigor. Moreover, a high proportion of protein-coding genes exhibited parental expression level dominance, with genes for which the total homoeolog expression level in the progeny was similar to that in T. turgidum potentially participating in development and those with similar expression to that in Ae. tauschii involved in adaptation. In addition, a high proportion of microRNAs showed nonadditive expression upon polyploidization, potentially leading to differential expression of important target genes. Furthermore, increased small interfering RNA density was observed for transposable element–associated D homoeologs in the allohexaploid progeny, which may account for biased repression of D homoeologs. Together, our data provide insights into small RNA–mediated dynamic homoeolog regulation mechanisms that may contribute to heterosis in nascent hexaploid wheat.

Li, Aili; Liu, Dengcai; Wu, Jun; Zhao, Xubo; Hao, Ming; Geng, Shuaifeng; Yan, Jun; Jiang, Xiaoxue; Zhang, Lianquan; Wu, Junyan; Yin, Lingjie; Zhang, Rongzhi; Wu, Liang; Zheng, Youliang; Mao, Long

2014-01-01

28

Phylogeny and genetic diversity of D genome species of Aegilops and Triticum (Triticeae, Poaceae) from Iran based on microsatellites, ITS, and trn LF  

Microsoft Academic Search

Cereal species of the grass tribe Triticeae are economically important and provide staple food for large parts of the human\\u000a population. The Fertile Crescent of Southwest Asia harbors high genetic and morphological diversity of these species. In this\\u000a study, we analyzed genetic diversity and phylogenetic relationships among D genome-bearing species of the wheat relatives of the genus Aegilops from Iran

Firouzeh Bordbar; Mohammad Reza Rahiminejad; Hojjatollah Saeidi; Frank R. Blattner

2011-01-01

29

Evaluation of synthetic hexaploid wheats (derivative of durum wheats and Aegilops tauschii accessions) for studying genetic diversity using randomly amplified polymorphic DNA (RAPD) markers.  

PubMed

Synthetic hexaploid (SH) wheat derived from crossing tetraploid durum wheat and diploid Aegilops tauschii provide germplasm for wheat improvement as the conventional wheat varieties possess very low genetic diversity. This study aims to identify diverse SH lines which can be used in breeding programs for transferring the desired traits into bread wheat. The study was conducted on 24 SH lines using 10 pairs of randomly amplified polymorphic DNA (RAPD) markers. Application of RAPDs showed the presence of some diagnostic bands in SH wheats that were absent in durum parents suggest that these bands are donated by D genome of the wild relative Ae. tauschii. PMID:23192610

Shakeel, Muhammad; Ilyas, Muhammad; Kazi, Mujeeb

2013-01-01

30

Field evaluation of emmer wheat-derived synthetic hexaploid wheat for resistance to Russian wheat aphid (Homoptera: Aphididae).  

PubMed

Broadening the genetic base for resistance to Russian wheat aphid, Diuraphis noxia (Mordvilko) (Homoptera: Aphididae), in bread wheat, Triticum aestivum L., is desirable. To date, identified Russian wheat aphid resistance genes are either located to the D chromosomes or to rye translocation of wheat, and resistance derived from the A or B genomes of tetraploid Triticum spp. would therefore be highly beneficial. Fifty-eight synthetic hexaploid wheat, derived from interspecific crosses of Triticum dicoccum Schrank. and Aegilops tauschii (Coss.) Schmal. and their parents were evaluated for resistance to Russian wheat aphid under field conditions. Plots infested with aphids were compared with plots protected with insecticides. The T. dicoccum parents were highly resistant to Russian wheat aphids, whereas the Ae. tauschii parents were susceptible. Resistance levels observed in the synthetic hexaploids were slightly below the levels of their T. dicoccum parents when a visual damage scale was used. but no major resistance suppression was observed among the synthetics. Russian wheat aphid infestation on average reduced plant height and kernel weight at harvest in the synthetic hexaploids and the T. dicoccum parents by 3-4%, whereas the susceptible control 'Seri M82' suffered losses of above 20%. Because resistance in the synthetic hexaploid wheat is derived from their T. dicoccum parent, resistance gene(s) must be located on the A and/or B genomes. They must therefore be different from previously identified Russian wheat aphid resistance genes, which have all been located on the D genome of wheat or on translocated segments. PMID:15279292

Lage, J; Skovmand, B; Andersen, S B

2004-06-01

31

Endothelial progenitors.  

PubMed

The studies carried out during the last two decades have represented a great effort in trying to identify and define cell populations endowed with the phenotypic and functional properties of endothelial progenitors. From these studies a scenario now emerges indicating that in the blood there are very rare endothelial progenitor cells, called endothelial colony-forming cells (ECFCs) or late outgrowth endothelial cells, not originated from bone marrow, capable of generating phenotypically and functionally competent endothelial cells, capable to be incorporated in vivo into growing vessels. ECFCs are present in the circulation as well as cells resident in the vascular endothelial intima. In addition to these progenitors, there are some hematopoietic progenitor cells capable of generating a monocytic cell progeny exerting a pro-angiogenic activity in vivo, but unable to be directly incorporated into growing vessels. These cells exert a pro-angiogenic effect in vivo through a paracrine mechanism based on the secretion of growth factors and cytokines. PMID:24332583

Pelosi, Elvira; Castelli, Germana; Testa, Ugo

2014-04-01

32

Starch characterisation and variability in GBSS loci of synthetic hexaploid wheats and their durum and Aegilops tauschii parents  

Microsoft Academic Search

Greater variability in starch properties is found in lower ploidy wheats than in commercial hexaploid wheats. This paper reports\\u000a on the starch properties and variability in granule bound starch synthase (GBSS) loci of 17 diploid (Aegilops tauschii) and 12 tetraploid (durums) potential progenitors of wheat, compared with 29 synthetic hexaploid wheats produced from such\\u000a progenitors. Starch properties examined were granule

C. M. Konik-Rose; S. Rahman; R. Appels; R. Moss; G. McMaster; D. R. Marshall; F. L. Stoddard

2009-01-01

33

[Inheritance of awn absence in tetraploid wheat species].  

PubMed

Awn absence was shown to be inherited as a dominant character in the tetraploid wheat species Triticum dicoccum (Schrank) Schuebl. and T. durum Desf. but as a recessive one in T. aethiopicum Jakubz. The monogenic control of the character was demonstrated for all studied species. In accessions of emmer and durum wheat, the character is controlled by the dominant gene B1, located on chromosome 5A, and in Ethiopian wheat, by a recessive gene, which we designated as awn. The recessive awn gene was localized on chromosome 3B of T. aethiopicum with the use of D-genome disomic substitution lines of cultivar Langdon. PMID:12760259

Goncharov, N P; Mitina, R L; Anfilova, N A

2003-04-01

34

Genetic diversity of wild emmer wheat in Israel and Turkey  

Microsoft Academic Search

Allozyme variation in the tetraploid wild emmer wheat, Triticum dicoccoides, the progenitor of all cultivated wheats, was studied for the proteins encoded by 42 gene loci in 1815 plants representing 37 populations - 33 from Israel and 4 from Turkey - sampled in 33 localities from 1979 to 1987. The results showed that: (a) 6 loci (14%) were monomorphic in

E. Nevo; A. Beiles

1989-01-01

35

Sequences of the Waxy Loci of Wheat: Utility in Analysis of Waxy Proteins and Developing Molecular Markers  

Microsoft Academic Search

The waxy proteins from a number of genetic backgrounds of wheat and its progenitors were analyzed by SDS-PAGE. The deduced amino acid sequences of the waxy proteins of three diploid progenitor species indicated several key amino acid substitutions, which could explain the differences observed in the electrophoretic mobilities of the wheat waxy proteins. A slight difference observed in the apparent

L. Yan; M. Bhave

2000-01-01

36

Wheat genomics  

Microsoft Academic Search

Wheat is the largest produced grain crop world-wide and has been extensively studied for a wide range of agronomic traits located across the genome. Its large chromosomes and the capacity of the polyploid genome to tolerate the addition or loss of chromosomes facilitated a fast progress in early wheat genetics using cytogenetic techniques. However, these same characteristics have limited the

Evans S Lagudah; Jorge Dubcovsky; Wayne Powell

2001-01-01

37

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

38

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

2008-07-15

39

Mammalian Megakaryocyte Progenitor Cell.  

National Technical Information Service (NTIS)

A substantially enriched mammalian hematopoietic cell population is provided, which is characterized as a progenitor cell committed to the megakaryocyte lineage. Methods are provided for the isolation and culture of these cells. The cell enrichment method...

T. N. Nakorn T. Miyamoto I. L. Weissman

2003-01-01

40

Chromosome locations of leaf rust resistance genes in selected tetraploid wheats through substitution lines  

Microsoft Academic Search

Langdon durum D-genome disomic substitution lines were used to study the chromosome locations of adult-plant leaf rust resistance genes identified from tetraploid wheat accessions. The accessions are 104 (Triticum turgidum subsp. dicoccum var. arras) and 127 (T. turgidum subsp. durum var. aestivum). The complete sets of the substitution lines were crossed as female parents with the accessions and F1 double

Shimelis Hussein; Johan J. Spies; Zakkie A. Pretorius; Maryke T. Labuschagne

2005-01-01

41

Nitrate reductases in hexaploid and tetraploid wheats and Aegilops.  

PubMed

Nitrate reductase activity (NR activity), protein content (NR protein) and polypeptides were compared in shoots of Triticum aestivum ssp. vulgare (L.) cv Fidel (bread wheat, AABBDD genome), Triticum dicoccum cv Vernal (AABB genome), Aegilops squarrosa var. strangulata (DD genome) and the amphiploid 365 (AABBDD genome), produced by crossing T. dicoccum cv Vernal and Ae. squarrosa var. strangulata. Constitutive NR protein and activity were found in shoots of all seedlings grown without nitrate, with the highest activity in the bread wheat. The inducible NR protein and activity developed upon the addition of nitrate. A 116-K polypeptide was identified as the main component of the NR from the bread wheat, while a faint, sometimes discernable 94-K band appeared on Western blots. Only one NR polypeptide could be identified in Ae. squarrosa -the 94 K. An intermediary situation was observed with the tetraploid T. dicoccum and the amphiploid: The 94-K polypeptide was the only one separated from NR of seedlings grown in the absence of nitrate. The 116-K polypeptide appeared after the addition of nitrate. The intensity of its band on the gel increased with the duration of the nitrate treatment. When comparing Ae. squarrosa and T. dicoccum, the constitutive isozyme (94-K polypeptide) was found in the D as well as in the AB genomes, while the inducible NR (116-K polypeptide) was absent from the D genome. Addition of the D genome into the AB genome slightly reinforced the expression of the inducible form (AB genome expression) in the amphiploid wheat. We postulate that the inducible form of NR in the bread wheat resulted from an evolutionary selection pressure favoured by cultivation. PMID:24226112

Ouhmidou, B; Cauderon, Y; Cherel, I; Champigny, M L

1990-01-01

42

RAPD polymorphism of wild emmer wheat populations, Triticum dicoccoides, in Israel  

Microsoft Academic Search

Genetic diversity in random amplified polymorphic DNAs (RAPDs) was studied in 110 genotypes of the tetraploid wild progenitor\\u000a of wheat, Triticum dicoccoides, from 11 populations sampled in Israel and Turkey. Our results show high level of diversity of RAPD markers in wild wheat\\u000a populations in Israel. The ten primers used in this study amplified 59 scorable RAPD loci of which

T. Fahima; G. L. Sun; A. Beharav; T. Krugman; A. Beiles; E. Nevo

1999-01-01

43

Lung Epithelial Progenitor Cells  

PubMed Central

The current enthusiasm for stem cell research stems from the hope that damaged or diseased tissues may one day be repaired through the manipulation of endogenous or exogenous stem cells. The postnatal human respiratory system is highly accessible and provides unique opportunities for the application of such techniques. Several putative adult lung epithelial stem cells have been identified in the mouse model system. However, their in vivo capabilities to contribute to different lineages, and their control mechanisms, remain unclear. If stem cell–based therapies are to be successful in the lung, it is vitally important that we understand the normal behavior of adult lung stem cells, and how this is regulated. Lung embryonic progenitor cells are much better defined and characterized than their adult counterparts. Moreover, experiments on a variety of developing tissues are beginning to uncover general mechanisms by which embryonic progenitors influence final organ size and structure. This provides a framework for the study of lung embryonic progenitor cells, facilitating experimental design and interpretation. A similar approach to investigating adult lung stem cells could produce rapid advances in the field.

Rawlins, Emma L.

2008-01-01

44

Wheat Outlook, April 2012.  

National Technical Information Service (NTIS)

USDA's National Agricultural Statistics Service (NASS), in its March 31 'Prospective Plantings', reported that all-wheat planted area for 2012 is forecast at 55.9 million acres, up 3 percent from the 2011 all-wheat planted area. U.S. wheat ending stocks f...

2012-01-01

45

Wheat Outlook, May 2012.  

National Technical Information Service (NTIS)

The 2012/13 outlook for U.S. wheat is for larger supplies and use, but lower prices. All wheat production is projected at 2,245 million bushels, up 12 percent from last years weather-reduced crop and the highest since 2008/09. The all wheat yield, project...

2012-01-01

46

Development of simple sequence repeat markers specific for the Lr34 resistance region of wheat using sequence information from rice and Aegilops tauschii.  

PubMed

Hexaploid wheat (Triticum aestivum L.) originated about 8,000 years ago from the hybridization of tetraploid wheat with diploid Aegilops tauschii Coss. containing the D-genome. Thus, the bread wheat D-genome is evolutionary young and shows a low degree of polymorphism in the bread wheat gene pool. To increase marker density around the durable leaf rust resistance gene Lr34 located on chromosome 7DS, we used molecular information from the orthologous region in rice. Wheat expressed sequence tags (wESTs) were identified by homology with the rice genes in the interval of interest, but were monomorphic in the 'Arina' x 'Forno' mapping population. To derive new polymorphic markers, bacterial artificial chromosome (BAC) clones representing a total physical size of approximately 1 Mb and belonging to four contigs were isolated from Ae. tauschii by hybridization screening with wheat ESTs. Several BAC clones were low-pass sequenced, resulting in a total of approximately 560 kb of sequence. Ten microsatellite sequences were found, and three of them were polymorphic in our population and were genetically mapped close to Lr34. Comparative analysis of marker order revealed a large inversion between the rice genome and the wheat D-genome. The SWM10 microsatellite is closely linked to Lr34 and has the same allele in the three independent sources of Lr34: 'Frontana', 'Chinese Spring', and 'Forno', as well in most of the genotypes containing Lr34. Therefore, SWM10 is a highly useful marker to assist selection for Lr34 in breeding programs worldwide. PMID:16896711

Bossolini, Eligio; Krattinger, Simon G; Keller, Beat

2006-10-01

47

Genetic analysis of wheat domestication and evolution under domestication  

PubMed Central

Wheat is undoubtedly one of the world's major food sources since the dawn of Near Eastern agriculture and up to the present day. Morphological, physiological, and genetic modifications involved in domestication and subsequent evolution under domestication were investigated in a tetraploid recombinant inbred line population, derived from a cross between durum wheat and its immediate progenitor wild emmer wheat. Experimental data were used to test previous assumptions regarding a protracted domestication process. The brittle rachis (Br) spike, thought to be a primary characteristic of domestication, was mapped to chromosome 2A as a single gene, suggesting, in light of previously reported Br loci (homoeologous group 3), a complex genetic model involved in spike brittleness. Twenty-seven quantitative trait loci (QTLs) conferring threshability and yield components (kernel size and number of kernels per spike) were mapped. The large number of QTLs detected in this and other studies suggests that following domestication, wheat evolutionary processes involved many genomic changes. The Br gene did not show either genetic (co-localization with QTLs) or phenotypic association with threshability or yield components, suggesting independence of the respective loci. It is argued here that changes in spike threshability and agronomic traits (e.g. yield and its components) are the outcome of plant evolution under domestication, rather than the result of a protracted domestication process. Revealing the genomic basis of wheat domestication and evolution under domestication, and clarifying their inter-relationships, will improve our understanding of wheat biology and contribute to further crop improvement.

Peleg, Zvi; Fahima, Tzion; Korol, Abraham B.; Abbo, Shahal; Saranga, Yehoshua

2011-01-01

48

Production and identification of wheat-Agropyron cristatum 6P translocation lines.  

PubMed

The narrow genetic background of wheat is the primary factor that has restricted the improvement of crop yield in recent years. The kernel number per spike is the most important factor of the many potential characteristics that determine wheat yield. Agropyron cristatum (L.) Gaertn., a wild relative of wheat, has the characteristics of superior numbers of florets and kernels per spike, which are controlled by chromosome 6P. In this study, the wheat-A. cristatum disomic addition and substitution lines were used as bridge materials to produce wheat-A. cristatum 6P translocation lines induced by gametocidal chromosomes and irradiation. The results of genomic in situ hybridization showed that the frequency of translocation induced by gametocidal chromosomes was 5.08%, which was higher than the frequency of irradiated hybrids (2.78%) and irradiated pollen (2.12%). The fluorescence in situ hybridization results of the translocation lines showed that A. cristatum chromosome 6P could be translocated to wheat ABD genome, and the recombination frequency was A genome > B genome > D genome. The alien A. cristatum chromosome 6P was translocated to wheat homoeologous groups 1, 2, 3, 5 and 6. We obtained abundant translocation lines that possessed whole-arm, terminal, segmental and intercalary translocations. Three 6PS-specific and four 6PL-specific markers will be useful to rapidly identify and trace the translocated fragments. The different wheat-A. cristatum 6P translocation lines obtained in this study can provide basic materials for analyzing the alien genes carried by chromosome 6P. The translocation line WAT33-1-3 and introgression lines WAI37-2 and WAI41-1, which had significant characteristics of multikernel (high numbers of kernels per spike), could be utilized as novel germplasms for high-yield wheat breeding. PMID:20490543

Luan, Yang; Wang, Xiaoguang; Liu, Weihua; Li, Chunye; Zhang, Jinpeng; Gao, Ainong; Wang, Yandong; Yang, Xinming; Li, Lihui

2010-07-01

49

Control of Galactosyl Diglycerides in Wheat Endosperm by Group 5 Chromosomes  

PubMed Central

Lower levels of monogalactosyl diglyceride (MGDG) and digalactosyl diglyceride (DGDG) have been found in tetraploid wheats as compared with those in hexaploid wheats. The same difference has been found between hexaploid cultivars and tetraploid lines derived from them by D genome extraction. A lower level of MGDG and DGDG is also present in Triticum carthlicum (AABB) as compared with Aegilops squarrosa (DD) or with the synthetic T. spelta (AABBDD) obtained from them. Analysis of the appropriate nullitetrasomic and ditelosomic lines indicates that a gene or genes located in the short arm of chromosome 5D are responsible for the observed difference and that group 5 chromosomes can be ranked as to their influence on the MGDG and DGDG levels in the order 5B > 5D > 5A and 5D > 5B > 5A, respectively. These results further support our previous identification of DGDG as the lipid factor responsible for petroleum ether solubility of lipopurothionins. Since DGDG contributes to baking quality by improving the retention of fermentation gases, the present observations imply that the difference in bread-making quality between the two types of wheat is not due only to proteins contributed by the D genome.

Hernandez-Lucas, C.; De Caleya, R. Fernandez; Carbonero, Pilar; Garcia-Olmedo, F.

1977-01-01

50

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

51

Short, natural, and extended photoperiod response in BC2F4 lines of bread wheat with different photoperiod-1 (Ppd-1) alleles.  

PubMed

Flowering is a critical period in the life cycle of flowering plant species, resulting in an irreversible commitment of significant resources. Wheat is photoperiod sensitive, flowering only when daylength surpasses a critical length; however, photoperiod insensitivity (PI) has been selected by plant breeders for >40 years to enhance yield in certain environments. Control of flowering time has been greatly facilitated by the development of molecular markers for the Photoperiod-1 (Ppd-1) homeoloci, on the group 2 chromosomes. In the current study, an allelic series of BC2F4 lines in the winter wheat cultivars 'Robigus' and 'Alchemy' was developed to elucidate the influence on flowering of eight gene variants from the B- and D-genomes of bread wheat and the A-genome of durum wheat. Allele effects were tested in short, natural, and extended photoperiods in the field and controlled environments. Across genetic background and treatment, the D-genome PI allele, Ppd-D1a, had a more potent effect on reducing flowering time than Ppd-B1a. However, there was significant donor allele effect for both Ppd-D1a and Ppd-B1a, suggesting the presence of linked modifier genes and/or additional sources of latent sensitivity. Development of Ppd-A1a BC2F4 lines derived from synthetic hexaploid wheat provided an opportunity to compare directly the flowering time effect of the A-genome allele from durum with the B- and D-genome variants from bread wheat for the first time. Analyses indicated that the reducing effect of Ppd-A1a is comparable with that of Ppd-D1a, confirming it as a useful alternative source of PI. PMID:23420880

Bentley, A R; Horsnell, R; Werner, C P; Turner, A S; Rose, G A; Bedard, C; Howell, P; Wilhelm, E P; Mackay, I J; Howells, R M; Greenland, A; Laurie, D A; Gosman, N

2013-04-01

52

Core Compactness of Progenitors  

NASA Astrophysics Data System (ADS)

The compactness of the core of a pre-supernova star is one of the important unexplored issues in progenitor evolution. Recent studies have found the core compactness to be varying non-monotonically as a function of ZAMS mass. In this work we have calculated a large grid of 1D full stellar and naked C/O core models using the implicit hydrodynamic code KEPLER and the open source stellar evolution code MESA, in order to gain a better insight in core compactness' dependence on the stellar mass and convection physics. We find the complicated evolution during C, O and Si burning phases act as the main cause of the non-monotonic variation of compactness, and the whole compactness curve as a function of mass to be quite dependent on the treatment of semiconvection. We also conclude that the C/O core mass is the main discriminant of pre-supernova structure.

Sukhbold, Tuguldur; Woosley, S. E.; Paxton, B.; Heger, A.

2013-04-01

53

Core Compactness of Progenitors  

NASA Astrophysics Data System (ADS)

The compactness of the core of a pre-supernova star is one of the important unexplored issues in progenitor evolution. Recent studies have found the core compactness to be varying non-monotonically as a function of ZAMS mass. In this work we have calculated a large grid of 1D full stellar and naked C/O core models using the implicit hydrodynamic code KEPLER and the open source stellar evolution code MESA, in order to gain a better insight in core compactness' dependence on the stellar mass and convection physics. We find the complicated evolution during C burning acts as the main cause of the non-monotonic variation of compactness, and the whole compactness curve as a function of mass to be quite dependent on the treatment of semiconvection. We also conclude that the C/O core mass is the main discriminant of pre-supernova structure.

Sukhbold, Tuguldur; Woosley, S. E.; Paxton, B.; Heger, A.

2013-01-01

54

Chromosomal rearrangements in wheat: their types and distribution.  

PubMed

Four hundred and sixty polyploid wheat accessions and 39 triticale forms from 37 countries of Europe, Asia, and USA were scored by C-banding for the presence of translocations. Chromosomal rearrangements were detected in 70 of 208 accessions of tetraploid wheat, 69 of 252 accessions of hexaploid wheat, and 3 of 39 triticale forms. Altogether, 58 types of major chromosomal rearrangements were identified in the studied material; they are discussed relative to 11 additional translocation types described by other authors. Six chromosome modifications of unknown origin were also observed. Among all chromosomal aberrations identified in wheat, single translocations were the most frequent type (39), followed by multiple rearrangements (9 types), pericentric inversions (9 types), and paracentric inversions (3 types). According to C-banding analyses, the breakpoints were located at or near the centromere in 60 rearranged chromosomes, while in 52 cases they were in interstitial chromosome regions. In the latter case, translocation breakpoints were often located at the border of C-bands and the euchromatin region or between two adjacent C-bands; some of these regions seem to be translocation "hotspots". Our results and data published by other authors indicate that the B-genome chromosomes are involved in translocations most frequently, followed by the A- and D-genome chromosomes; individual chromosomes also differ in the frequencies of translocations. Most translocations were detected in 1 or 2 accessions, and only 11 variants showed relatively high frequencies or were detected in wheat varieties of different origins or from different species. High frequencies of some translocations with a very restricted distribution could be due to a "bottleneck effect". Other types seem to occur independently and their broad distribution can result from selective advantages of rearranged genotypes in diverse environmental conditions. We found significant geographic variation in the spectra and frequencies of translocation in wheat: the highest proportions of rearranged genotypes were found in Central Asia, the Middle East, Northern Africa, and France. A low proportion of aberrant genotypes was characteristic of tetraploid wheat from Transcaucasia and hexaploid wheat from Middle Asia and Eastern Europe. PMID:18059554

Badaeva, E D; Dedkova, O S; Gay, G; Pukhalskyi, V A; Zelenin, A V; Bernard, S; Bernard, M

2007-10-01

55

The gene space in wheat: the complete ?-gliadin gene family from the wheat cultivar Chinese Spring.  

PubMed

The complete set of unique ?-gliadin genes is described for the wheat cultivar Chinese Spring using a combination of expressed sequence tag (EST) and Roche 454 DNA sequences. Assemblies of Chinese Spring ESTs yielded 11 different ?-gliadin gene sequences. Two of the sequences encode identical polypeptides and are assumed to be the result of a recent gene duplication. One gene has a 3' coding mutation that changes the reading frame in the final eight codons. A second assembly of Chinese Spring ?-gliadin sequences was generated using Roche 454 total genomic DNA sequences. The 454 assembly confirmed the same 11 active genes as the EST assembly plus two pseudogenes not represented by ESTs. These 13 ?-gliadin sequences represent the complete unique set of ?-gliadin genes for cv Chinese Spring, although not ruled out are additional genes that are exact duplications of these 13 genes. A comparison with the ESTs of two other hexaploid cultivars (Butte 86 and Recital) finds that the most active genes are present in all three cultivars, with exceptions likely due to too few ESTs for detection in Butte 86 and Recital. A comparison of the numbers of ESTs per gene indicates differential levels of expression within the ?-gliadin gene family. Genome assignments were made for 6 of the 13 Chinese Spring ?-gliadin genes, i.e., one assignment from a match to two ?-gliadin genes found within a tetraploid wheat A genome BAC and four genes that match four distinct ?-gliadin sequences assembled from Roche 454 sequences from Aegilops tauschii, the hexaploid wheat D-genome ancestor. PMID:23564033

Anderson, Olin D; Huo, Naxin; Gu, Yong Q

2013-06-01

56

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

57

Types and rates of sequence evolution at the high-molecular-weight glutenin locus in hexaploid wheat and its ancestral genomes.  

PubMed

The Glu-1 locus, encoding the high-molecular-weight glutenin protein subunits, controls bread-making quality in hexaploid wheat (Triticum aestivum) and represents a recently evolved region unique to Triticeae genomes. To understand the molecular evolution of this locus region, three orthologous Glu-1 regions from the three subgenomes of a single hexaploid wheat species were sequenced, totaling 729 kb of sequence. Comparing each Glu-1 region with its corresponding homologous region from the D genome of diploid wheat, Aegilops tauschii, and the A and B genomes of tetraploid wheat, Triticum turgidum, revealed that, in addition to the conservation of microsynteny in the genic regions, sequences in the intergenic regions, composed of blocks of nested retroelements, are also generally conserved, although a few nonshared retroelements that differentiate the homologous Glu-1 regions were detected in each pair of the A and D genomes. Analysis of the indel frequency and the rate of nucleotide substitution, which represent the most frequent types of sequence changes in the Glu-1 regions, demonstrated that the two A genomes are significantly more divergent than the two B genomes, further supporting the hypothesis that hexaploid wheat may have more than one tetraploid ancestor. PMID:17028342

Gu, Yong Qiang; Salse, Jérôme; Coleman-Derr, Devin; Dupin, Adeline; Crossman, Curt; Lazo, Gerard R; Huo, Naxin; Belcram, Harry; Ravel, Catherine; Charmet, Gilles; Charles, Mathieu; Anderson, Olin D; Chalhoub, Boulos

2006-11-01

58

Genetic diversity for grain nutrients in wild emmer wheat: potential for wheat improvement  

PubMed Central

Background and Aims Micronutrient malnutrition, particularly zinc and iron deficiency, afflicts over three billion people worldwide due to low dietary intake. In the current study, wild emmer wheat (Triticum turgidum ssp. dicoccoides), the progenitor of domesticated wheat, was tested for (1) genetic diversity in grain nutrient concentrations, (2) associations among grain nutrients and their relationships with plant productivity, and (3) the association of grain nutrients with the eco-geographical origin of wild emmer accessions. Methods A total of 154 genotypes, including wild emmer accessions from across the Near Eastern Fertile Crescent and diverse wheat cultivars, were characterized in this 2-year field study for grain protein, micronutrient (zinc, iron, copper and manganese) and macronutrient (calcium, magnesium, potassium, phosphorus and sulphur) concentrations. Key Results Wide genetic diversity was found among the wild emmer accessions for all grain nutrients. The concentrations of grain zinc, iron and protein in wild accessions were about two-fold greater than in the domesticated genotypes. Concentrations of these compounds were positively correlated with one another, with no clear association with plant productivity, suggesting that all three nutrients can be improved concurrently with no yield penalty. A subset of 12 populations revealed significant genetic variation between and within populations for all minerals. Association between soil characteristics at the site of collection and grain nutrient concentrations showed negative associations between soil clay content and grain protein and between soil-extractable zinc and grain zinc, the latter suggesting that the greatest potential for grain nutrient minerals lies in populations from micronutrient-deficient soils. Conclusions Wild emmer wheat germplasm offers unique opportunities to exploit favourable alleles for grain nutrient properties that were excluded from the domesticated wheat gene pool.

Chatzav, Merav; Peleg, Zvi; Ozturk, Levent; Yazici, Atilla; Fahima, Tzion; Cakmak, Ismail; Saranga, Yehoshua

2010-01-01

59

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

60

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

61

Three genomes differentially contribute to the biosynthesis of benzoxazinones in hexaploid wheat.  

PubMed

Hexaploid wheat (Triticum aestivum) accumulates benzoxazinones (Bxs) as defensive compounds. Previously, we found that five Bx biosynthetic genes, TaBx1-TaBx5, are located on each of the three genomes (A, B, and D) of hexaploid wheat. In this study, we isolated three homoeologous cDNAs of each TaBx gene to estimate the contribution of individual homoeologous TaBx genes to the biosynthesis of Bxs in hexaploid wheat. We analyzed their transcript levels by homoeolog- or genome-specific quantitative RT-PCR and the catalytic properties of their translation products by kinetic analyses using recombinant TaBX enzymes. The three homoeologs were transcribed differentially, and the ratio of the individual homoeologous transcripts to total homoeologous transcripts also varied with the tissue, i.e., shoots or roots, as well as with the developmental stage. Moreover, the translation products of the three homoeologs had different catalytic properties. Some TaBx homoeologs were efficiently transcribed, but the translation products showed only weak enzymatic activities, which inferred their weak contribution to Bx biosynthesis. Considering the transcript levels and the catalytic properties collectively, we concluded that the homoeologs on the B genome generally contributed the most to the Bx biosynthesis in hexaploid wheat, especially in shoots. In tetraploid wheat and the three diploid progenitors of hexaploid wheat, the respective transcript levels of the TaBx homoeologs were similar in ratio to those observed in hexaploid wheat. This result indicates that the genomic bias in the transcription of the TaBx genes in hexaploid wheat originated in the diploid progenitors and has been retained through the polyploidization. PMID:16260753

Nomura, Taiji; Ishihara, Atsushi; Yanagita, Ryo C; Endo, Takashi R; Iwamura, Hajime

2005-11-01

62

Genetic characterization and mapping of the Rht-1 homoeologs and flanking sequences in wheat.  

PubMed

The introgression of Reduced height (Rht)-B1b and Rht-D1b into bread wheat (Triticum aestivum) varieties beginning in the 1960s led to improved lodging resistance and yield, providing a major contribution to the 'green revolution'. Although wheat Rht-1 and surrounding sequence is available, the genetic composition of this region has not been examined in a homoeologous series. To determine this, three Rht-1-containing bacterial artificial chromosome (BAC) sequences derived from the A, B, and D genomes of the bread wheat variety Chinese Spring (CS) were fully assembled and analyzed. This revealed that Rht-1 and two upstream genes were highly conserved among the homoeologs. In contrast, transposable elements (TEs) were not conserved among homoeologs with the exception of intronic miniature inverted-repeat TEs (MITEs). In relation to the Triticum urartu ancestral line, CS-A genic sequences were highly conserved and several colinear TEs were present. Comparative analysis of the CS wheat BAC sequences with assembled Poaceae genomes showed gene synteny and amino acid sequences were well preserved. Further 5' and 3' of the wheat BAC sequences, a high degree of gene colinearity is present among the assembled Poaceae genomes. In the 20 kb of sequence flanking Rht-1, five conserved non-coding sequences (CNSs) were present among the CS wheat homoeologs and among all the Poaceae members examined. Rht-A1 was mapped to the long arm of chromosome 4 and three closely flanking genetic markers were identified. The tools developed herein will enable detailed studies of Rht-1 and linked genes that affect abiotic and biotic stress response in wheat. PMID:23381809

Wilhelm, Edward P; Howells, Rhian M; Al-Kaff, Nadia; Jia, Jizeng; Baker, Catherine; Leverington-Waite, Michelle A; Griffiths, Simon; Greenland, Andy J; Boulton, Margaret I; Powell, Wayne

2013-05-01

63

Length variations of i-type low-molecular-weight glutenin subunit genes in diploid wheats.  

PubMed

Allelic variation of the low-molecular-weight glutenin subunit (LMW-GS) is associated with the significant differences of dough quality in bread and durum wheat, and has been widely evaluated at protein level in wheat and its relatives. In this study, a PCR primer set, targeting the high variable repetitive domains, was employed to assay the length variation of i-type LMW-GS genes in the A-genomes of diploid wheats, the diploid progenitors of tetraploid and hexaploid wheat. A total of 71 accessions of diploid wheats, belonging to two wild and one cultivated species, were investigated. The higher variations of repetitive length in i-type LMW-GS genes were found in diploid wheats with Nei's genetic variation index (H) of 0.834. The two wild species, T. boeoticum and T. urartu, were found to possess the similar degree of variability, with the Nei's genetic variation index of 0.806 and 0.783, respectively. Less variations were detected in T. monococcum (H = 0.680), a cultivated species domesticated from T. boeoticum. The sufficient variations found in this study could be used as valuable sources for the enrichment of the genetic variations and the alteration of flour-processing properties of the cultivated wheat. To our knowledge, it was the first time that an analysis of length variation targeting a particular group of genes of LMW-GS complex multigene families was conducted. PMID:18666554

Long, H; Huang, Z; Wei, Y-M; Yan, Z-H; Ma, Z-C; Zheng, Y-L

2008-04-01

64

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

65

PRODUCTION AND CYTOGENETICS OF A NEW THINOPYRUM ELONGATUM \\/ TRITICUM AESTIVUM HYBRID, ITS AMPHIPLOID AND BACKCROSS DERIVATIVES  

Microsoft Academic Search

Genetic diversity is crucial for crop improvement. In wheat this resource is distributed within the three gene pools of the tribe Triticeae and priority usage over the last decade has been with the D genome diploid progenitor of the primary gene pool. Potent variability that contributes towards resistance\\/ tolerance to key biotic\\/abiotic stresses limiting wheat production is also available in

ABDUL MUJEEB-KAZI; ALEJANDRO CORTES; ALVINA GUL; MUHAMMAD FAROOQ; FARAH MAJEED; IFTIKHAR AHMAD; MANILAL WILLIAM; VICTOR ROSAS; ROMAN DELGADO

66

High-Resolution Radiation Hybrid Map of Wheat Chromosome 1D  

PubMed Central

Physical mapping methods that do not rely on meiotic recombination are necessary for complex polyploid genomes such as wheat (Triticum aestivum L.). This need is due to the uneven distribution of recombination and significant variation in genetic to physical distance ratios. One method that has proven valuable in a number of nonplant and plant systems is radiation hybrid (RH) mapping. This work presents, for the first time, a high-resolution radiation hybrid map of wheat chromosome 1D (D genome) in a tetraploid durum wheat (T. turgidum L., AB genomes) background. An RH panel of 87 lines was used to map 378 molecular markers, which detected 2312 chromosome breaks. The total map distance ranged from ?3,341 cR35,000 for five major linkage groups to 11,773 cR35,000 for a comprehensive map. The mapping resolution was estimated to be ?199 kb/break and provided the starting point for BAC contig alignment. To date, this is the highest resolution that has been obtained by plant RH mapping and serves as a first step for the development of RH resources in wheat.

Kalavacharla, Venu; Hossain, Khwaja; Gu, Yong; Riera-Lizarazu, Oscar; Vales, M. Isabel; Bhamidimarri, Suresh; Gonzalez-Hernandez, Jose L.; Maan, Shivcharan S.; Kianian, Shahryar F.

2006-01-01

67

Explosibility of Australian Wheat Dusts.  

National Technical Information Service (NTIS)

The purpose of the investigation was to assess the explosive characteristics of the dusts produced from various grades of wheat grown in Australia. Dust samples were collected at country silos and export terminals for wheat grown in northern and southern ...

R. J. Enright M. H. Bullock

1983-01-01

68

Occurrence of Trichothecin in Wheat  

PubMed Central

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.

Ishii, Kenji; Kobayashi, Jun; Ueno, Yoshio; Ichinoe, Masakatsu

1986-01-01

69

A Microsatellite Map of Wheat  

Microsoft Academic Search

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

Marion S. Roder; Victor Korzun; Katja Wendehake; Jens Plaschke; Marie-Helene Tixier; Philippe Leroy; Martin W. Ganal

70

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

2011-02-01

71

Biofortification of wheat grain with iron and zinc: integrating novel genomic resources and knowledge from model crops  

PubMed Central

Wheat, like many other staple cereals, contains low levels of the essential micronutrients iron and zinc. Up to two billion people worldwide suffer from iron and zinc deficiencies, particularly in regions with predominantly cereal-based diets. Although wheat flour is commonly fortified during processing, an attractive and more sustainable solution is biofortification, which requires developing new varieties of wheat with inherently higher iron and zinc content in their grains. Until now most studies aimed at increasing iron and zinc content in wheat grains have focused on discovering natural variation in progenitor or related species. However, recent developments in genomics and transformation have led to a step change in targeted research on wheat at a molecular level. We discuss promising approaches to improve iron and zinc content in wheat using knowledge gained in model grasses. We explore how the latest resources developed in wheat, including sequenced genomes and mutant populations, can be exploited for biofortification. We also highlight the key research and practical challenges that remain in improving iron and zinc content in wheat.

Borrill, Philippa; Connorton, James M.; Balk, Janneke; Miller, Anthony J.; Sanders, Dale; Uauy, Cristobal

2014-01-01

72

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

73

Reckoning wheat yield trends  

NASA Astrophysics Data System (ADS)

Wheat yields have increased approximately linearly since the mid-twentieth century across the globe, but stagnation of these trends has now been suggested for several nations. We present a new statistical test for whether a yield time series has leveled off and apply it to wheat yield data from 47 different regions to show that nearly half of the production within our sample has transitioned to level trajectories. With the major exception of India, the majority of leveling in wheat yields occurs within developed nations—including the United Kingdom, France and Germany—whose policies appear to have disincentivized yield increases relative to other objectives. The effects of climate change and of yields nearing their maximum potential may also be important.

Lin, M.; Huybers, P.

2012-06-01

74

A diploid wheat TILLING resource for wheat functional genomics  

PubMed Central

Background Triticum monococcum L., an A genome diploid einkorn wheat, was the first domesticated crop. As a diploid, it is attractive genetic model for the study of gene structure and function of wheat-specific traits. Diploid wheat is currently not amenable to reverse genetics approaches such as insertion mutagenesis and post-transcriptional gene silencing strategies. However, TILLING offers a powerful functional genetics approach for wheat gene analysis. Results We developed a TILLING population of 1,532 M2 families using EMS as a mutagen. A total of 67 mutants were obtained for the four genes studied. Waxy gene mutation frequencies are known to be 1/17.6 - 34.4 kb DNA in polyploid wheat TILLING populations. The T. monococcum diploid wheat TILLING population had a mutation frequency of 1/90 kb for the same gene. Lignin biosynthesis pathway genes- COMT1, HCT2, and 4CL1 had mutation frequencies of 1/86 kb, 1/92 kb and 1/100 kb, respectively. The overall mutation frequency of the diploid wheat TILLING population was 1/92 kb. Conclusion The mutation frequency of a diploid wheat TILLING population was found to be higher than that reported for other diploid grasses. The rate, however, is lower than tetraploid and hexaploid wheat TILLING populations because of the higher tolerance of polyploids to mutations. Unlike polyploid wheat, most mutants in diploid wheat have a phenotype amenable to forward and reverse genetic analysis and establish diploid wheat as an attractive model to study gene function in wheat. We estimate that a TILLING population of 5, 520 will be needed to get a non-sense mutation for every wheat gene of interest with 95% probability.

2012-01-01

75

Characterization of HMW-GS and evaluation of their diversity in morphologically elite synthetic hexaploid wheats.  

PubMed

High molecular weight glutenin subunit composition and variation in 95 Elite-1 synthetic hexaploid (SH) wheats (Triticum turgidum/Aegilops tauschii; 2n = 6× = 42; AABBDD) were determined by sodium dodecyl sulphate polyacrylamide gel electrophoresis method (SDS-PAGE). Twenty two different alleles at Glu-1 loci in SHs were observed. Forty four different patterns of HMW-GS in synthetics were found. This higher HMW glutenin composition was due to higher proportion of D-genome encoded subunits in these SHs. 8% urea/SDS-PAGE better discriminated subunit 2* than 12% gels. However 12% urea/SDS-PAGE allowed differentiated mobility of Glu-D(t)1 subunits. Genetic variability at Glu-D(t)1 locus was greater than Glu-A1 and Glu-B1 loci. The relative high frequency of superior alleles, Glu-B1b and Glu-D(t)1d indicated the superior bread making quality attributes embedded in these synthetic hexaploid wheats. Of the 95 Elite-1 SHs 27.1% possessed superior alleles at Glu-A1 and 51% had superior alleles at Glu-B1 locus. At Glu-D(t)1 frequency of inferior allele 1Dx2 + 1Dy12 was very low (5.26%) and nine different rare alleles along with the higher frequency (22.1%) of D-genome encoded subunit, 1Dx5 + 1Dy10, were observed. These superior alleles shall form the priority selective sieve for their usage in wheat improvement efforts. PMID:23341752

Rasheed, Awais; Safdar, Tania; Gul-Kazi, Alvina; Mahmood, Tariq; Akram, Zahid; Mujeeb-Kazi, Abdul

2012-12-01

76

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

77

Endothelial progenitor cells for vasculogenesis.  

PubMed

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. PMID:15653838

Murasawa, Satoshi; Asahara, Takayuki

2005-02-01

78

Circulating progenitor cells and scleroderma  

Microsoft Academic Search

Scleroderma (systemic sclerosis) is a disease of unknown origins that involves tissue ischemia and fibrosis in the skin and\\u000a internal organs such as the lungs. The tissue ischemia is due to a lack of functional blood vessels and an inability to form\\u000a new blood vessels. Bone marrow-derived circulating endothelial progenitor cells play a key role in blood vessel repair and

Richard H. Gomer

2008-01-01

79

Progenitors of Recombining Supernova Remnants  

NASA Astrophysics Data System (ADS)

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.

2012-05-01

80

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

81

Registration of ‘Brick’ Wheat  

Microsoft Academic Search

Alice' (Reg. No. CV-1023, PI 644223) hard white winter wheat (Triticum aestivum L.) was developed by the South Dakota Agricultural Experiment Station and released in 2006 to seed producers by the developing institution and the Nebraska Agricultural Experiment Station. Alice was selected from the cross 'Abilene' (PI 511307)\\/'Karl' (PI 527480) made in 1992 at Brookings, SD. Alice was selected as

K. D. Glover; J. C. Rudd; R. N. Devkota; R. G. Hall; Y. Jin; L. E. Osborne; J. A. Ingemansen; J. R. Rickertsen; D. D. Baltensperger; G. A. Hareland

2010-01-01

82

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

2013-01-01

83

Hypersensitive Response-Like Reaction Is Associated with Hybrid Necrosis in Interspecific Crosses between Tetraploid Wheat and Aegilops tauschii Coss  

PubMed Central

Background Hybrid speciation is classified into homoploid and polyploid based on ploidy level. Common wheat is an allohexaploid species that originated from a naturally occurring interploidy cross between tetraploid wheat and diploid wild wheat Aegilops tauschii Coss. Aegilops tauschii provides wide naturally occurring genetic variation. Sometimes its triploid hybrids with tetraploid wheat show the following four types of hybrid growth abnormalities: types II and III hybrid necrosis, hybrid chlorosis, and severe growth abortion. The growth abnormalities in the triploid hybrids could act as postzygotic hybridization barriers to prevent formation of hexaploid wheat. Methodology/Principal Findings Here, we report on the geographical and phylogenetic distribution of Ae. tauschii accessions inducing the hybrid growth abnormalities and showed that they are widely distributed across growth habitats in Ae. tauschii. Molecular and cytological characterization of the type III necrosis phenotype was performed. The hybrid abnormality causing accessions were widely distributed across growth habitats in Ae. tauschii. Transcriptome analysis showed that a number of defense-related genes such as pathogenesis-related genes were highly up-regulated in the type III necrosis lines. Transmission electron microscope observation revealed that cell death occurred accompanied by generation of reactive oxygen species in leaves undergoing type III necrosis. The reduction of photosynthetic activity occurred prior to the appearance of necrotic symptoms on the leaves exhibiting hybrid necrosis. Conclusions/Significance Taking these results together strongly suggests that an autoimmune response might be triggered by intergenomic incompatibility between the tetraploid wheat and Ae. tauschii genomes in type III necrosis, and that genetically programmed cell death could be regarded as a hypersensitive response-like cell death similar to that observed in Arabidopsis intraspecific and Nicotiana interspecific hybrids. Only Ae. tauschii accessions without such inhibiting factors could be candidates for the D-genome donor for the present hexaploid wheat.

Mizuno, Nobuyuki; Hosogi, Naoki; Park, Pyoyun; Takumi, Shigeo

2010-01-01

84

An estimation of the minimum number of SSR alleles needed to reveal genetic relationships in wheat varieties. I. Information from large-scale planted varieties and cornerstone breeding parents in Chinese wheat improvement and production.  

PubMed

The genetic relationships of 43 wheat varieties were analyzed with SSR markers. The materials employed included 14 cornerstone breeding parents used before 1980 and another 29 other large-scale planted varieties currently in use in China. A total of 501 different alleles were amplified, including 166 alleles of the A genome, 174 of the B genome and 161 of the D genome. Data obtained were used to estimate genetic similarity using the DICE coefficient, and dendrograms were constructed using the UPGMA method. The dendrogram with 501 alleles successfully differentiated all the cornerstone breeding parents and the large-scale planted varieties, and the dendogram tree was basically consistent with the pedigrees of these varieties. The correlation coefficient between the genetic distance matrix of 501 alleles and that of 450 was 0.99. Correlation coefficients among random samples of alleles suggested that 350 to 400 alleles were needed to detect genetic relationships among common wheat varieties. Correlation coefficients of a genetic similarity matrix based on 580, and those of 501 and 400, random alleles were 0.96 and 0.94, respectively. However, there were marked differences between the matrix based on the 501 alleles and those based on markers located on the A-, B- or D-genome independently. The correlation coefficients between the genetic distance matrix of 501 alleles and alleles within A, B or D genomes were 0.77, 0.76 and 0.67. The estimation of genetic similarity should be based on data from all genomes rather than any one genome. PMID:12582878

Zhang, X Y; Li, C W; Wang, L F; Wang, H M; You, G X; Dong, Y S

2002-12-01

85

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

2012-12-01

86

Wheat Invertases 1  

PubMed Central

Wheat coleoptiles have two distinct invertases, a soluble and a cell wall-bound form as indicated by results from cytochemical and biochemical studies. These enzyme activities differ in their pH optima, chromatographic behavior on diethylaminoethyl cellulose, kinetic properties, thermal stability, and response to light treatment. The soluble invertase was purified to near homogeneity by diethylaminoethyl-cellulose, concanavalin-A Sepharose, and Sephacryl S-300 chromatography. The overall purification was 175-fold with a recovery of about 26%. The holoenzyme has an apparent molecular weight of 158,000 and subunit molecular weight of 53,000 as estimated by polyacrylamide gel electrophoresis under denaturing conditions. Illumination of wheat seedlings caused an increase in the cell wall, but not the soluble, invertase activity. Images Fig. 1 Fig. 4

Krishnan, Hari B.; Blanchette, Joan T.; Okita, Thomas W.

1985-01-01

87

Identifying progenitors of core-collapse supernovae  

Microsoft Academic Search

Observations of massive stars - before they explode - provide direct identification of SN progenitors. Such studies require the combination of a deep, high-resolution image of the SN location, serendipitously obtained before it exploded, with a precise localization of the SN (after it exploded) to enable us to select the correct progenitor from among the stars in the pre-explosion SN

Avishay Gal-Yam; Douglas Leonard; Derek Fox; Yoav Green

2010-01-01

88

Identifying progenitors of core-collapse supernovae  

Microsoft Academic Search

Direct observations of massive stars - before they explode - provide a model free identification of SN progenitors. Such studies require the combination of a deep, high-resolution image of the SN location, serendipitously obtained before it exploded, with a precise localization of the SN (after it exploded) to enable us to select the correct progenitor from among the stars in

Avishay Gal-Yam; Douglas Leonard; Derek Fox

2008-01-01

89

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

90

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

91

GRB Progenitors and Observational Criteria  

NASA Astrophysics Data System (ADS)

Phenomenologically, two classes of GRBs (long/soft vs. short/hard) are identified based on their ?-ray properties. The boundary between the two classes is vague. Multi-wavelength observations lead to identification of two types of GRB progenitors: one related to massive stars (Type II), and another related to compact stars (Type I). Evidence suggests that the majority of long GRBs belong to Type II, while at least the majority of nearby short GRBs belong to Type I. Nonetheless, counter examples do exist. Both long-duration Type I and short-duration Type II GRBs have been observed. In this talk, I review the complications in GRB classification and efforts in diagnosing GRB progenitors based on multiple observational criteria. In particular, I raise the caution to readily accept that all short/hard GRBs detected by BATSE are due to compact star mergers. Finally, I propose to introduce ``amplitude'' as the third dimension (besides ``duration'' and ``hardness'') to quantify burst properties, and point out that the ``tip-of-the-iceberg'' effect may introduce confusion in defining the physical category of GRBs, especially for low-amplitude, high-redshift GRBs.

Zhang, Bing

2012-09-01

92

Olfactory control of blood progenitor maintenance.  

PubMed

Drosophila hematopoietic progenitor maintenance involves both near neighbor and systemic interactions. This study shows that olfactory receptor neurons (ORNs) function upstream of a small set of neurosecretory cells that express GABA. Upon olfactory stimulation, GABA from these neurosecretory cells is secreted into the circulating hemolymph and binds to metabotropic GABAB receptors expressed on blood progenitors within the hematopoietic organ, the lymph gland. The resulting GABA signal causes high cytosolic Ca(2+), which is necessary and sufficient for progenitor maintenance. Thus, the activation of an odorant receptor is essential for blood progenitor maintenance, and consequently, larvae raised on minimal odor environments fail to sustain a pool of hematopoietic progenitors. This study links sensory perception and the effects of its deprivation on the integrity of the hematopoietic and innate immune systems in Drosophila. PAPERCLIP: PMID:24267893

Shim, Jiwon; Mukherjee, Tina; Mondal, Bama Charan; Liu, Ting; Young, Gloria Chin; Wijewarnasuriya, Dinali Priasha; Banerjee, Utpal

2013-11-21

93

Drought and salt tolerances in wild relatives for wheat and barley improvement.  

PubMed

Drought and salinity are the major abiotic stresses that dramatically threaten the food supply in the world. Tribe Triticeae, including wheat and barley, possesses tremendous potential for drought and salt tolerance that has been extensively and practically identified, tested, and transferred to wheat cultivars with proven expression of tolerance in experimental trials. Triticum dicoccoides and Hordeum spontaneum, the progenitors of cultivated wheat and barley, have adapted to a broad range of environments and developed rich genetic diversities for drought and salt tolerances. Drought- and salt-tolerant genes and quantitative trait loci (QTLs) have been identified in T. dicoccoides and H. spontaneum and have great potential in wheat and barley improvement. Advanced backcross QTL analysis, the introgression libraries based on wild wheat and wild barley as donors, and positional cloning of natural QTLs will play prevailing roles in elucidating the molecular control of drought and salt tolerance. Combining tolerant genes and QTLs in crop breeding programs aimed at improving tolerance to drought and salinity will be achieved within a multidisciplinary context. Wild genetic resistances to drought and salinity will be shifted in the future from field experiments to the farmer. PMID:20040064

Nevo, Eviatar; Chen, Guoxiong

2010-04-01

94

Immunochemical characteristics of wheat proteins  

Microsoft Academic Search

The purpose of this paper is to provide a comprehensive overview of wheat protein characteristics and of enzyme-linked immunosorbent assay (ELISA) technique for wheat quality characteristics determination. Literature review is to report the identification of low and high molecular weight subunits of glutenins with ELISA. Immunological assay has been reported to be used as an alternative method to reduce the

Moazzam Rafiq Khan; Faqir Muhammad Anjum; Ahmad Din; Shahzad Hussain; Muhammad Asim Shabbir; Muhammad Nadeem

2010-01-01

95

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

96

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

2009-06-01

97

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

98

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

99

Wheat Alcohol Dehydrogenase Isozymes  

PubMed Central

Evidence in support of the hypothesis of gene expression and subunit association suggested earlier for Triticum alcohol dehydrogenase has been obtained through purification and partial characterization of the enzyme from tetraploid wheat. Three isozymes of alcohol dehydrogenase were separated and purified to apparent homogeneity using streptomycin sulfate precipitation, gel filtration chromatography, and anion exchange chromatography. The isozymes are dimers with the same molecular weight (116,000 ± 2,000), but significantly different isoelectric pH values. The Michaelis constants for NAD+ and ethanol are 0.1 millimolar and 12 millimolar, respectively. The substrate specificity of the three alcohol dehydrogenase isozymes was investigated. Images

Langston, Pat J.; Pace, C. Nick; Hart, Gary E.

1980-01-01

100

Drought Tolerance in Wheat  

PubMed Central

Drought is one of the most important phenomena which limit crops' production and yield. Crops demonstrate various morphological, physiological, biochemical, and molecular responses to tackle drought stress. Plants' vegetative and reproductive stages are intensively influenced by drought stress. Drought tolerance is a complicated trait which is controlled by polygenes and their expressions are influenced by various environmental elements. This means that breeding for this trait is so difficult and new molecular methods such as molecular markers, quantitative trait loci (QTL) mapping strategies, and expression patterns of genes should be applied to produce drought tolerant genotypes. In wheat, there are several genes which are responsible for drought stress tolerance and produce different types of enzymes and proteins for instance, late embryogenesis abundant (lea), responsive to abscisic acid (Rab), rubisco, helicase, proline, glutathione-S-transferase (GST), and carbohydrates during drought stress. This review paper has concentrated on the study of water limitation and its effects on morphological, physiological, biochemical, and molecular responses of wheat with the possible losses caused by drought stress.

Prodhan, Zakaria Hossain; Faruq, Golam

2013-01-01

101

On the progenitor of supernova 1987 A  

Microsoft Academic Search

A previously unpublished ultralow-dispersion spectrum of Sand- uleak -69 202, the stellar progenitor of SN 1987A, is presented and the uncertain presupernova evolution of Sanduleak -69 202 is discussed.

M. Parthasarathy; David Branch; E. Baron; David J. Jeffery

2006-01-01

102

On the Progenitor of Supernova 1987A  

Microsoft Academic Search

A previously unpublished ultralow-dispersion spectrum of Sanduleak -69 202,\\u000athe stellar progenitor of SN 1987A, is presented and the uncertain presupernova\\u000aevolution of Sanduleak -69 202 is discussed.

M. Parthasarathy; David Branch; E. Baron; David J. Jeffery

2006-01-01

103

Simultaneous transfer, introgression, and genomic localization of genes for resistance to stem rust race TTKSK (Ug99) from Aegilops tauschii to wheat.  

PubMed

Wheat production is currently threatened by widely virulent races of the wheat stem rust fungus, Puccinia graminis f. sp. tritici, that are part of the TTKSK (also known as 'Ug99') race group. The diploid D genome donor species Aegilops tauschii (2n = 2x = 14, DD) is a readily accessible source of resistance to TTKSK and its derivatives that can be transferred to hexaploid wheat, Triticum aestivum (2n = 6x = 42, AABBDD). To expedite transfer of TTKSK resistance from Ae. tauschii, a direct hybridization approach was undertaken that integrates gene transfer, mapping, and introgression into one process. Direct crossing of Ae. tauschii accessions with an elite wheat breeding line combines the steps of gene transfer and introgression while development of mapping populations during gene transfer enables the identification of closely linked markers. Direct crosses were made using TTKSK-resistant Ae. tauschii accessions TA1662 and PI 603225 as males and a stem rust-susceptible T. aestivum breeding line, KS05HW14, as a female. Embryo rescue enabled recovery of F1 (ABDD) plants that were backcrossed as females to the hexaploid recurrent parent. Stem rust-resistant BC1F1 plants from each Ae. tauschii donor source were used as males to generate BC2F1 mapping populations. Bulked segregant analysis of BC2F1 genotypes was performed using 70 SSR loci distributed across the D genome. Using this approach, stem rust resistance genes from both accessions were located on chromosome arm 1DS and mapped using SSR and EST-STS markers. An allelism test indicated the stem rust resistance gene transferred from PI 603225 is Sr33. Race specificity suggests the stem rust resistance gene transferred from TA1662 is unique and this gene has been temporarily designated SrTA1662. Stem rust resistance genes derived from TA1662 and PI 603225 have been made available with selectable molecular markers in genetic backgrounds suitable for stem rust resistance breeding. PMID:23377571

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

2013-05-01

104

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

PubMed Central

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.

Molnar, Istvan; Simkova, Hana; Leverington-Waite, Michelle; Goram, Richard; Cseh, Andras; Vrana, Jan; Farkas, Andras; Dolezel, Jaroslav; Molnar-Lang, Marta; Griffiths, Simon

2013-01-01

105

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

106

Whole-genome profiling and shotgun sequencing delivers an anchored, gene-decorated, physical map assembly of bread wheat chromosome 6A.  

PubMed

Bread wheat (Triticum aestivum L.) is the most important staple food crop for 35% of the world's population. International efforts are underway to facilitate an increase in wheat production, of which the International Wheat Genome Sequencing Consortium (IWGSC) plays an important role. As part of this effort, we have developed a sequence-based physical map of wheat chromosome 6A using whole-genome profiling (WGP(™) ). The bacterial artificial chromosome (BAC) contig assembly tools fingerprinted contig (fpc) and linear topological contig (ltc) were used and their contig assemblies were compared. A detailed investigation of the contigs structure revealed that ltc created a highly robust assembly compared with those formed by fpc. The ltc assemblies contained 1217 contigs for the short arm and 1113 contigs for the long arm, with an L50 of 1 Mb. To facilitate in silico anchoring, WGP(™) tags underlying BAC contigs were extended by wheat and wheat progenitor genome sequence information. Sequence data were used for in silico anchoring against genetic markers with known sequences, of which almost 79% of the physical map could be anchored. Moreover, the assigned sequence information led to the 'decoration' of the respective physical map with 3359 anchored genes. Thus, this robust and genetically anchored physical map will serve as a framework for the sequencing of wheat chromosome 6A, and is of immediate use for map-based isolation of agronomically important genes/quantitative trait loci located on this chromosome. PMID:24813060

Poursarebani, Naser; Nussbaumer, Thomas; Simková, Hana; Safá?, Jan; Witsenboer, Hanneke; van Oeveren, Jan; Doležel, Jaroslav; Mayer, Klaus F X; Stein, Nils; Schnurbusch, Thorsten

2014-07-01

107

Applications of Suits spectral model to wheat  

NASA Technical Reports Server (NTRS)

Canopy reflectance calculations for a spring type Mexican wheat, Penjamo, are compared with published data on Scout winter wheat. Good agreement exists between model calculations and experimental data in the spectral range, 500 nm to 750 nm, suggesting that the model parameters for wheat can be applied to different cultivars of wheat in the same growth stage. Wheat canopy reflectance is dependent upon surface soil type and this dependency is examined with the Suits' spectral model. In this particular growth stage wheat reflectance is shown to be nearly independent of soil reflectance in the visible wavelengths and progressively dependent at longer wavelengths in the infrared.

Chance, J. E.

1977-01-01

108

Co-ordinate regulation of cytokinin gene family members during flag leaf and reproductive development in wheat  

PubMed Central

Background As the global population continues to expand, increasing yield in bread wheat is of critical importance as 20% of the world’s food supply is sourced from this cereal. Several recent studies of the molecular basis of grain yield indicate that the cytokinins are a key factor in determining grain yield. In this study, cytokinin gene family members in bread wheat were isolated from four multigene families which regulate cytokinin synthesis and metabolism, the isopentenyl transferases (IPT), cytokinin oxidases (CKX), zeatin O-glucosyltransferases (ZOG), and ?-glucosidases (GLU). As bread wheat is hexaploid, each gene family is also likely to be represented on the A, B and D genomes. By using a novel strategy of qRT-PCR with locus-specific primers shared among the three homoeologues of each family member, detailed expression profiles are provided of family members of these multigene families expressed during leaf, spike and seed development. Results The expression patterns of individual members of the IPT, CKX, ZOG, and GLU multigene families in wheat are shown to be tissue- and developmentally-specific. For instance, TaIPT2 and TaCKX1 were the most highly expressed family members during early seed development, with relative expression levels of up to 90- and 900-fold higher, respectively, than those in the lowest expressed samples. The expression of two cis-ZOG genes was sharply increased in older leaves, while an extremely high mRNA level of TaGLU1-1 was detected in young leaves. Conclusions Key genes with tissue- and developmentally-specific expression have been identified which would be prime targets for genetic manipulation towards yield improvement in bread wheat breeding programmes, utilising TILLING and MAS strategies.

2012-01-01

109

Nucleotide diversity and molecular evolution of the WAG-2 gene in common wheat (Triticum aestivum L) and its relatives.  

PubMed

In this work, we examined the genetic diversity and evolution of the WAG-2 gene based on new WAG-2 alleles isolated from wheat and its relatives. Only single nucleotide polymorphisms (SNP) and no insertions and deletions (indels) were found in exon sequences of WAG-2 from different species. More SNPs and indels occurred in introns than in exons. For exons, exons+introns and introns, the nucleotide polymorphism ? decreased from diploid and tetraploid genotypes to hexaploid genotypes. This finding indicated that the diversity of WAG-2 in diploids was greater than in hexaploids because of the strong selection pressure on the latter. All dn/ds ratios were < 1.0, indicating that WAG-2 belongs to a conserved gene affected by negative selection. Thirty-nine of the 57 particular SNPs and eight of the 10 indels were detected in diploid species. The degree of divergence in intron length among WAG-2 clones and phylogenetic tree topology suggested the existence of three homoeologs in the A, B or D genome of common wheat. Wheat AG-like genes were divided into WAG-1 and WAG-2 clades. The latter clade contained WAG-2, OsMADS3 and ZMM2 genes, indicating functional homoeology among them. PMID:22215965

Wei, Shuhong; Peng, Zhengsong; Zhou, Yonghong; Yang, Zaijun; Wu, Kai; Ouyang, Zhongming

2011-10-01

110

Analysis of the bread wheat genome using whole-genome shotgun sequencing.  

PubMed

Bread wheat (Triticum aestivum) is a globally important crop, accounting for 20 per cent of the calories consumed by humans. Major efforts are underway worldwide to increase wheat production by extending genetic diversity and analysing key traits, and genomic resources can accelerate progress. But so far the very large size and polyploid complexity of the bread wheat genome have been substantial barriers to genome analysis. Here we report the sequencing of its large, 17-gigabase-pair, hexaploid genome using 454?pyrosequencing, and comparison of this with the sequences of diploid ancestral and progenitor genomes. We identified between 94,000 and 96,000 genes, and assigned two-thirds to the three component genomes (A, B and D) of hexaploid wheat. High-resolution synteny maps identified many small disruptions to conserved gene order. We show that the hexaploid genome is highly dynamic, with significant loss of gene family members on 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 resource for accelerating gene discovery and improving this major crop. PMID:23192148

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; Gill, Bikram; Kianian, Sharyar; Anderson, Olin; Kersey, Paul; Dvorak, Jan; McCombie, W Richard; Hall, Anthony; Mayer, Klaus F X; Edwards, Keith J; Bevan, Michael W; Hall, Neil

2012-11-29

111

Telencephalic progenitors maintain anteroposterior identities cell autonomously.  

PubMed

Grafting experiments have demonstrated that determination of anteroposterior (AP) identity is an early step in neural patterning that precedes dorsoventral (DV) specification [1,2]. These studies used pieces of tissue, however, rather than individual cells to address this question. It thus remains unclear whether the maintenance of AP identity is a cell-autonomous property or a result of signaling between cells within the grafted tissue. Previously, we and others [3-5] have used transplants of dissociated brain cells to show that individual telencephalic precursor cells can adopt host-specific DV identities when they integrate within novel regions of the telencephalon. We have now undertaken a set of transplantations during the same mid-neurogenic period used in the previous studies to assess the ability of telencephalic progenitors to integrate and differentiate into more posterior regions of the neuraxis. We observed that telencephalic progenitors were capable of integrating and migrating within different AP levels of the central nervous system (CNS). Despite this, we found that telencephalic progenitors that integrated within the diencephalon and the mesencephalon continued to express a telencephalic marker until adulthood. We speculate that during neurogenesis individual progenitors are determined in terms of their AP but not their DV identity. Hence, AP identity is maintained cell autonomously within individual progenitors. PMID:9742404

Na, E; McCarthy, M; Neyt, C; Lai, E; Fishell, G

1998-08-27

112

Ethanol production from mixtures of wheat straw and wheat meal  

PubMed Central

Background Bioethanol can be produced from sugar-rich, starch-rich (first generation; 1G) or lignocellulosic (second generation; 2G) raw materials. Integration of 2G ethanol with 1G could facilitate the introduction of the 2G technology. The capital cost per ton of fuel produced would be diminished and better utilization of the biomass can be achieved. It would, furthermore, decrease the energy demand of 2G ethanol production and also provide both 1G and 2G plants with heat and electricity. In the current study, steam-pretreated wheat straw (SPWS) was mixed with presaccharified wheat meal (PWM) and converted to ethanol in simultaneous saccharification and fermentation (SSF). Results Both the ethanol concentration and the ethanol yield increased with increasing amounts of PWM in mixtures with SPWS. The maximum ethanol yield (99% of the theoretical yield, based on the available C6 sugars) was obtained with a mixture of SPWS containing 2.5% water-insoluble solids (WIS) and PWM containing 2.5% WIS, resulting in an ethanol concentration of 56.5 g/L. This yield was higher than those obtained with SSF of either SPWS (68%) or PWM alone (91%). Conclusions Mixing wheat straw with wheat meal would be beneficial for both 1G and 2G ethanol production. However, increasing the proportion of WIS as wheat straw and the possibility of consuming the xylose fraction with a pentose-fermenting yeast should be further investigated.

2010-01-01

113

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

114

Role for compartmentalization in nephron progenitor differentiation  

PubMed Central

Embryonic nephron progenitor cells are segregated in molecularly distinct compartments of unknown function. Our study reveals an integral role for bone morphogenetic protein-SMAD in promoting transition of progenitors from the primitive Cbp/p300-interacting transactivator 1 expressing (CITED1+) compartment to the uniquely sine oculis-related homeobox 2 expressing (SIX2-only) compartment where they become inducible by wingless-type mouse mammary tumor virus integration site family member (WNT)/?-catenin signaling. Significantly, CITED1+ cells are refractory to WNT/?-catenin induction. We propose a model in which the primitive CITED1+ compartment is refractory to induction by WNT9b/?-catenin, ensuring maintenance of undifferentiated progenitor cells for future nephrogenesis. Bone morphogenetic protein 7-SMAD is then required for transition to a distinct compartment in which cells become inducible by WNT9b/?-catenin, allowing them to progress toward epithelialization.

Brown, Aaron C.; Muthukrishnan, Sree Deepthi; Guay, Justin A.; Adams, Derek C.; Schafer, Dillon A.; Fetting, Jennifer L.; Oxburgh, Leif

2013-01-01

115

p63 and Brg1 control developmentally regulated higher-order chromatin remodelling at the epidermal differentiation complex locus in epidermal progenitor cells  

PubMed Central

Chromatin structural states and their remodelling, including higher-order chromatin folding and three-dimensional (3D) genome organisation, play an important role in the control of gene expression. The role of 3D genome organisation in the control and execution of lineage-specific transcription programmes during the development and differentiation of multipotent stem cells into specialised cell types remains poorly understood. Here, we show that substantial remodelling of the higher-order chromatin structure of the epidermal differentiation complex (EDC), a keratinocyte lineage-specific gene locus on mouse chromosome 3, occurs during epidermal morphogenesis. During epidermal development, the locus relocates away from the nuclear periphery towards the nuclear interior into a compartment enriched in SC35-positive nuclear speckles. Relocation of the EDC locus occurs prior to the full activation of EDC genes involved in controlling terminal keratinocyte differentiation and is a lineage-specific, developmentally regulated event controlled by transcription factor p63, a master regulator of epidermal development. We also show that, in epidermal progenitor cells, p63 directly regulates the expression of the ATP-dependent chromatin remodeller Brg1, which binds to distinct domains within the EDC and is required for relocation of the EDC towards the nuclear interior. Furthermore, Brg1 also regulates gene expression within the EDC locus during epidermal morphogenesis. Thus, p63 and its direct target Brg1 play an essential role in remodelling the higher-order chromatin structure of the EDC and in the specific positioning of this locus within the landscape of the 3D nuclear space, as required for the efficient expression of EDC genes in epidermal progenitor cells during skin development.

Mardaryev, Andrei N.; Gdula, Michal R.; Yarker, Joanne L.; Emelianov, Vladimir N.; Poterlowicz, Krzysztof; Sharov, Andrey A.; Sharova, Tatyana Y.; Scarpa, Julie A.; Chambon, Pierre; Botchkarev, Vladimir A.; Fessing, Michael Y.

2014-01-01

116

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

117

Close Binary Progenitors of Hypernovae  

NASA Astrophysics Data System (ADS)

In this paper we propose a new plausible mechanism of supernova explosions specific to close binary systems. The starting point is the common envelope phase in the evolution of a binary consisting of a red super giant and a neutron star. As the neutron star spirals towards the center of its companion it spins up via disk accretion. Depending on the specific angular momentum of gas captured by the neutron star via the Bondi-Hoyle mechanism, it may reach millisecond periods either when it is still inside the common envelope or after it has merged with the companion core. The high accretion rate may result in strong differential rotation of the neutron star and generation of a magnetar-strength magnetic field. The magnetar wind can blow away the common envelope if its magnetic field is as strong as 1015 G, and can destroy the entire companion if it is as strong as 1016 G. The total explosion energy can be comparable to the rotational energy of a millisecond pulsar and reach 1052 erg. The result is an unusual type-II supernova with very high luminosity during the plateau phase, followed by a sharp drop in brightness and a steep light-curve tail. The remnant is either a solitary magnetar or a close binary involving a Wolf-Rayet star and a magnetar. When this Wolf-Rayet star explodes this will be a third supernovae explosion in the same binary. A particularly interesting version of the binary progenitor involves merger of a red super giant star with an ultra-compact companion, neutron star or black hole. In the case if a strong magnetic field is not generated on the surface of a neutron star then it will collapse to a black hole. After that we expect the formation of a very long-lived accretion disk around the black hole. The Blandford-Znajek driven jet from this black hole may drive not only hypernovae explosion but produce a bright X-ray transient event on a time scale of 104 s.

Barkov, Maxim V.

118

WHEAT KERNEL PHYSICAL PROPERTIES AND MILLING PROCESS  

Microsoft Academic Search

A b s t r a c t . Studies concerning the relations between wheat kernel physical properties and milling properties have been carried out since the beginning of the cereal processing industry. The aim of the present work was to show the application of the most important physical properties of wheat for the evaluation of wheat technological qua lity,

Dariusz Dziki; Janusz Laskowski

119

Mechanical modeling of wheat hardness and fragmentation  

Microsoft Academic Search

The mechanical origin of the wheat hardness used to classify wheat flours is an open issue. We propose a cohesive granular model of wheat endosperm involving a discrete phase composed of starch granules, a continuous phase representing the protein matrix, and pores. A lattice element method is employed to simulate the behavior of numerical samples with variable matrix volume fraction

Vincent Topin; Farhang Radjaï; Jean-Yves Delenne; Frédéric Mabille

2009-01-01

120

Financial Performance of Specialized Wheat Farms.  

National Technical Information Service (NTIS)

Specialized wheat farms--those with at least 50 percent of their production from wheat and with at least $40,000 in total production--fared worse in 1985 than other specialized crop farms. Specialized wheat farms had the lowest returns margin and return o...

M. Ahearn R. Dubman G. Hanson

1987-01-01

121

Wheat Marketing and its Efficiency in India  

Microsoft Academic Search

The study examines the marketing of wheat in India, focusing on the private marketing system, the marketing efficiency and quality. Wheat is now a major food staple in India, crucial to India’s food economy and security. With production reaching 70 to 75 million tons and a large demand, India’s wheat economy is the second largest in the world. The efficiency

Vasant P. Gandhi; Abraham Koshy

2006-01-01

122

Wheat Marketing and its Efficiency in India  

Microsoft Academic Search

The study examines the marketing of wheat in India, focusing on the private marketing system, the marketing efficiency and quality. Wheat is now a major food staple in India, crucial to India’s food economy and security. With production reaching 70 to 75 million tons and a large demand, India’s wheat economy is the second largest in the world. The efficiency

Vasant P Gandhi; Abraham Koshy

2007-01-01

123

Wheat functional genomics and engineering crop improvement  

PubMed Central

Genetic mapping and determination of the organization of the wheat genome are changing the wheat-breeding process. New initiatives to analyze the expressed portion of the wheat genome and structural analysis of the genomes of Arabidopsis and rice are increasing our knowledge of the genes that are linked to key agronomically important traits.

Francki, Michael; Appels, Rudi

2002-01-01

124

Heritable, De Novo Resistance to Leaf Rust and Other Novel Traits in Selfed Descendants of Wheat Responding to Inoculation with Wheat Streak Mosaic Virus  

PubMed Central

Stable resistance to infection with Wheat streak mosaic virus (WSMV) can be evolved de novo in selfing bread wheat lines subjected to cycles of WSMV inoculation and selection of best-performing plants or tillers. To learn whether this phenomenon might be applied to evolve resistance de novo to pathogens unrelated to WSMV, we examined the responses to leaf rust of succeeding generations of the rust- and WSMV-susceptible cultivar ‘Lakin’ following WSMV inoculation and derived rust-resistant sublines. After three cycles of the iterative protocol five plants, in contrast to all others, expressed resistance to leaf and stripe rust. A subset of descendant sublines of one of these, ‘R1’, heritably and uniformly expressed the new trait of resistance to leaf rust. Such sublines, into which no genes from a known source of resistance had been introgressed, conferred resistance to progeny of crosses with susceptible parents. The F1 populations produced from crosses between, respectively, susceptible and resistant ‘Lakin’ sublines 4-3-3 and 4-12-3 were not all uniform in their response to seedling inoculation with race TDBG. In seedling tests against TDBG and MKPS races the F2s from F1 populations that were uniformly resistant had 3?1 ratios of resistant to susceptible individuals but the F2s from susceptible F1 progenitors were uniformly susceptible. True-breeding lines derived from resistant individuals in F2 populations were resistant to natural stripe and leaf rust inoculum in the field, while the ‘Lakin’ progenitor was susceptible. The next generation of six of the ‘Lakin’-derived lines exhibited moderate to strong de novo resistance to stem rust races TPMK, QFCS and RKQQ in seedling tests while the ‘Lakin’ progenitor was susceptible. These apparently epigenetic effects in response to virus infection may help researchers fashion a new tool that expands the range of genetic resources already available in adapted germplasm.

Seifers, Dallas L.; Haber, Steve; Martin, Terry J.; McCallum, Brent D.

2014-01-01

125

Myocardial Regeneration by Exogenous and Endogenous Progenitor Cells  

PubMed Central

A problem in need of resolution concerns the origin of cardiac progenitor cells and the mechanisms by which these cells are preserved within the cardiac niches. This may be accomplished by migration of progenitor cells from the bone marrow to the myocardium. Alternatively, the progenitor cell compartment in the heart may be maintained by asymmetric division of resident cells. These two possibilities are not mutually exclusive and both exogenous and endogenous progenitor cells may contribute to cardiac homeostasis.

Leri, Annarosa; Hosoda, Toru; Rota, Marcello; Kajstura, Jan; Anversa, Piero

2008-01-01

126

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

127

Epithelial Progenitors in the Normal Human Mammary Gland  

Microsoft Academic Search

The human mammary gland is organized developmentally as a hierarchy of progenitor cells that become progressively restricted in their proliferative abilities and lineage options. Three types of human mammary epithelial cell progenitors are now identified. The first is thought to be a luminal-restricted progenitor; in vitro under conditions that support both luminal and myoepithelial cell differentiation, this cell produces clones

John Stingl; Afshin Raouf; Joanne T. Emerman; Connie J. Eaves

2005-01-01

128

Retinal stem\\/progenitor properties of iris pigment epithelial cells  

Microsoft Academic Search

Neural stem cells\\/progenitors that give rise to neurons and glia have been identified in different regions of the brain, including the embryonic retina and ciliary epithelium of the adult eye. Here, we first demonstrate the characterization of neural stem\\/progenitors in postnatal iris pigment epithelial (IPE) cells. Pure isolated IPE cells could form spheres that contained cells expressing retinal progenitor markers

Guangwei Sun; Maki Asami; Hiroshi Ohta; Jun Kosaka; Mitsuko Kosaka

2006-01-01

129

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

130

Fine mapping and epistatic interactions of the vernalization gene VRN-D4 in hexaploid wheat.  

PubMed

Wheat vernalization requirement is mainly controlled by the VRN1, VRN2, VRN3, and VRN4 genes. The first three have been cloned and have homoeologs in all three genomes. VRN4 has been found only in the D genome (VRN-D4) and has not been cloned. We constructed a high-density genetic map of the VRN-D4 region and mapped VRN-D4 within a 0.09 cM interval in the centromeric region of chromosome 5D. Using telocentric 5D chromosomes generated from the VRN-D4 donor Triple Dirk F, we determined that VRN-D4 is located on the short arm. The VRN-D4 candidate region is colinear with a 2.24 Mb region on Brachypodium distachyon chromosome 4, which includes 127 predicted genes. Ten of these genes have predicted roles in development but we detected no functional polymorphisms associated to VRN-D4. Two recombination events separated VRN-D4 from TaVIL-D1, the wheat homolog of Arabidopsis vernalization gene VIL1, confirming that this gene is not a candidate for VRN-D4. We detected significant interactions between VRN-D4 and other four genes controlling vernalization requirement (Vrn-A1, Vrn-B1, Vrn-D1, and Vrn-B3), which confirmed that VRN-D4 is part of the vernalization pathway and that it is either upstream or is part of the regulatory feedback loop involving VRN1, VRN2 and VRN3 genes. The precise mapping of VRN-D4 and the characterization of its interactions with other vernalization genes provide valuable information for the utilization of VRN-D4 in wheat improvement and for our current efforts to clone this vernalization gene. PMID:24213553

Kippes, Nestor; Zhu, Jie; Chen, Andrew; Vanzetti, Leonardo; Lukaszewski, Adam; Nishida, Hidetaka; Kato, Kenji; Dvorak, Jan; Dubcovsky, Jorge

2014-02-01

131

Wheat in the Mediterranean revisited - tetraploid wheat landraces assessed with elite bread wheat Single Nucleotide Polymorphism markers  

PubMed Central

Background Single Nucleotide Polymorphism (SNP) panels recently developed for the assessment of genetic diversity in wheat are primarily based on elite varieties, mostly those of bread wheat. The usefulness of such SNP panels for studying wheat evolution and domestication has not yet been fully explored and ascertainment bias issues can potentially affect their applicability when studying landraces and tetraploid ancestors of bread wheat. We here evaluate whether population structure and evolutionary history can be assessed in tetraploid landrace wheats using SNP markers previously developed for the analysis of elite cultivars of hexaploid wheat. Results We genotyped more than 100 tetraploid wheat landraces and wild emmer wheat accessions, some of which had previously been screened with SSR markers, for an existing SNP panel and obtained publically available genotypes for the same SNPs for hexaploid wheat varieties and landraces. Results showed that quantification of genetic diversity can be affected by ascertainment bias but that the effects of ascertainment bias can at least partly be alleviated by merging SNPs to haplotypes. Analyses of population structure and genetic differentiation show strong subdivision between the tetraploid wheat subspecies, except for durum and rivet that are not separable. A more detailed population structure of durum landraces could be obtained than with SSR markers. The results also suggest an emmer, rather than durum, ancestry of bread wheat and with gene flow from wild emmer. Conclusions SNP markers developed for elite cultivars show great potential for inferring population structure and can address evolutionary questions in landrace wheat. Issues of marker genome specificity and mapping need, however, to be addressed. Ascertainment bias does not seem to interfere with the ability of a SNP marker system developed for elite bread wheat accessions to detect population structure in other types of wheat.

2014-01-01

132

Local Group progenitors: Lyman Alpha bright?  

NASA Astrophysics Data System (ADS)

We present a novel approach of identifying the Milky Way (MW) and Andromeda (M31) progenitors that could be visible as Lyman Alpha emitters (LAEs) at z˜ 6: we couple a snapshot from the Constrained Local UniversE Simulations (CLUES) project, which successfully reproduces the MW and M31 galaxies situated in their correct environment, to a LAE model. Exploring intergalactic medium (IGM) ionization states ranging from an almost neutral to a fully ionized one, we find that including (excluding) the effects of clustered sources the first Local Group progenitor appears as a LAE for a neutral hydrogen fraction ? (?). This number increases to five progenitors each of the MW and M31 being visible as LAEs for ?; the contribution from clustered sources is crucial in making many of the progenitors visible in the Ly? for all the ionization states considered. The stellar mass of the Local Group LAEs ranges between 107.2 and 108 M?, the dust mass is between 104.6 and 105.1 M? and the colour excess E(B-V) = 0.03-0.048. We find that the number density of these LAEs is higher than that of general field LAEs (observed in cosmological volumes) by about two (one) orders of magnitude for ? (0.4). Detections of such high LAE number densities at z˜ 6 would be a clear signature of an overdense region that could evolve and resemble the Local Group volume at z= 0.

Dayal, Pratika; Libeskind, Noam I.

2012-01-01

133

Isolation of Adult Mouse Myogenic Progenitors  

Microsoft Academic Search

Skeletal muscle regeneration in adults is thought to occur through the action of myogenic satellite cells located in close association with mature muscle fibers; however, these precursor cells have not been prospectively isolated, and recent studies have suggested that additional muscle progenitors, including cells of bone marrow or hematopoietic origin, may exist. To clarify the origin(s) of adult myogenic cells,

Richard I. Sherwood; Julie L. Christensen; Irina M. Conboy; Michael J. Conboy; Thomas A. Rando; Irving L. Weissman; Amy J. Wagers

2004-01-01

134

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

135

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

136

Temporal identity transition from Purkinje cell progenitors to GABAergic interneuron progenitors in the cerebellum.  

PubMed

In the cerebellum, all GABAergic neurons are generated from the Ptf1a-expressing ventricular zone (Ptf1a domain). However, the machinery to produce different types of GABAergic neurons remains elusive. Here we show temporal regulation of distinct GABAergic neuron progenitors in the cerebellum. Within the Ptf1a domain at early stages, we find two subpopulations; dorsally and ventrally located progenitors that express Olig2 and Gsx1, respectively. Lineage tracing reveals the former are exclusively Purkinje cell progenitors (PCPs) and the latter Pax2-positive interneuron progenitors (PIPs). As development proceeds, PCPs gradually become PIPs starting from ventral to dorsal. In gain- and loss-of-function mutants for Gsx1 and Olig1/2, we observe abnormal transitioning from PCPs to PIPs at inappropriate developmental stages. Our findings suggest that the temporal identity transition of cerebellar GABAergic neuron progenitors from PCPs to PIPs is negatively regulated by Olig2 and positively by Gsx1, and contributes to understanding temporal control of neuronal progenitor identities. PMID:24535035

Seto, Yusuke; Nakatani, Tomoya; Masuyama, Norihisa; Taya, Shinichiro; Kumai, Minoru; Minaki, Yasuko; Hamaguchi, Akiko; Inoue, Yukiko U; Inoue, Takayoshi; Miyashita, Satoshi; Fujiyama, Tomoyuki; Yamada, Mayumi; Chapman, Heather; Campbell, Kenneth; Magnuson, Mark A; Wright, Christopher V; Kawaguchi, Yoshiya; Ikenaka, Kazuhiro; Takebayashi, Hirohide; Ishiwata, Shin'ichi; Ono, Yuichi; Hoshino, Mikio

2014-01-01

137

PCR assays for the identification of rare recombination types from VP1 to 3D genomic region of vaccine derived poliovirus strains.  

PubMed

Poliomyelitis has been effectively controlled by the use of inactivated poliovirus vaccine (IPV) or trivalent live attenuated oral poliovirus vaccine (OPV). Since 1964, the use of OPV in mass vaccinations has resulted in drastic reductions of the number of poliomyelitis cases caused by wild-type polioviruses. However, the characterization of OPV derivatives with increased neurovirulence, constituted a real problem with respect to OPV safety. Mutations at attenuating sites of the genome and recombination events between Sabin strains of the trivalent OPV vaccine have been correlated with the loss of the attenuated phenotype of OPV strains and the acquisition of traits characteristic of wild polioviruses. In consequence, early detection and characterization of recombinant evolved derivatives of vaccine strains is highly important. In this report, ten PCR assays are described which allow for the identification of rare recombination events located in VP1, 2A, 2C, 3A, 3C and 3D genomic regions and predominant recombination events located in 2C and 3D genomic regions of OPV derivatives. These assays could be readily implemented in diagnostics laboratories lacking sequencing facilities as a first approach for the early detection and characterization of recombinant OPV derivatives. PMID:24315968

Dimitriou, T G; Pliaka, V; Kyriakopoulou, Z; Ruether, I G A; Tsakogiannis, D; Fountoucidou, P; Gartzonika, C; Levidiotou-Stefanou, S; Markoulatos, P

2014-08-01

138

De Novo Transcriptome Assembly and Analyses of Gene Expression during Photomorphogenesis in Diploid Wheat Triticum monococcum  

PubMed Central

Background Triticum monococcum (2n) is a close ancestor of T. urartu, the A-genome progenitor of cultivated hexaploid wheat, and is therefore a useful model for the study of components regulating photomorphogenesis in diploid wheat. In order to develop genetic and genomic resources for such a study, we constructed genome-wide transcriptomes of two Triticum monococcum subspecies, the wild winter wheat T. monococcum ssp. aegilopoides (accession G3116) and the domesticated spring wheat T. monococcum ssp. monococcum (accession DV92) by generating de novo assemblies of RNA-Seq data derived from both etiolated and green seedlings. Principal Findings The de novo transcriptome assemblies of DV92 and G3116 represent 120,911 and 117,969 transcripts, respectively. We successfully mapped ?90% of these transcripts from each accession to barley and ?95% of the transcripts to T. urartu genomes. However, only ?77% transcripts mapped to the annotated barley genes and ?85% transcripts mapped to the annotated T. urartu genes. Differential gene expression analyses revealed 22% more light up-regulated and 35% more light down-regulated transcripts in the G3116 transcriptome compared to DV92. The DV92 and G3116 mRNA sequence reads aligned against the reference barley genome led to the identification of ?500,000 single nucleotide polymorphism (SNP) and ?22,000 simple sequence repeat (SSR) sites. Conclusions De novo transcriptome assemblies of two accessions of the diploid wheat T. monococcum provide new empirical transcriptome references for improving Triticeae genome annotations, and insights into transcriptional programming during photomorphogenesis. The SNP and SSR sites identified in our analysis provide additional resources for the development of molecular markers.

Naithani, Sushma; Sullivan, Chris; Preece, Justin; Tiwari, Vijay K.; Elser, Justin; Leonard, Jeffrey M.; Sage, Abigail; Gresham, Cathy; Kerhornou, Arnaud; Bolser, Dan; McCarthy, Fiona; Kersey, Paul; Lazo, Gerard R.; Jaiswal, Pankaj

2014-01-01

139

Alkylresorcinols in wheat and rye flour and bread  

Microsoft Academic Search

The alkylresorcinol (AR) content and relative homologue composition were determined in Norwegian flours and bread. The following average values for total AR content (?g\\/gdm) were found: wholegrain wheat flour available only to bakers (490) and to both consumers and bakers (710), refined wheat flour (36), wheat bran (3625), wholegrain spelt wheat flour (650), refined spelt wheat flour (80), wholegrain rye

Annica A. M. Andersson; Per Åman; Margareta Wandel; Wenche Frølich

2010-01-01

140

Aphid resistance in wheat varieties.  

PubMed

As an environmentally compatible alternative to the use of conventional insecticides to control cereal aphids, we have investigated the possibility to exploit natural resistance to insect pests in wheat varieties. We have tested a wide range of hexaploid (Triticum aestivum), tetraploid (T. durum) and diploid (T. boeoticum and T. monococcum) wheat lines for resistance to the bird cherry oat aphid (Rhopalosiphum padi). Lines tested included Russian wheat aphid (Diuraphis noxia), greenbug (Schizaphis graminum), hessian fly (Mayetiola destructor) and orange wheat blossom midge (Sitodiplosis mosellana) resistant varieties. Antixenosis and antibiosis were determined in the settling and fecundity tests respectively. Since hydroxamic acids (Hx), including the most generally active, 2,4-dihidroxy-7-methoxy-1,4-benzoxazin-3-one (DIMBOA), are biosynthesised in many cereal plants and are implicated in resistance against insects, leaf tissue was analysed for Hx and the glucosides from which they are produced. The hexaploid varieties, which contained relatively low levels of the DIMBOA glucoside, did not deter aphid feeding or reduce nymph production significantly. Reduced settlement and nymph production were recorded on the diploid varieties, but they contained no detectable level of the glucoside or the toxic aglucone. PMID:20218532

Elek, Henriett; Werner, Peter; Smart, Lesley; Gordon-Weeks, Ruth; Nádasy, Miklós; Pickett, John

2009-01-01

141

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

2012-02-01

142

Derivation of Myoepithelial Progenitor Cells from Bipotent Mammary Stem/Progenitor Cells  

PubMed Central

There is increasing evidence that breast and other cancers originate from and are maintained by a small fraction of stem/progenitor cells with self-renewal properties. Recent molecular profiling has identified six major subtypes of breast cancer: basal-like, ErbB2-overexpressing, normal breast epithelial-like, luminal A and B, and claudin-low subtypes. To help understand the relationship among mammary stem/progenitor cells and breast cancer subtypes, we have recently derived distinct hTERT-immortalized human mammary stem/progenitor cell lines: a K5+/K19? type, and a K5+/K19+ type. Under specific culture conditions, bipotent K5+/K19? stem/progenitor cells differentiated into stable clonal populations that were K5?/K19? and exhibit self-renewal and unipotent myoepithelial differentiation potential in contrast to the parental K5+/K19? cells which are bipotent. These K5?/K19? cells function as myoepithelial progenitor cells and constitutively express markers of an epithelial to mesenchymal transition (EMT) and show high invasive and migratory abilities. In addition, these cells express a microarray signature of claudin-low breast cancers. The EMT characteristics of an un-transformed unipotent mammary myoepithelial progenitor cells together with claudin-low signature suggests that the claudin-low breast cancer subtype may arise from myoepithelial lineage committed progenitors. Availability of immortal MPCs should allow a more definitive analysis of their potential to give rise to claudin-low breast cancer subtype and facilitate biological and molecular/biochemical studies of this disease.

Zhao, Xiangshan; Malhotra, Gautam K.; Band, Hamid; Band, Vimla

2012-01-01

143

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

144

Microchimerism, Dendritic Cell Progenitors and Transplantation Tolerance  

PubMed Central

The recent discovery of multilineage donor leukocyte microchimerism in allograft recipients up to three decades after organ transplantation implies the migration and survival of donor stem cells within the host. It has been postulated that in chimeric graft recipients, reciprocal modulation of immune responsiveness between donor and recipient leukocytes may lead, eventually, to the induction of mutual immunologic nonreactivity (tolerance). A prominent donor leukocyte, both in human organ transplant recipients and in animals, has invariably been the bone marrow-derived dendritic cell (DC). These cells have been classically perceived as the most potent antigen-presenting cells but evidence also exists for their tolerogenicity. The liver, despite its comparatively heavy leukocyte content, is the whole organ that is most capable of inducing tolerance. We have observed that DC progenitors propagated from normal mouse liver in response to GM-CSF express only low levels of major histocompatibility complex (MHC) class II antigen and little or no cell surface B7 family T cell costimulatory molecules. They fail to activate resting naive allogeneic T cells. When injected into normal allogeneic recipients, these DC progenitors migrate to T-dependent areas of host lymphoid tissue, where some at least upregulate cell surface MHC class II. These donor-derived cells persist indefinitely, recapitulating the behavior pattern of donor leukocytes after the successful transplantation of all whole organs, but most dramatically after the orthotopic (replacement) engraftment of the liver. A key finding is that in mice, progeny of these donor-derived DC progenitors can be propagated ex vivo from the bone marrow and other lymphoid tissues of nonimmunosuppressed spontaneously tolerant liver allograft recipients. In humans, donor DC can also be grown from the blood of organ allograft recipients whose organ-source chimerism is augmented with donor bone marrow infusion. DC progenitors cannot, however, be propagated from the lymphoid tissue of nonimmunosuppressed cardiac-allografted mice that reject their grafts. These findings are congruent with the possibility that bidirectional leukoeyte migration and donor cell chimerism play key roles in acquired transplantation tolerance. Although the cell interactions are undoubtedly complex, a discrete role can be identified for DC under well-defined experimental conditions. Bone marrow-derived DC progenitors (MHC class II+, B7-1dim, B7-2?) induce alloantigen-specific hyporesponsiveness (anergy) in naive T cells in vitro. Moreover, costimulatory molecule-deficient DC progenitors administered systemically prolong the survival of mouse heart or pancreatic islet allografts. How the regulation of donor DC phenotype and function relates to the balance between the immunogenicity and tolerogenicity of organ allografts remains to be determined.

Thomson, Angus W.; Lu, Lina; Murase, Noriko; Demetris, Anthony J.; Rao, Abdul S.; Starzl, Thomas E.

2010-01-01

145

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

146

Hematopoietic progenitor migration to the adult thymus  

PubMed Central

While most hematopoietic lineages develop in the bone marrow (BM), T cells uniquely complete their development in the specialized environment of the thymus. Hematopoietic stem cells with long-term self-renewal capacity are not present in the thymus. As a result, continuous T cell development requires that BM-derived progenitors be imported into the thymus throughout adult life. The process of thymic homing begins with the mobilization of progenitors out of the bone marrow, continues with their circulation in the bloodstream, and concludes with their settling in the thymus. This review will discuss each of these steps as they occur in the unirradiated and post-irradiation scenarios, focusing on the molecular mechanisms of regulation. Improved knowledge about these early steps in T cell generation may accelerate the development of new therapeutic options in patients with impaired T cell number or function.

Zlotoff, Daniel A.; Bhandoola, Avinash

2010-01-01

147

Study of wheat protein based materials  

NASA Astrophysics Data System (ADS)

Wheat gluten is a naturally occurring protein polymer. It is produced in abundance by the agricultural industry, is biodegradable and very inexpensive (less than $0.50/lb). It has unique viscoelastic properties, which makes it a promising alternative to synthetic plastics. The unplasticized wheat gluten is, however, brittle. Plasticizers such as glycerol are commonly used to give flexibility to the articles made of wheat gluten but with the penalty of greatly reduced stiffness. Former work showed that the brittleness of wheat gluten can also be improved by modifying it with a tri-thiol additive with no penalty of reduced stiffness. However, the cost of the customer designed tri-thiol additive was very high and it was unlikely to make a cost effective material from such an expensive additive. Here we designed a new, inexpensive thiol additive called SHPVA. It was synthesized from polyvinyl alcohol (PVA) through a simple esterification reaction. The mechanical data of the molded wheat gluten/SHPVA material indicated that wheat gluten was toughened by SHPVA. As a control, the wheat gluten/PVA material showed no improvement compared with wheat gluten itself. Several techniques have been used to characterize this novel protein/polymer blend. Differential scanning calorimetric (DSC) study showed two phases in both wheat gluten/PVA and wheat gluten/SHPVA material. However, scanning electron microscope (SEM) pictures indicated that PVA was macroscopically separated from wheat gluten, while wheat gluten/SHPVA had a homogeneous look. The phase image from the atomic force microscope (AFM) gave interesting contrast based on the difference in the mechanical properties of these two phases. The biodegradation behavior of these protein/polymer blends was examined in soil. SHPVA was not degraded in the time period of the experiment. Wheat gluten/SHPVA degraded slower than wheat gluten. We also developed some other interesting material systems based on wheat gluten, including the wheat gluten/basalt composite and wheat gluten/clay composite materials. Their mechanical properties and biodegradation behaviors were determined.

Ye, Peng

148

Allelic diversity associated with aridity gradient in wild emmer wheat populations.  

PubMed

The association between allelic diversity and ecogeographical variables was studied in natural populations of wild emmer wheat [Triticum turgidum ssp. dicoccoides (Körn.) Thell.], the tetraploid progenitor of cultivated wheat. Patterns of allelic diversity in 54 microsatellite loci were analyzed in a collection of 145 wild emmer wheat accessions representing 25 populations that were sampled across naturally occurring aridity gradient in Israel and surrounding regions. The obtained results revealed that 56% of the genetic variation resided among accessions within populations, while only 44% of the variation resided between populations. An unweighted pair-group method analysis (UPGMA) tree constructed based on the microsatellite allelic diversity divided the 25 populations into six major groups. Several groups were comprised of populations that were collected in ecologically similar but geographically remote habitats. Furthermore, genetic differentiation between populations was independent of the geographical distances. An interesting evolutionary phenomenon is highlighted by the unimodal relationship between allelic diversity and annual rainfall (r = 0.74, P < 0.0002), indicating higher allelic diversity in populations originated from habitats with intermediate environmental stress (i.e. rainfall 350-550 mm year(-1)). These results show for the first time that the 'intermediate-disturbance hypothesis', explaining biological diversity at the ecosystem level, also dominates the genetic diversity within a single species, the lowest hierarchical element of the biological diversity. PMID:17908203

Peleg, Zvi; Saranga, Yehoshua; Krugman, Tamar; Abbo, Shahal; Nevo, Eviatar; Fahima, Tzion

2008-01-01

149

Multipotent Progenitor Cells in Regenerative Cardiovascular Medicine  

Microsoft Academic Search

Regenerative therapies for heart diseases require the understanding of the molecular mechanisms that govern the fates and\\u000a differentiation of the diverse muscle and nonmuscle cell lineages that form during heart development. During mouse cardiogenesis,\\u000a the major lineages of the mature heart, cardiomyocytes, smooth muscle, endothelial cells, and cardiac mesenchyme, arise from\\u000a multipotent cardiovascular progenitors expressing the transcription factors Mesp1, Isl1,

Jason T. Lam; Alessandra Moretti; Karl-Ludwig Laugwitz

2009-01-01

150

Transcriptional Regulation of Heart Valve Progenitor Cells  

Microsoft Academic Search

The development and normal function of the heart valves requires complex interactions among signaling molecules, transcription\\u000a factors and structural proteins that are tightly regulated in time and space. Here we review the roles of critical transcription\\u000a factors that are required for specific aspects of normal valve development. The early progenitors of the heart valves are\\u000a localized in endocardial cushions that

Santanu Chakraborty; Michelle D. Combs; Katherine E. Yutzey

2010-01-01

151

Human marrow-derived mesenchymal progenitor cells  

Microsoft Academic Search

A number of adult mesenchymal tissues contain subpopulations of undifferentiated cells, which retain the capacity to differentiate\\u000a along multiple lineages. These mesenchymal progenitor cells may be cultured in an undifferentiated state and, when given the\\u000a appropriate signals, differentiate into an expanding list of several mesenchymal and a few ectodermal derived tissues. The\\u000a maintenance and propagation of the multipotential nature of

Edward J. Caterson; Leon J. Nesti; Keith G. Danielson; Rocky S. Tuan

2002-01-01

152

Molecular characterization of Haynaldia villosa chromatin in wheat lines carrying resistance to wheat curl mite colonization  

Microsoft Academic Search

Wheat-Haynaldia villosa (L.) Schur, hybrid lines were tested as potential sources of resistance to colonization by the wheat curl mite, the vector of wheat streak mosaic virus. Two lines, Add 6V-1 and Sub 6V-1, were found to be mite-resistant. Fluorescence in situ hybridization using total genomic DNA, from H. villosa in the presence of unlabelled wheat DNA, confirmed that Add

Q. Chen; R. L. Conner; A. Laroche

1996-01-01

153

Wheat Variety and Barley Malt Properties: Influence on Haze Intensity and Foam Stability of Wheat Beer  

Microsoft Academic Search

J. Inst. Brew. 110(3), 200-206, 2004 Laboratory wheat beers were brewed with different wheat va- rieties of different protein content (8.7-14.4%) and with five dif- ferent barley malts, varying in degree of modification (soluble protein: 3.9-6.9%). In a first series of experiments, it was in- vestigated whether wheat positively influences the foam stabil- ity, a major characteristic of wheat beers.

Sofie A. Depraetere; Filip Delvaux; Stefan Coghe; Freddy R. Delvaux

154

Constraining the Ages of Supernova Progenitors  

NASA Astrophysics Data System (ADS)

This thesis presents a study of the progenitor ages of Type Ia supernovae (SNe Ia) by measurement of positional age indicators in spiral host galaxies, using both quantitative analyses and qualitative comparison with SNe II, which are known to be young objects. Using our own images of over 220 SN host galaxies in the V and I filters, we examine three age indicators: distance from spiral arms, disk scale height, and background color. The distribution of SNe Ia around spiral arms is significantly broader than that of SNe II and more similar to the light from the general stellar population, indicating that the SNe Ia arise from progenitors old enough (at least 5 × 108 years) to have diffused away from their places of formation. An accurate measurement of the disk scale height of SNe is shown to be infeasible with the limited numbers of SNe detected in edge-on galaxies up to the present. The study of background colors of sites that have produced SNe shows much promise for age determination if additional factors such as accurate astrometry, aperture variation, and control apertures are taken into consideration. Our lower limit on the ages of SN Ia allows us to make distinctions among theoretical formation scenarios; we conclude that the most promising progenitor systems for SNe Ia may be coalescing white dwarf binaries.

McMillan, Russet Jennifer

155

EVOLUTION OF PROGENITORS FOR ELECTRON CAPTURE SUPERNOVAE  

SciTech Connect

We provide progenitor models for electron capture supernovae (ECSNe) with detailed evolutionary calculation. We include minor electron capture nuclei using a large nuclear reaction network with updated reaction rates. For electron capture, the Coulomb correction of rates is treated and the contribution from neutron-rich isotopes is taken into account in each nuclear statistical equilibrium (NSE) composition. We calculate the evolution of the most massive super asymptotic giant branch stars and show that these stars undergo off-center carbon burning and form ONe cores at the center. These cores become heavier up to the critical mass of 1.367 M{sub Sun} and keep contracting even after the initiation of O+Ne deflagration. Inclusion of minor electron capture nuclei causes convective URCA cooling during the contraction phase, but the effect on the progenitor evolution is small. On the other hand, electron capture by neutron-rich isotopes in the NSE region has a more significant effect. We discuss the uniqueness of the critical core mass for ECSNe and the effect of wind mass loss on the plausibility of our models for ECSN progenitors.

Takahashi, Koh; Umeda, Hideyuki [Department of Astronomy, University of Tokyo, Tokyo 113-0033 (Japan); Yoshida, Takashi, E-mail: ktakahashi@astron.s.u-tokyo.ac.jp, E-mail: umeda@astron.s.u-tokyo.ac.jp, E-mail: yoshida@yukawa.kyoto-u.ac.jp [Yukawa Institute for Theoretical Physics, Kyoto University, Kyoto 606-8502 (Japan)

2013-07-01

156

Intracellular Helicobacter pylori in gastric epithelial progenitors  

PubMed Central

Helicobacter pylori is generally viewed as an extracellular pathogen. We have analyzed the tropism of H. pylori clinical isolates in a gnotobiotic transgenic mouse model of human chronic atrophic gastritis, a preneoplastic condition. These mice lack acid-producing parietal cells and have an amplified population of dividing gastric epithelial progenitors (GEPs) that express NeuAc?2,3Gal?1,4-glycans recognized by H. pylori adhesins. Scanning confocal and transmission electron microscopic studies of stomachs that had been colonized for 1 month or 1 year revealed intracellular bacterial collections (IBCs) in a small subset of multi- and oligopotential epithelial progenitors. Transmission electron microscopic and multilabel immunohistochemical analyses disclosed bacteria with several morphotypes, including spiral-shaped, in the cytoplasm and endosomes. Several stages in IBC evolution were documented, from a few solitary bacteria to consolidated populations in dividing and nondividing GEPs, to microorganisms traversing breaches in the GEP plasma cell membrane. IBC formation was not a unique feature of H. pylori strains isolated from patients with chronic atrophic gastritis. The notion that adult mammalian epithelial progenitors can function as a repository for H. pylori broadens the view of host habitats available to this and perhaps other pathogens.

Oh, Jung D.; Karam, Sherif M.; Gordon, Jeffrey I.

2005-01-01

157

Constraints on the masses of supernova progenitors  

NASA Astrophysics Data System (ADS)

Star formation rates (SFR) for 175 nearby galaxies, derived from H-alpha emission data, are combined with the mean SN II rate to estimate the critical initial mass for a SN II progenitor. The best fitting SFR models, when combined with the observed SN II rate in face-on Sc galaxies, yield a lower limit mass for SN II progenitors of about 8 plus or minus 1 solar masses. A systematic underestimation of either the supernova rate or the Hubble constant used may lower this limit to 5-6 solar mases, but it is unlikely that the critical mass is lower than 5 or higher than 12 solar masses. The distribution of SN II in spiral arms of galaxies, and the low Galactic supernova rate, also suggest a mass limit of 8 plus or minus 3 solar masses. These limits are generally consistent with the recently determined progenitor masses of white dwarfs (Anthony-Twarog, 1982) and pulsars (Shipman and Green, 1980).

Kennicutt, R. C., Jr.

1984-02-01

158

Wheat grain tissue proportions in milling fractions using biochemical marker measurements: Application to different wheat cultivars  

Microsoft Academic Search

Measurement of biochemical markers allows the quantification of wheat (Triticum spp.) grain tissue proportions in milling fractions. In order to evaluate the ability of extending this methodology to an unknown wheat grain batch, the variability of the markers in the different tissues was assessed on various wheat cultivars. Ferulic acid trimer amounts in the outer pericarp ranged from 0.97 to

C. Barron; M. F. Samson; V. Lullien-Pellerin; X. Rouau

2011-01-01

159

Intrinsic karyotype stability and gene copy number variations may have laid the foundation for tetraploid wheat formation  

PubMed Central

Polyploidy or whole-genome duplication is recurrent in plant evolution, yet only a small fraction of whole-genome duplications has led to successful speciation. A major challenge in the establishment of nascent polyploids is sustained karyotype instability, which compromises fitness. The three putative diploid progenitors of bread wheat, with AA, SS (S ? B), and DD genomes occurred sympatrically, and their cross-fertilization in different combinations may have resulted in fertile allotetraploids with various genomic constitutions. However, only SSAA or closely related genome combinations have led to the speciation of tetraploid wheats like Triticum turgidum and Triticum timopheevii. We analyzed early generations of four newly synthesized allotetraploid wheats with genome compositions SshSshAmAm, SlSlAA, SbSbDD, and AADD by combined fluorescence and genomic in situ hybridization-based karyotyping. Results of karyotype analyses showed that although SshSshAmAm and SlSlAA are characterized by immediate and persistent karyotype stability, massive aneuploidy and extensive chromosome restructuring are associated with SbSbDD and AADD in which parental subgenomes showed markedly different propensities for chromosome gain/loss and rearrangements. Although compensating aneuploidy and reciprocal translocation between homeologs prevailed, reproductive fitness was substantially compromised due to chromosome instability. Strikingly, localized genomic changes in repetitive DNA and copy-number variations in gene homologs occurred in both chromosome stable lines, SshSshAmAm and SlSlAA. Our data demonstrated that immediate and persistent karyotype stability is intrinsic to newly formed allotetraploid wheat with genome combinations analogous to natural tetraploid wheats. This property, coupled with rapid gene copy-number variations, may have laid the foundation of tetraploid wheat establishment.

Zhang, Huakun; Bian, Yao; Gou, Xiaowan; Dong, Yuzhu; Rustgi, Sachin; Zhang, Bangjiao; Xu, Chunming; Li, Ning; Qi, Bao; Han, Fangpu; von Wettstein, Diter; Liu, Bao

2013-01-01

160

Intrinsic karyotype stability and gene copy number variations may have laid the foundation for tetraploid wheat formation.  

PubMed

Polyploidy or whole-genome duplication is recurrent in plant evolution, yet only a small fraction of whole-genome duplications has led to successful speciation. A major challenge in the establishment of nascent polyploids is sustained karyotype instability, which compromises fitness. The three putative diploid progenitors of bread wheat, with AA, SS (S ? B), and DD genomes occurred sympatrically, and their cross-fertilization in different combinations may have resulted in fertile allotetraploids with various genomic constitutions. However, only SSAA or closely related genome combinations have led to the speciation of tetraploid wheats like Triticum turgidum and Triticum timopheevii. We analyzed early generations of four newly synthesized allotetraploid wheats with genome compositions S(sh)S(sh)A(m)A(m), S(l)S(l)AA, S(b)S(b)DD, and AADD by combined fluorescence and genomic in situ hybridization-based karyotyping. Results of karyotype analyses showed that although S(sh)S(sh)A(m)A(m) and S(l)S(l)AA are characterized by immediate and persistent karyotype stability, massive aneuploidy and extensive chromosome restructuring are associated with S(b)S(b)DD and AADD in which parental subgenomes showed markedly different propensities for chromosome gain/loss and rearrangements. Although compensating aneuploidy and reciprocal translocation between homeologs prevailed, reproductive fitness was substantially compromised due to chromosome instability. Strikingly, localized genomic changes in repetitive DNA and copy-number variations in gene homologs occurred in both chromosome stable lines, S(sh)S(sh)A(m)A(m) and S(l)S(l)AA. Our data demonstrated that immediate and persistent karyotype stability is intrinsic to newly formed allotetraploid wheat with genome combinations analogous to natural tetraploid wheats. This property, coupled with rapid gene copy-number variations, may have laid the foundation of tetraploid wheat establishment. PMID:24218593

Zhang, Huakun; Bian, Yao; Gou, Xiaowan; Dong, Yuzhu; Rustgi, Sachin; Zhang, Bangjiao; Xu, Chunming; Li, Ning; Qi, Bao; Han, Fangpu; von Wettstein, Diter; Liu, Bao

2013-11-26

161

LACIE: Wheat yield models for the USSR  

NASA Technical Reports Server (NTRS)

A quantitative model determining the relationship between weather conditions and wheat yield in the U.S.S.R. was studied to provide early reliable forecasts on the size of the U.S.S.R. wheat harvest. Separate models are developed for spring wheat and for winter. Differences in yield potential and responses to stress conditions and cultural improvements necessitate models for each class.

Sakamoto, C. M.; Leduc, S. K.

1977-01-01

162

Breeding long coleoptile, reduced height wheats  

Microsoft Academic Search

Semidwarf wheats have the potential to produce high yields when sown and managed under optimal conditions. However, farm yields\\u000a often fall below this potential because of poor seedling establishment and low early vigour associated with gibberellic acid\\u000a (GA)-insensitive reducing-height ( Rht) genes contained in these wheats. Australian and overseas wheats containing major and\\u000a minor Rht genes sensitive to GA were

G. J. Rebetzke; R. A. Richards; V. M. Fischer; B. J. Mickelson

1999-01-01

163

Wheat breeding for end-product use  

Microsoft Academic Search

High grain yield is the primary objective of most wheat breeding programs around the world. In some countries, for example\\u000a Australia and Canada, a new wheat cultivar must meet a prescribed level of quality before it can be registered for commercial\\u000a production. For most traditional uses, wheat quality derives mainly from two interrelated characteristics: grain hardness\\u000a and protein content. Grain

W. Bushuk

1998-01-01

164

A Chromosome Bin Map of 16,000 Expressed Sequence Tag Loci and Distribution of Genes Among the Three Genomes of Polyploid Wheat  

PubMed Central

Because of the huge size of the common wheat (Triticum aestivum L., 2n = 6x = 42, AABBDD) genome of 17,300 Mb, sequencing and mapping of the expressed portion is a logical first step for gene discovery. Here we report mapping of 7104 expressed sequence tag (EST) unigenes by Southern hybridization into a chromosome bin map using a set of wheat aneuploids and deletion stocks. Each EST detected a mean of 4.8 restriction fragments and 2.8 loci. More loci were mapped in the B genome (5774) than in the A (5173) or D (5146) genomes. The EST density was significantly higher for the D genome than for the A or B. In general, EST density increased relative to the physical distance from the centromere. The majority of EST-dense regions are in the distal parts of chromosomes. Most of the agronomically important genes are located in EST-dense regions. The chromosome bin map of ESTs is a unique resource for SNP analysis, comparative mapping, structural and functional analysis, and polyploid evolution, as well as providing a framework for constructing a sequence-ready, BAC-contig map of the wheat genome.

Qi, L. L.; Echalier, B.; Chao, S.; Lazo, G. R.; Butler, G. E.; Anderson, O. D.; Akhunov, E. D.; Dvorak, J.; Linkiewicz, A. M.; Ratnasiri, A.; Dubcovsky, J.; Bermudez-Kandianis, C. E.; Greene, R. A.; Kantety, R.; La Rota, C. M.; Munkvold, J. D.; Sorrells, S. F.; Sorrells, M. E.; Dilbirligi, M.; Sidhu, D.; Erayman, M.; Randhawa, H. S.; Sandhu, D.; Bondareva, S. N.; Gill, K. S.; Mahmoud, A. A.; Ma, X.-F.; Miftahudin; Gustafson, J. P.; Conley, E. J.; Nduati, V.; Gonzalez-Hernandez, J. L.; Anderson, J. A.; Peng, J. H.; Lapitan, N. L. V.; Hossain, K. G.; Kalavacharla, V.; Kianian, S. F.; Pathan, M. S.; Zhang, D. S.; Nguyen, H. T.; Choi, D.-W.; Fenton, R. D.; Close, T. J.; McGuire, P. E.; Qualset, C. O.; Gill, B. S.

2004-01-01

165

Recurrent deletions of puroindoline genes at the grain hardness locus in four independent lineages of polyploid wheat.  

PubMed

Polyploidy is known to induce numerous genetic and epigenetic changes but little is known about their physiological bases. In wheat, grain texture is mainly determined by the Hardness (Ha) locus consisting of genes Puroindoline a (Pina) and b (Pinb). These genes are conserved in diploid progenitors but were deleted from the A and B genomes of tetraploid Triticum turgidum (AB). We now report the recurrent deletions of Pina-Pinb in other lineages of polyploid wheat. We analyzed the Ha haplotype structure in 90 diploid and 300 polyploid accessions of Triticum and Aegilops spp. Pin genes were conserved in all diploid species and deletion haplotypes were detected in all polyploid Triticum and most of the polyploid Aegilops spp. Two Pina-Pinb deletion haplotypes were found in hexaploid wheat (Triticum aestivum; ABD). Pina and Pinb were eliminated from the G genome, but maintained in the A genome of tetraploid Triticum timopheevii (AG). Subsequently, Pina and Pinb were deleted from the A genome but retained in the A(m) genome of hexaploid Triticum zhukovskyi (A(m)AG). Comparison of deletion breakpoints demonstrated that the Pina-Pinb deletion occurred independently and recurrently in the four polyploid wheat species. The implications of Pina-Pinb deletions for polyploid-driven evolution of gene and genome and its possible physiological significance are discussed. PMID:18024553

Li, Wanlong; Huang, Li; Gill, Bikram S

2008-01-01

166

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

2011-12-01

167

Marker-Assisted Selection for Recognizing Wheat Mutant Genotypes Carrying HMW Glutenin Alleles Related to Baking Quality  

PubMed Central

Allelic diversity of HMW glutenin loci in several studies revealed that allelic combinations affect dough quality. Dx5 + Dy10 subunits are related to good baking quality and Dx2 + Dy12 are related to undesirable baking quality. One of the most regular methods to evaluate the baking quality is SDS-PAGE which is used to improve baking quality labs. Marker-assisted selection is the method which can recognize the alleles related to baking quality and this method is based on polymerase chain reaction. 10 pairs of specific primers related to Dx2, Dx2.1, Dx5, Dy10, and Dy12 subunits were used for recognizing baking quality of some wheat varieties and some mutant genotypes. Only 5 pairs of them could show the specific bands. All subunits were recognized by the primers except Dx2.1. Some of the primers were extracted from previous studies and the others were designed based on D genome subunits of wheat. SDS-PAGE method accomplished having confidence in these marker's results. To realize the effect of mutation, seed storage proteins were measured. It showed that mutation had effect on the amount of seed storage protein on the mutant seeds (which showed polymorphism).

Zamani, Mohammad Javad; Bihamta, Mohammad Reza; Naserian Khiabani, Behnam; Tahernezhad, Zahra; Hallajian, Mohammad Taher; Shamsi, Marzieh Varasteh

2014-01-01

168

Structural Analysis of Wheat Stems  

Microsoft Academic Search

Design and development of improved harvesting, preprocessing, and bulk handling systems for biomass requires knowledge of\\u000a the biomechanical properties and structural characteristics of crop residue. Structural analysis of wheat stem cross-sections\\u000a was performed using the theory of composites and finite element analysis techniques. Representative geometries of the stem’s\\u000a structural components including the hypoderm, ground tissue, and vascular bundles were established

Kurt D. Hamman; Richard L. Williamson; Eric D. Steffler; Christopher T. Wright; J. Richard Hess; Peter A. Pryfogle

169

Structural analysis of wheat stems  

Microsoft Academic Search

Design and development of improved harvesting, preprocessing, and bulk handling systems for biomass requires knowledge of\\u000a the biomechanical properties and structural characteristics of crop residue. Structural analysis of wheat stem cross-sections\\u000a was performed using the theory of composites and finite element analysis techniques. Representative geometries of the stem’s\\u000a structural components including the hypoderm, ground tissue, and vascular bundles were established

Kurt D. Hamman; Richard L. Williamson; Eric D. Steffler; Christopher T. Wright; J. Richard Hess; Peter A. Pryfogle

2005-01-01

170

The progenitor of SN 2005cs in the Whirlpool Galaxy  

Microsoft Academic Search

The progenitor of SN 2005cs, in the galaxy M51, is identified in pre-explosion Hubble Space Telescope (HST) Advanced Camera for Surveys (ACS) Wide Field Channel (WFC) imaging. Differential astrometry, with post-explosion ACS High Resolution Channel (HRC) F555W images, permitted the identification of the progenitor with an accuracy of 0.006 arcsec. The progenitor was detected in the F814W pre-explosion image with

Justyn R. Maund; Stephen J. Smartt; I. John Danziger

2005-01-01

171

Response of Russian wheat aphid resistance in wheat and barley to four Diuraphis (Hemiptera: Aphididae) species.  

PubMed

Three Diuraphis species, Diuraphis frequens (Walker), Diuraphis mexicana (McVicar Baker), and Diuraphis tritici (Gillette), were known to exist in the United States before the 1986 appearance of the Russian wheat aphid, Diuraphis noxia Kurdjumov. The Russian wheat aphid soon became a significant pest of wheat although other endemic Diuraphis species were known to infest wheat. Wheat and barley entries resistant and susceptible to Russian wheat aphid biotype 2 were evaluated against all four Diuraphis species to determine their host interrelationships. Leaf chlorosis, leaf roll, leaf number, plant height, and infestation levels were assessed 21 d after the plants were infested by aphids in a no-choice caged environment. D. mexicana was unable to survive on wheat by 21 d after infestation and effects on the plant damage variables were negligible. D. frequens survived at low levels on resistant and susceptible plant entries and had a low impact on plant damage and growth. Russian wheat aphid biotype 2 and D. tritici were damaged most wheat and barley lines except the Russian wheat aphid biotype 2-resistant wheat lines containing genes from Dn7, STARS 2414-11, and CI2401; and resistant barley containing genes from STARS 9577B and 9301B. Russian wheat aphid biotype 2 and D. tritici reduced the growth of resistant plants by 25-50% and susceptible entries by 65-75%. Reductions at this level are typical under no-choice studies but resistant cultivars do not have these reductions under field conditions. The Russian wheat aphid biotype 2 resistant wheat lines would be effective in managing both wheat pest species. PMID:23786097

Puterka, Gary J; Scott, J Nicholson; Brown, Michael J; Hammon, R W

2013-04-01

172

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

2012-10-01

173

On the Progenitors of Long-GRBs and Hypernovae  

NASA Astrophysics Data System (ADS)

Identifying progenitor is important in understanding the origin and the properties of GRBs. However, there are still various possibilities to be the GRB progenitors. We first briefly review the models of Long-GRB progenitors and their uncertainties. Then we show our recent calculations about the massive star evolution with special attention to the metallicity dependent ambiguity of mass-loss rates. We discuss the conditions for single non-rotating stars to be a Type Ic supernovae, especially to be the progenitor of extremely bright Type Ic SN2007bi.

Umeda, Hideyuki; Yoshida, Takashi

2010-10-01

174

A unique wheat disease resistance-like gene governs effector-triggered susceptibility to necrotrophic pathogens.  

PubMed

Plant disease resistance is often conferred by genes with nucleotide binding site (NBS) and leucine-rich repeat (LRR) or serine/threonine protein kinase (S/TPK) domains. Much less is known about mechanisms of susceptibility, particularly to necrotrophic fungal pathogens. The pathogens that cause the diseases tan spot and Stagonospora nodorum blotch on wheat produce effectors (host-selective toxins) that induce susceptibility in wheat lines harboring corresponding toxin sensitivity genes. The effector ToxA is produced by both pathogens, and sensitivity to ToxA is governed by the Tsn1 gene on wheat chromosome arm 5BL. Here, we report the cloning of Tsn1, which was found to have disease resistance gene-like features, including S/TPK and NBS-LRR domains. Mutagenesis revealed that all three domains are required for ToxA sensitivity, and hence disease susceptibility. Tsn1 is unique to ToxA-sensitive genotypes, and insensitive genotypes are null. Sequencing and phylogenetic analysis indicated that Tsn1 arose in the B-genome diploid progenitor of polyploid wheat through a gene-fusion event that gave rise to its unique structure. Although Tsn1 is necessary to mediate ToxA recognition, yeast two-hybrid experiments suggested that the Tsn1 protein does not interact directly with ToxA. Tsn1 transcription is tightly regulated by the circadian clock and light, providing further evidence that Tsn1-ToxA interactions are associated with photosynthesis pathways. This work suggests that these necrotrophic pathogens may thrive by subverting the resistance mechanisms acquired by plants to combat other pathogens. PMID:20624958

Faris, Justin D; Zhang, Zengcui; Lu, Huangjun; Lu, Shunwen; Reddy, Leela; Cloutier, Sylvie; Fellers, John P; Meinhardt, Steven W; Rasmussen, Jack B; Xu, Steven S; Oliver, Richard P; Simons, Kristin J; Friesen, Timothy L

2010-07-27

175

A unique wheat disease resistance-like gene governs effector-triggered susceptibility to necrotrophic pathogens  

PubMed Central

Plant disease resistance is often conferred by genes with nucleotide binding site (NBS) and leucine-rich repeat (LRR) or serine/threonine protein kinase (S/TPK) domains. Much less is known about mechanisms of susceptibility, particularly to necrotrophic fungal pathogens. The pathogens that cause the diseases tan spot and Stagonospora nodorum blotch on wheat produce effectors (host-selective toxins) that induce susceptibility in wheat lines harboring corresponding toxin sensitivity genes. The effector ToxA is produced by both pathogens, and sensitivity to ToxA is governed by the Tsn1 gene on wheat chromosome arm 5BL. Here, we report the cloning of Tsn1, which was found to have disease resistance gene-like features, including S/TPK and NBS-LRR domains. Mutagenesis revealed that all three domains are required for ToxA sensitivity, and hence disease susceptibility. Tsn1 is unique to ToxA-sensitive genotypes, and insensitive genotypes are null. Sequencing and phylogenetic analysis indicated that Tsn1 arose in the B-genome diploid progenitor of polyploid wheat through a gene-fusion event that gave rise to its unique structure. Although Tsn1 is necessary to mediate ToxA recognition, yeast two-hybrid experiments suggested that the Tsn1 protein does not interact directly with ToxA. Tsn1 transcription is tightly regulated by the circadian clock and light, providing further evidence that Tsn1-ToxA interactions are associated with photosynthesis pathways. This work suggests that these necrotrophic pathogens may thrive by subverting the resistance mechanisms acquired by plants to combat other pathogens.

Faris, Justin D.; Zhang, Zengcui; Lu, Huangjun; Lu, Shunwen; Reddy, Leela; Cloutier, Sylvie; Fellers, John P.; Meinhardt, Steven W.; Rasmussen, Jack B.; Xu, Steven S.; Oliver, Richard P.; Simons, Kristin J.; Friesen, Timothy L.

2010-01-01

176

Modeling Leaf Production and Senescence in Wheat  

Microsoft Academic Search

4 Abstract: A major component in a crop growth model is leaf area development, which has a major influence on photosynthesis and transpiration. The knowledge about the leaf area development of wheat especially in high temperature environments is incomplete. The aim of this study was to quantify leaf production and senescence of 15 spring wheat cultivars. Field experiments were conducted

J. Pourreza; A. Soltani; A. Naderi; A. Aynehband

2009-01-01

177

Afghanistan's Wheat Flour Market: Policies and Prospects.  

National Technical Information Service (NTIS)

Afghanistan is among the worlds largest importers of fl our. Afghan fl our producers face challenges from inadequate domestic supplies of wheat and competition from imported fl our, much of it from neighboring Pakistan where wheat producers and fl our mil...

S. Persaud

2013-01-01

178

Wheat: Situation and Outlook Yearbook, March 2006.  

National Technical Information Service (NTIS)

U.S. 2006 wheat harvested area is projected down 1.4 million acres from 2005. Projected production is down 30 million bushels even though yields are projected up slightly from a year ago. Total U.S. wheat disappearance in 2006/07 is expected to decline by...

E. Allen G. Vocke

2006-01-01

179

Economic Effects of Standardizing Wheat Protein Reporting,  

National Technical Information Service (NTIS)

Wheat protein content has traditionally been reported on an 'as-is' moisture basis by the U.S. wheat trade. In an effort to provide inspection results which are easier to evaluate and compare, the Federal Grain Inspection Service (FGIS) began reporting pr...

L. A. Hoffman J. L. Harwood M. N. Leath

1988-01-01

180

Wheat: Situation and Outlook Yearbook, March 2003.  

National Technical Information Service (NTIS)

U.S. farmers boosted winter wheat seedings for 2003 to 44.2 million acres, the largest since 1998. Seedings are up 2.5 million acres from 2002 because of high prices during September and October when most of the winter wheat was planted. However, little c...

L. King M. Evans

2003-01-01

181

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

182

Progenitor endothelial cell involvement in Alzheimer's disease  

SciTech Connect

There is compelling evidence that endothelial cells of the brain and periphery are dysfunctional in Alzheimer's Disease. There is evidence for a fundamental defect in, or abnormal aging of, endothelial progenitor cells in atherosclerosis. The possibility that endothelial cell defects are a primary cause for Alzheimer's Disease or other dementias can be researched by molecular and cell biology studies as well as cell trafficking studies using recently demonstrated molecular imaging methods. The evidence for abnormal endothelial function and the methods to explore this hypothesis are presented.

Budinger, Thomas F.

2003-05-01

183

State-Level Wheat Statistics, 1949-88.  

National Technical Information Service (NTIS)

The bulletin provides State-level time series data on production levels and trends for all wheat, winter wheat, durum wheat, and other spring wheat for 1949-88. Table variables include area planted, area harvested, yield per harvested acre, quantity produ...

J. Langley S. Langley

1989-01-01

184

Progress Report for the Agricultural Research Foundation Oregon Wheat Commission  

Microsoft Academic Search

The OSU wheat quality program conducted wheat quality tests on grain collected from OSU elite variety trials harvested in 2004 and from hard-wheat nurseries harvested in 2005. The latter testing provided critical milling, kernel, and dough rheology data on 35 hard wheat lines so selection decisions could be made before replanting in the fall. For the 2004 harvested grain, comprehensive

Andrew Ross; J. Peterson; J. Ohm; M. Verhoeven; M. Larson; Craig Morris

185

Grain Hardness: A Major Determinant of Wheat Quality  

Microsoft Academic Search

Wheat quality, a complex term, depends upon intentional use for unambiguous products. The foremost determinants of wheat quality are endosperm texture (grain hardness), protein content and gluten strength. Endosperm texture in wheat is the single most important and defining quality characteristic, as it facilitates wheat classification and affects milling, baking and end-use quality. Various techniques used for grain hardness measurement

I. Pasha; F. M. Anjum; C. F. Morris

2010-01-01

186

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

187

Sequencing of chloroplast genomes from wheat, barley, rye and their relatives provides a detailed insight into the evolution of the Triticeae tribe.  

PubMed

Using Roche/454 technology, we sequenced the chloroplast genomes of 12 Triticeae species, including bread wheat, barley and rye, as well as the diploid progenitors and relatives of bread wheat Triticum urartu, Aegilops speltoides and Ae. tauschii. Two wild tetraploid taxa, Ae. cylindrica and Ae. geniculata, were also included. Additionally, we incorporated wild Einkorn wheat Triticum boeoticum and its domesticated form T. monococcum and two Hordeum spontaneum (wild barley) genotypes. Chloroplast genomes were used for overall sequence comparison, phylogenetic analysis and dating of divergence times. We estimate that barley diverged from rye and wheat approximately 8-9 million years ago (MYA). The genome donors of hexaploid wheat diverged between 2.1-2.9 MYA, while rye diverged from Triticum aestivum approximately 3-4 MYA, more recently than previously estimated. Interestingly, the A genome taxa T. boeoticum and T. urartu were estimated to have diverged approximately 570,000 years ago. As these two have a reproductive barrier, the divergence time estimate also provides an upper limit for the time required for the formation of a species boundary between the two. Furthermore, we conclusively show that the chloroplast genome of hexaploid wheat was contributed by the B genome donor and that this unknown species diverged from Ae. speltoides about 980,000 years ago. Additionally, sequence alignments identified a translocation of a chloroplast segment to the nuclear genome which is specific to the rye/wheat lineage. We propose the presented phylogeny and divergence time estimates as a reference framework for future studies on Triticeae. PMID:24614886

Middleton, Christopher P; Senerchia, Natacha; Stein, Nils; Akhunov, Eduard D; Keller, Beat; Wicker, Thomas; Kilian, Benjamin

2014-01-01

188

Estrogen and progesterone together expand murine endometrial epithelial progenitor cells  

PubMed Central

Synchronous with massive shifts in reproductive hormones, the uterus and its lining the endometrium expand to accommodate a growing fetus during pregnancy. In the absence of an embryo the endometrium, composed of epithelium and stroma, undergoes numerous hormonally regulated cycles of breakdown and regeneration. The hormonally mediated regenerative capacity of the endometrium suggests that signals that govern the growth of endometrial progenitors must be regulated by estrogen and progesterone. Here we report an antigenic profile for isolation of mouse endometrial epithelial progenitors. These cells are EpCAM+CD44+ITGA6hiThy1?PECAM1?PTPRC?Ter119?, comprise a minor subpopulation of total endometrial epithelia and possess a gene expression profile that is unique and different from other cells of the endometrium. The epithelial progenitors of the endometrium could regenerate in vivo, undergo multi-lineage differentiation and proliferate. We show that the number of endometrial epithelial progenitors is regulated by reproductive hormones. Co-administration of estrogen and progesterone dramatically expanded the endometrial epithelial progenitor cell pool. This effect was not observed when estrogen or progesterone was administered alone. Despite the remarkable sensitivity to hormonal signals, endometrial epithelial progenitors do not express estrogen or progesterone receptors. Therefore their hormonal regulation must be mediated through paracrine signals resulting from binding of steroid hormones to the progenitor cell niche. Discovery of signaling defects in endometrial epithelial progenitors or their niche can lead to development of better therapies in diseases of the endometrium.

Janzen, DM; Cheng, D; Schafenacker, AM; Paik, DY; Goldstein, AS; Witte, ON; Jaroszewicz, A; Pellegrini, M; Memarzadeh, S

2013-01-01

189

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 Calabrò; Paola Salvatore; Alfredo Ciccodicola; Claudio Napoli

2010-01-01

190

Radioprotection of hematopoietic progenitors by low dose amifostine prophylaxis.  

PubMed

Abstract Purpose: Amifostine is a highly efficacious cytoprotectant when administered in vivo at high doses. However, at elevated doses, drug toxicity manifests for general, non-clinical radioprotective purposes. Various strategies have been developed to avoid toxic side-effects: The simplest is reducing the dose. In terms of protecting hematopoietic tissues, where does this effective, non-toxic minimum dose lie? Material and methods: C3H/HEN mice were administered varying doses of amifostine (25-100 mg/kg) 30 min prior to cobalt-60 irradiation and euthanized between 4-14 days for blood and bone marrow collection and analyses. Results: Under steady-state, amifostine had little effect on bipotential and multi-potential marrow progenitors but marginally suppressed a more primitive, lineage negative progenitor subpopulation. In irradiated animals, prophylactic drug doses greater than 50 mg/kg resulted in significant regeneration of bipotential progenitors, moderate regeneration of multipotential progenitors, but no significant and consistent regeneration of more primitive progenitors. The low amifostine dose (25 mg/kg) failed to elicit consistent and positive, radioprotective actions on any of the progenitor subtypes. Conclusions: Radioprotective doses for amifostine appear to lie between 25 and 50 mg/kg. Mature, lineage-restricted progenitors appear to be more responsive to the protective effects of low doses of amifostine than the more primitive, multipotential progenitors. PMID:24597748

Seed, Thomas M; Inal, Cynthia E; Singh, Vijay K

2014-07-01

191

The Progenitor of SN 2005cs in the Whirlpool Galaxy  

Microsoft Academic Search

The progenitor of SN 2005cs, in the galaxy M51, is identified in\\u000apre-explosion HST ACS WFC imaging. Differential astrometry, with post-explosion\\u000aACS HRC F555W images, permitted the identification of the progenitor with an\\u000aaccuracy of 0.006\\

Justyn R. Maund; Stephen J. Smartt; I. John Danziger

2005-01-01

192

Identification of a B1 B cell–specified progenitor  

Microsoft Academic Search

The B-1 subpopulation of B lymphocytes differs phenotypically and functionally from conventional B-2 B cells. B-1 B cells are proposed to derive from a distinct progenitor, but such a population has not been isolated. Here we identify and characterize a B-1 B cell progenitor whose numbers peaked in fetal bone marrow but were less abundant in postnatal bone marrow. These

Encarnacion Montecino-Rodriguez; Hyosuk Leathers; Kenneth Dorshkind

2006-01-01

193

Estrogen and progesterone together expand murine endometrial epithelial progenitor cells.  

PubMed

Synchronous with massive shifts in reproductive hormones, the uterus and its lining the endometrium expand to accommodate a growing fetus during pregnancy. In the absence of an embryo the endometrium, composed of epithelium and stroma, undergoes numerous hormonally regulated cycles of breakdown and regeneration. The hormonally mediated regenerative capacity of the endometrium suggests that signals that govern the growth of endometrial progenitors must be regulated by estrogen and progesterone. Here, we report an antigenic profile for isolation of mouse endometrial epithelial progenitors. These cells are EpCAM(+) CD44(+) ITGA6(hi) Thy1(-) PECAM1(-) PTPRC(-) Ter119(-), comprise a minor subpopulation of total endometrial epithelia and possess a gene expression profile that is unique and different from other cells of the endometrium. The epithelial progenitors of the endometrium could regenerate in vivo, undergo multilineage differentiation and proliferate. We show that the number of endometrial epithelial progenitors is regulated by reproductive hormones. Coadministration of estrogen and progesterone dramatically expanded the endometrial epithelial progenitor cell pool. This effect was not observed when estrogen or progesterone was administered alone. Despite the remarkable sensitivity to hormonal signals, endometrial epithelial progenitors do not express estrogen or progesterone receptors. Therefore, their hormonal regulation must be mediated through paracrine signals resulting from binding of steroid hormones to the progenitor cell niche. Discovery of signaling defects in endometrial epithelial progenitors or their niche can lead to development of better therapies in diseases of the endometrium. PMID:23341289

Janzen, Deanna M; Cheng, Donghui; Schafenacker, Amanda M; Paik, Daniel Y; Goldstein, Andrew S; Witte, Owen N; Jaroszewicz, Artur; Pellegrini, Matteo; Memarzadeh, Sanaz

2013-04-01

194

Limiting mycotoxins in stored wheat.  

PubMed

The quality of harvested wheat grain can deteriorate markedly during the post-harvest management stages. Biotic factors, such as grain type and ripeness, coupled with the prevailing abiotic factors, such as water content and temperature, and also preservative concentration will influence the safe storage life and the level of contamination with mycotoxins. These mycotoxins include deoxynivalenol (DON) produced pre-harvest and zearalenone (ZEA) produced post-harvest by Fusarium graminearum and Fusarium poae, respectively, ochratoxin (OTA) produced by Penicillium verrucosum post-harvest in cool damp northern European climates, and perhaps T-2 and HT-2 toxins produced by Fusarium langsethiae. This review presents recent data on the relationship between dry matter losses caused by F. graminearum under different environmental regimes (water activities, temperatures) and the level of contamination with DON. This is important as poor post-harvest drying and storage management may exacerbate DON contamination already present pre-harvest. It is thus critical to relate the environmental factors in stored wheat grain during storage, especially of intergranular relative humidity (RH) and temperature, to safe storage periods without spoilage or risk from increased DON contamination. The growth/no growth and DON/no DON (F. graminearum) and OTA/no toxin production (P. verrucosum) have been used to build a model with a simple interface to link temperature and RH values to the potential risk level which may allow growth or toxin production. This paper also considers the use of modified atmospheres, preservatives and biocontrol to minimise DON and OTA in moist wheat grain. These approaches together with clear monitoring criteria and hygiene could contribute to better post-harvest management of stored temperate cereals and ensure that mycotoxin contamination is minimised during this key phase in the food/feed chain. PMID:20455159

Magan, Naresh; Aldred, David; Mylona, Kalliopi; Lambert, Ronald J W

2010-05-01

195

Endothelial Progenitor Cells Enter the Aging Arena  

PubMed Central

Age is a significant risk factor for the development of vascular diseases, such as atherosclerosis. Although pharmacological treatments, including statins and anti-hypertensive drugs, have improved the prognosis for patients with cardiovascular disease, it remains a leading cause of mortality in those aged 65?years and over. Furthermore, given the increased life expectancy of the population in developed countries, there is a clear need for alternative treatment strategies. Consequently, the relationship between aging and progenitor cell-mediated repair is of great interest. Endothelial progenitor cells (EPCs) play an integral role in the cellular repair mechanisms for endothelial regeneration and maintenance. However, EPCs are subject to age-associated changes that diminish their number in circulation and function, thereby enhancing vascular disease risk. A great deal of research is aimed at developing strategies to harness the regenerative capacity of these cells. In this review, we discuss the current understanding of the cells termed “EPCs,” examine the impact of age on EPC-mediated repair and identify therapeutic targets with potential for attenuating the age-related decline in vascular health via beneficial actions on EPCs.

Williamson, K.; Stringer, S. E.; Alexander, M. Y.

2012-01-01

196

HD 188112 - a candidate Supernova Ia progenitor  

NASA Astrophysics Data System (ADS)

Several different explosion channels have been proposed for Type IaSupernovae {SNe Ia}, and tested against observations throughhydrodynamic explosion simulations and radiative-transfercalculations. A promising scenario is the double detonation of asub-Chandrasekhar-mass C/O white dwarf {WD}, where a surfacedetonation in freshly accreted He subsequently triggers a detonationin the C/O core. The companion and He donor would likely be a low-massHe WD. Potential progenitor systems {i.e., binaries of a sufficientlymassive C/O WD with a low-mass He WD} have never been observed sofar. However, HD 188112 might be part of such a system. HD 188112 is anearby, bright, radial-velocity variable He WD of 0.24 M_?,whose unseen companion has been inferred to be another WD of at least0.73 M_?. The exact mass of the companion depends on the unknowninclination of the system. Assuming tidally locked rotation, theinclination can be determined measuring the broadening of metal linesdue to rotation. Since the metallicity of HD 188112 is extremely low{1/100 solar}, this measurement can only be performed in the UV,making the use of HST mandatory. If the mass of the companion ofHD 188112 is confirmed to be between 0.95 and 1.05 M_?, thefirst candidate double-detonation SN Ia progenitor system has beenfound.;

Heber, Ulrich

2011-07-01

197

Folate in wheat genotypes in the HEALTHGRAIN Diversity Screen.  

PubMed

As part of the diversity screen of the HEALTHGRAIN project, the total folate contents of bread wheat (130 winter and 20 spring wheat genotypes), durum wheat (10 genotypes), earlier cultivated diploid einkorn and tetraploid emmer wheat (5 genotypes of each), and spelt (5 genotypes), grown in the same location in a controlled manner, were determined by a microbiological assay. The total folate contents ranged from 364 to 774 ng/g of dm in winter wheat and from 323 to 741 ng/g of dm in spring wheat, thus showing a marked variation. The highest mean for total folate content was measured in the durum wheat genotypes, whereas the earlier cultivated diploid and tetraploid wheat genotypes and spelt were shown to possess comparable or even higher folate contents than bread wheat. HPLC analysis of selected genotypes showed that 5-formyltetrahydrofolate was the major vitamer. The data provide a basis for breeding wheat genotypes with improved folate content. PMID:18921972

Piironen, Vieno; Edelmann, Minnamari; Kariluoto, Susanna; Bedo, Zoltan

2008-11-12

198

Temporal Fate Specification and Neural Progenitor Competence During Development  

PubMed Central

The vast diversity of neurons and glia of the central nervous system is generated from a small, heterogeneous population of progenitors that undergo transcriptional changes during development to sequentially specify distinct cell fates. Guided by cell intrinsic and temporal extrinsic cues, invertebrate and mammalian neural progenitors carefully regulate when and how many of each cell type is produced to form functional neural circuits. Emerging evidence indicates that neural progenitors also undergo changes in global chromatin architecture, thereby restricting the duration a particular temporal cue can act. Thus, studies of temporal identity specification and progenitor competence can provide insight into how we may use neural progenitors to more effectively generate specific cell types for brain repair.

Kohwi, Minoree; Doe, Chris Q.

2014-01-01

199

White fat progenitor cells reside in the adipose vasculature.  

PubMed

White adipose (fat) tissues regulate metabolism, reproduction, and life span. Adipocytes form throughout life, with the most marked expansion of the lineage occurring during the postnatal period. Adipocytes develop in coordination with the vasculature, but the identity and location of white adipocyte progenitor cells in vivo are unknown. We used genetically marked mice to isolate proliferating and renewing adipogenic progenitors. We found that most adipocytes descend from a pool of these proliferating progenitors that are already committed, either prenatally or early in postnatal life. These progenitors reside in the mural cell compartment of the adipose vasculature, but not in the vasculature of other tissues. Thus, the adipose vasculature appears to function as a progenitor niche and may provide signals for adipocyte development. PMID:18801968

Tang, Wei; Zeve, Daniel; Suh, Jae Myoung; Bosnakovski, Darko; Kyba, Michael; Hammer, Robert E; Tallquist, Michelle D; Graff, Jonathan M

2008-10-24

200

Immortalization of epithelial progenitor cells mediated by resveratrol  

PubMed Central

Within the hierarchy of epithelial stem cells, normal progenitor cells may express regulated telomerase during renewal cycles of proliferation and differentiation. Dis-continuous telomerase activity may promote increased renewal capacity of progenitor cells, while deregulated/ continuous telomerase activity may promote immortalization when differentiation and/or senescent pathways are compromised. In the present work, we show that resveratrol activates, while progesterone inactivates, continuous telomerase activity within 24 h in subpopulations of human Li–Fraumeni syndrome-derived breast epithelial cells. Resveratrol results in immortalization of mixed progenitor cells with mutant p53, but not human epithelial cells with wild type p53. Our results demonstrate the potential for renewing progenitor cells with mutant p53 to immortalize after continuous telomerase expression when exposed to certain environmental compounds. Understanding the effects of telomerase modulators on endogenous telomerase activity in progenitor cells is relevant to the role of immortalization in the initiation and progression of cancer subtypes.

Pearce, VP; Sherrell, J; Lou, Z; Kopelovich, L; Wright, WE; Shay, JW

2012-01-01

201

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

202

Progress Report to the Agricultural Research Foundation Oregon Wheat Commission PROJECT: The Oregon Wheat Quality Evaluation Program PRINCIPLE INVESTIGATOR  

Microsoft Academic Search

$39,500 ABSTRACT: The overall goal of the OSU Wheat Quality Evaluation Program (OWQEP) is to provide high quality fundamental and applied research and service with respect to wheat quality. OWQEP activities underpin the quality improvement efforts of the OSU wheat breeding program, and the Oregon wheat industry. To date the OWQEP has provided a number of high impact outcomes. 1

Andrew S. Ross; C. James Peterson; Craig F. Morris; USDA ARS

203

Loss of SIMPL Compromises TNF? Dependent Survival of Hematopoietic Progenitors  

PubMed Central

Objective Emerging work has revealed an integral role of the TNF?-NF-?B pathway in the regulation of hematopoiesis. TNF? inhibition of hematopoietic stem/progenitor cell growth involves the type I TNF? receptor (TNF RI) and the type II TNF? receptor (TNF RII). However the role of TNF RI versus TNF RII in mediating this response is less clear. Full induction of NF-?B dependent gene expression through TNF RI requires the transcriptional co-activator SIMPL. To address the role of SIMPL in TNF? dependent signaling in hematopoiesis, endothelial cells and hematopoietic progenitors expressing SIMPL shRNA were characterized. Material and Methods In vitro gene expression and progenitor assays employing SIMPL shRNA were used to examine the requirement for SIMPL in TNF? dependent effects upon cytokine gene expression and hematopoietic progenitor cell growth. Competitive repopulation studies were used to extend these studies in vivo. Results SIMPL is required for full TNF RI dependent expression of NF-?B controlled cytokines in endothelial cells. Hematopoietic progenitor cell expansion is not affected if progenitors lacked SIMPL or if progenitors are treated with human TNF? which signals through TNF RI. In the absence of SIMPL, human TNF? leads to a dramatic decrease in progenitor cell expansion that is not due to apoptosis. Loss of SIMPL does not affect the activity of TGF-?1 and IFN?, other known suppressors of hematopoiesis. Conclusions The suppression of myeloid progenitor cell expansion requires signaling through TNF RI and TNF RII. Signals transduced through the TNF?-TNF RI-SIMPL pathway support hematopoietic progenitor cell survival, growth and differentiation.

Benson, Eric A.; Goebl, Mark G.; Yang, Feng-chun; Kapur, Reuben; McClintick, Jeanette; Sanghani, Sonal; Clapp, D. Wade; Harrington, Maureen A.

2009-01-01

204

Policosanol contents and compositions of wheat varieties.  

PubMed

Policosanol (PC) is the common name for a mixture of high molecular weight (20-36 carbon) aliphatic primary alcohols, which are constituents of plant epicuticular waxes. Wheat germ oil has been reported to improve human physical fitness, and this effect is attributed to its high PC, specifically its high octacosanol (OC) content. Although the PC composition of wheat leaves has been studied extensively, information on PC content and composition of wheat grain fractions is scarce. The objective of this study was to examine the PC contents and compositions of wheat grain fractions of 31 varieties grown in Oklahoma. PC compositions of the samples were identified using a gas chromatograph coupled with a mass spectrometer. The PC content of wheat bran was higher than that of the germ, shorts, and flour. The Trego and Intrada varieties had the highest PC content among the 31 wheat varieties studied. Tetracosanol (C24), hexacosanol (C26), and OC (C28) were the major PC components in all varieties. This study showed that wheat varieties grown under identical growing conditions and management differ significantly in PC content and composition. PMID:15998118

Irmak, Sibel; Dunford, Nurhan Turgut

2005-07-13

205

Endophytic establishment of Azorhizobium caulinodans in wheat  

PubMed Central

Nitrogen fixing nodules are formed on the roots and stems of the tropical legume Sesbania rostrata by Azorhizobium caulinodans as a result of crack entry invasion of emerging lateral roots. Advantage was taken of this invasion capability of A. caulinodans to determine whether inoculation of the non-legume wheat with A. caulinodans would result in the endophytic establishment of azorhizobia within wheat roots. Advantage was also taken of the oxygen tolerance of the nitrogenase of free-living azorhizobia to assess the extent to which the endophytic establishment of azorhizobia in wheat roots would provide a niche for nitrogen fixation of benefit to the plant. Wheat was inoculated with A. caulinodans and grown in pots under controlled conditions, without added growth reglators and without addition of fixed nitrogen. Microscopic examination of the short lateral roots of inocluated wheat showed invasion of azorhizobia between cells of the cortex, within the xylem and the root meristem Acetylene reduction assays combined with analysis of tissue nitrogen levels indicated the likelihood that colonization led to nitrogenase activity. Inoculated wheat showed significant increases in dry weight and nitrogen content as compared with uninoculated controls. We discuss the extent to which this nitrogen fixation is likely to involve symbiotic nitrogen fixation, and we indicate the need for field trials to determine the extent to which inolculation of wheat with A. caulinodans will reduce the requirement for inputs of nitrogenous fertilizers.

Sabry, S. R. S.; Saleh, S. A.; Batchelor, C. A.; Jones, J.; Jotham, J.; Webster, G.; Kothari, S. L.; Davey, M. R.; Cocking, E. C.

1997-01-01

206

Separability study of wheat and small grains  

NASA Technical Reports Server (NTRS)

The author has identified the following significant results. Barley showed significant separability from spring wheat, both multitemporally and on a single date chosen near the turning time for barley. Oats showed occasional multitemporal separability from barley and spring wheat; however, the cause of this separability was not well understood. Oats showed no significant separability from spring wheat on any single date during the growing season. By pooling data from segments having an acquisition near the turning time for barley, a fixed unitemporal projection for aiding in the labeling of barley versus spring wheat and oats was constructed. This projection has about the same separability of barley from spring wheat and oats as the unitemporal greeness versus brightness plot. The new fixed projection has the advantage that barley occurs consistently in the same general location on the plot with respect to spring wheat and oats. Attempts to construct a fixed multitemporal or a segment-dependent multitemporal projection for aiding in the labeling of spring wheat versus other small grains were unsuccessful due to segment availability and the fact that each segment has a unique acquisition history.

Lennington, R. K.; Marquina, N. E. (principal investigators)

1978-01-01

207

Marker-assisted selection of high molecular weight glutenin alleles related to bread-making quality in Iranian common wheat (Triticum aestivum L.).  

PubMed

Bread-making quality in hexaploid wheats is a complex trait. It has been shown that the amount and composition of protein can influence dough rheological properties. The high-molecular-weight (HMW) glutenins are encoded by a complex locus, Glu-1, on the long arm of group-1 homoeologus chromosome of the A, B and D genomes. In this work we used PCR-based DNA markers as a substitution tool to distinguish wheat bread-making quality. We detected PCR-based DNA markers for coding sequence of Glu-A1x, Glu-B1x and Glu-D1x to be 2300 bp, 2400 bp and 2500 bp respectively. DNA markers related to coding sequence of Glu-A1y, Glu-B1y and Glu-D1y were; 1800 bp, 2100 bp and 1950 bp, however, the repetitive region of their coding sequence were shown to be about 1300 bp, 1500 bp and 1600 bp. The results demonstrate that the size variation was due to different lengths of the central repetitive domain. Good or poor bread-making quality in wheat is associated with two allelic pairs of Glu-D1, designated 1Dx5-1Dy10 and 1Dx2-1Dy12. The 1Bx7 allele has moderate-to-good quality score. The specific DNA markers, of 450 bp, 576 bp, 612 bp and 2400 bp respectively were characterized for 1Dx5, 1Dy10, 1Dy12 and 1Bx7 alleles. These markers are very important in screening of wheat for bread-making quality. PMID:22942089

Izadi-Darbandi, Ali; Yazdi-Samadi, Bahman

2012-08-01

208

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

2013-08-01

209

Wheat production in controlled environments  

NASA Technical Reports Server (NTRS)

Conditions are optimized 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 a spacecraft. With yields of 23 to 57 g/sq m/d of edible biomass, a minimum size for a CELSS would be between 12 and 30 sq m per person, utilizing about 600 W/sq m of electrical energy for artificial light. Temperature, irradiance, photoperiod, carbon dioxide levels, humidity, and wind velocity are controlled in 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 sq m. Densities up to 2000 plants/sq m appear to increase seed yield. Biomass production increases almost linearily with increasing irradiance from 400 to 1700 micromol/sq m/s of photosynthetic photon flux, 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.

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

1987-01-01

210

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

PubMed

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. PMID:24065979

Fragasso, Mariagiovanna; Iannucci, Anna; Papa, Roberto

2013-01-01

211

Pannexin 1 regulates postnatal neural stem and progenitor cell proliferation  

PubMed Central

Background Pannexin 1 forms ion and metabolite permeable hexameric channels and is abundantly expressed in the brain. After discovering pannexin 1 expression in postnatal neural stem and progenitor cells we sought to elucidate its functional role in neuronal development. Results We detected pannexin 1 in neural stem and progenitor cells in vitro and in vivo. We manipulated pannexin 1 expression and activity in Neuro2a neuroblastoma cells and primary postnatal neurosphere cultures to demonstrate that pannexin 1 regulates neural stem and progenitor cell proliferation likely through the release of adenosine triphosphate (ATP). Conclusions Permeable to ATP, a potent autocrine/paracine signaling metabolite, pannexin 1 channels are ideally suited to influence the behavior of neural stem and progenitor cells. Here we demonstrate they play a robust role in the regulation of neural stem and progenitor cell proliferation. Endogenous postnatal neural stem and progenitor cells are crucial for normal brain health, and their numbers decline with age. Furthermore, these special cells are highly responsive to neurological injury and disease, and are gaining attention as putative targets for brain repair. Therefore, understanding the fundamental role of pannexin 1 channels in neural stem and progenitor cells is of critical importance for brain health and disease.

2012-01-01

212

In vivo fate mapping identifies mesenchymal progenitor cells.  

PubMed

Adult mesenchymal progenitor cells have enormous potential for use in regenerative medicine. However, the true identity of the progenitors in vivo and their progeny has not been precisely defined. We hypothesize that cells expressing a smooth muscle ?-actin promoter (?SMA)-directed Cre transgene represent mesenchymal progenitors of adult bone tissue. By combining complementary colors in combination with transgenes activating at mature stages of the lineage, we characterized the phenotype and confirmed the ability of isolated ?SMA(+) cells to progress from a progenitor to fully mature state. In vivo lineage tracing experiments using a new bone formation model confirmed the osteogenic phenotype of ?SMA(+) cells. In vitro analysis of the in vivo-labeled SMA9(+) cells supported their differentiation potential into mesenchymal lineages. Using a fracture-healing model, ?SMA9(+) cells served as a pool of fibrocartilage and skeletal progenitors. Confirmation of the transition of ?SMA9(+) progenitor cells to mature osteoblasts during fracture healing was assessed by activation of bone-specific Col2.3emd transgene. Our findings provide a novel in vivo identification of defined population of mesenchymal progenitor cells with active role in bone remodeling and regeneration. PMID:22083974

Grcevic, Danka; Pejda, Slavica; Matthews, Brya G; Repic, Dario; Wang, Liping; Li, Haitao; Kronenberg, Mark S; Jiang, Xi; Maye, Peter; Adams, Douglas J; Rowe, David W; Aguila, Hector L; Kalajzic, Ivo

2012-02-01

213

In vivo Fate Mapping identifies Mesenchymal Progenitor Cells  

PubMed Central

Adult mesenchymal progenitor cells have enormous potential for use in regenerative medicine. However, the true identity of the progenitors in vivo and their progeny has not been precisely defined. We hypothesize that cells expressing a smooth muscle ?-actin promoter (?SMA) directed Cre transgene represent mesenchymal progenitors of adult bone tissue. By combining complementary colors in combination with transgenes activating at mature stages of the lineage we characterized the phenotype and confirmed the ability of isolated ?SMA+ cells to progress from a progenitor to fully mature state. In vivo lineage tracing experiments using a new bone formation model confirmed the osteogenic phenotype of ?SMA+ cells. In vitro analysis of the in vivo labeled SMA9+ cells supported their differentiation potential into mesenchymal lineages. Utilizing a fracture-healing model, ?SMA+ cells served as a pool of fibrocartilage and skeletal progenitors. Confirmation of the transition of ?SMA+ progenitor cells to mature osteoblasts during fracture healing was assessed by activation of bone specific Col2.3emd transgene. Our findings provide a novel in vivo identification of defined population of mesenchymal progenitor cells with active role in bone remodeling and regeneration.

Grcevic, Danka; Pejda, Slavica; Matthews, Brya G.; Repic, Dario; Wang, Liping; Li, Haitao; Kronenberg, Mark S.; Jiang, Xi; Maye, Peter; Adams, Douglas J.; Rowe, David W.; Aguila, Hector L.; Kalajzic, Ivo

2013-01-01

214

Identification of functional progenitor cells in the pulmonary vasculature  

PubMed Central

The pulmonary vasculature comprises a complex network of branching arteries and veins all functioning to reoxygenate the blood for circulation around the body. The cell types of the pulmonary artery are able to respond to changes in oxygen tension in order to match ventilation to perfusion. Stem and progenitor cells in the pulmonary vasculature are also involved, be it in angiogenesis, endothelial dysfunction or formation of vascular lesions. Stem and progenitor cells may be circulating around the body, residing in the pulmonary artery wall or stimulated for release from a central niche like the bone marrow and home to the pulmonary vasculature along a chemotactic gradient. There may currently be some controversy over the pathogenic versus therapeutic roles of stem and progenitor cells and, indeed, it is likely both chains of evidence are correct due to the specific influence of the immediate environmental niche a progenitor cell may be in. Due to their great plasticity and a lack of specific markers for stem and progenitor cells, they can be difficult to precisely identify. This review discusses the methodological approaches used to validate the presence of and subtype of progenitors cells in the pulmonary vasculature while putting it in context of the current knowledge of the therapeutic and pathogenic roles for such progenitor cells.

Firth, Amy L.; Yuan, Jason X. -J.

2012-01-01

215

Genome-wide association for grain morphology in synthetic hexaploid wheats using digital imaging analysis  

PubMed Central

Background Grain size and shape greatly influence grain weight which ultimately enhances grain yield in wheat. Digital imaging (DI) based phenomic characterization can capture the three dimensional variation in grain size and shape than has hitherto been possible. In this study, we report the results from using digital imaging of grain size and shape to understand the relationship among different components of this trait, their contribution to enhance grain weight, and to identify genomic regions (QTLs) controlling grain morphology using genome wide association mapping with high density diversity array technology (DArT) and allele-specific markers. Results Significant positive correlations were observed between grain weight and grain size measurements such as grain length (r?=?0.43), width, thickness (r?=?0.64) and factor from density (FFD) (r?=?0.69). A total of 231 synthetic hexaploid wheats (SHWs) were grouped into five different sub-clusters by Bayesian structure analysis using unlinked DArT markers. Linkage disequilibrium (LD) decay was observed among DArT loci?>?10 cM distance and approximately 28% marker pairs were in significant LD. In total, 197 loci over 60 chromosomal regions and 79 loci over 31 chromosomal regions were associated with grain morphology by genome wide analysis using general linear model (GLM) and mixed linear model (MLM) approaches, respectively. They were mainly distributed on homoeologous group 2, 3, 6 and 7 chromosomes. Twenty eight marker-trait associations (MTAs) on the D genome chromosomes 2D, 3D and 6D may carry novel alleles with potential to enhance grain weight due to the use of untapped wild accessions of Aegilops tauschii. Statistical simulations showed that favorable alleles for thousand kernel weight (TKW), grain length, width and thickness have additive genetic effects. Allelic variations for known genes controlling grain size and weight, viz. TaCwi-2A, TaSus-2B, TaCKX6-3D and TaGw2-6A, were also associated with TKW, grain width and thickness. In silico functional analysis predicted a range of biological functions for 32 DArT loci and receptor like kinase, known to affect plant development, appeared to be common protein family encoded by several loci responsible for grain size and shape. Conclusion Conclusively, we demonstrated the application and integration of multiple approaches including high throughput phenotyping using DI, genome wide association studies (GWAS) and in silico functional analysis of candidate loci to analyze target traits, and identify candidate genomic regions underlying these traits. These approaches provided great opportunity to understand the breeding value of SHWs for improving grain weight and enhanced our deep understanding on molecular genetics of grain weight in wheat.

2014-01-01

216

Clara Cell: Progenitor for the Bronchiolar Epithelium  

PubMed Central

Clara cells were first described as a morphologically distinct cell type by Kolliker in 1881, but take their name from the seminal study of human and rabbit bronchioles by Max Clara in 1937. Since their discovery, Clara cells have been identified as central players in protecting the airway from environmental exposures. The diverse functions of Clara cells in lung homeostasis include roles in xenobiotic metabolism, immune system regulation, and progenitor cell activity. Recent identification of a sub-population of Clara cells as a bronchiolar tissue-specific stem cell and a potential tumor initiating cell has focused the attention of cell and molecular biologists on the Clara cell and its behavior under normal and disease conditions.

Reynolds, Susan D.; Malkinson, Alvin M.

2009-01-01

217

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

218

Cardiogenic potential of endothelial progenitor cells.  

PubMed

Transplantation of endothelial progenitor cells (EPCs) are one of the promising strategies to recover the capillary flow in ischaemic diseases such as ischaemic heart disease and peripheral artery disease (PAD) in the leg. However, our previous and another group's works suggested the scarcity of the number of EPCs in peripheral blood might cause insufficient effect for the ischaemic diseases. There are several strategies to overcome this issue, such as (1) in vivo EPC expansion; (2) ex vivo EPC expansion; (3) local (not systemic) EPC injection; and (4) modification of EPC by gene transfer. Recent publications from our own and other groups have reported the possibility of cardiogenic potential of EPCs. We would like to focus on the strategies of EPC transplantation and cardiomyogenesis of EPCs in this review. PMID:19124432

Murasawa, Satoshi; Asahara, Takayuki

2008-10-01

219

Cosmological black holes as voids progenitors: simulations  

NASA Astrophysics Data System (ADS)

Cosmological black holes (CBH), i.e. black holes with masses of the order of 10^{13}div 10^{14} M_{odot} , have been proposed as possible progenitors of galaxy voids. The presence of a CBH in the central region of a void should induce significant gravitational lensing effects and in this paper we discuss such gravitational signatures using simulated data. These signatures may be summarized as follows: (1) a blind spot in the projected position of the CBH where no objects can be detected; (2) an excess of faint secondary images; (3) an excess of double images having a characteristic angular separation. All these signatures are shown to be detectable in future deep surveys.

Serpico, M.; D'Abrusco, R.; Longo, G.; Stornaiolo, C.

2007-10-01

220

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.

221

Thyroid hormone accelerates the differentiation of adult hippocampal progenitors.  

PubMed

Disrupted thyroid hormone function evokes severe physiological consequences in the immature brain. In adulthood, although clinical reports document an effect of thyroid hormone status on mood and cognition, the molecular and cellular changes underlying these behavioural effects are poorly understood. More recently, the subtle effects of thyroid hormone on structural plasticity in the mature brain, in particular on adult hippocampal neurogenesis, have come to be appreciated. However, the specific stages of adult hippocampal progenitor development that are sensitive to thyroid hormone are not defined. Using nestin-green fluorescent protein reporter mice, we demonstrate that thyroid hormone mediates its effects on hippocampal neurogenesis by influencing Type 2b and Type 3 progenitors, although it does not alter proliferation of either the Type 1 quiescent progenitor or the Type 2a amplifying neural progenitor. Thyroid hormone increases the number of doublecortin (DCX)-positive Type 3 progenitors, and accelerates neuronal differentiation into both DCX-positive immature neurones and neuronal nuclei-positive granule cell neurones. Furthermore, we show that this increase in neuronal differentiation is accompanied by a significant induction of specific transcription factors involved in hippocampal progenitor differentiation. In vitro studies using the neurosphere assay support a direct effect of thyroid hormone on progenitor development because neurospheres treated with thyroid hormone are shifted to a more differentiated state. Taken together, our results indicate that thyroid hormone mediates its neurogenic effects via targeting Type 2b and Type 3 hippocampal progenitors, and suggests a role for proneural transcription factors in contributing to the effects of thyroid hormone on neuronal differentiation of adult hippocampal progenitors. PMID:22497336

Kapoor, R; Desouza, L A; Nanavaty, I N; Kernie, S G; Vaidya, V A

2012-09-01

222

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

223

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

224

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

225

Liver sinusoidal endothelial cell progenitor cells promote liver regeneration in rats  

PubMed Central

The ability of the liver to regenerate is crucial to protect liver function after injury and during chronic disease. Increases in hepatocyte growth factor (HGF) in liver sinusoidal endothelial cells (LSECs) are thought to drive liver regeneration. However, in contrast to endothelial progenitor cells, mature LSECs express little HGF. Therefore, we sought to establish in rats whether liver injury causes BM LSEC progenitor cells to engraft in the liver and provide increased levels of HGF and to examine the relative contribution of resident and BM LSEC progenitors. LSEC label-retaining cells and progenitors were identified in liver and LSEC progenitors in BM. BM LSEC progenitors did not contribute to normal LSEC turnover in the liver. However, after partial hepatectomy, BM LSEC progenitor proliferation and mobilization to the circulation doubled. In the liver, one-quarter of the LSECs were BM derived, and BM LSEC progenitors differentiated into fenestrated LSECs. When irradiated rats underwent partial hepatectomy, liver regeneration was compromised, but infusion of LSEC progenitors rescued the defect. Further analysis revealed that BM LSEC progenitors expressed substantially more HGF and were more proliferative than resident LSEC progenitors after partial hepatectomy. Resident LSEC progenitors within their niche may play a smaller role in recovery from partial hepatectomy than BM LSEC progenitors, but, when infused after injury, these progenitors engrafted and expanded markedly over a 2-month period. In conclusion, LSEC progenitor cells are present in liver and BM, and recruitment of BM LSEC progenitors is necessary for normal liver regeneration.

Wang, Lin; Wang, Xiangdong; Xie, Guanhua; Wang, Lei; Hill, Colin K.; DeLeve, Laurie D.

2012-01-01

226

Vascular Smooth Muscle Progenitor Cells: Building and Repairing Blood Vessels  

PubMed Central

Molecular pathways that control the specification, migration, and number of available smooth muscle progenitor cells play key roles in determining blood vessel size and structure, capacity for tissue repair and remodeling, and progression of age-related disorders. Defects in these pathways will produce malformations of developing blood vessels, depletion of SMC progenitor pools for vessel wall maintenance and repair, and aberrant activation of alternative differentiation pathways in vascular disease. A better understanding of the molecular mechanisms that uniquely specify and maintain vascular SMC precursors is essential if we are to utilize advances in stem and progenitor cell biology and somatic cell reprogramming for applications directed to the vessel wall.

Majesky, Mark W.; Dong, Xiu Rong; Regan, Jenna N.; Hoglund, Virginia J.

2011-01-01

227

New Results from the Supernova Ia Progenitor Survey  

NASA Astrophysics Data System (ADS)

We report on a systematic radial velocity survey for double degenerate (DD) binaries as potential progenitors of type Ia supernovae: SPY (ESO Supernovae Ia Progenitor surveY). More than 1000 white dwarfs and pre-white dwarfs were observed with the VLT. Our aim is to perform a statistically significant test of the DD scenario. SPY detected more than 100 new binary white dwarfs, dramatically increasing the number of known DDs. System parameters are determined from ongoing follow-up observations. Our sample includes systems with masses close to the Chandrasekhar limit and a probable SN Ia progenitor candidate.

Napiwotzki, R.; Karl, C. A.; Nelemans, G.; Yungelson, L.; Christlieb, N.; Drechsel, H.; Heber, U.; Homeier, D.; Koester, D.; Kruk, J.; Leibundgut, B.; Marsh, T. R.; Moehler, S.; Renzini, A.; Reimers, D.

2005-07-01

228

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

229

Paint removal using wheat starch blast media  

NASA Astrophysics Data System (ADS)

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 cracks confirms better crack visibility with wheat starch media versus Type V or Type II plastic media. Testing of wheat starch media in several composite test programs, including fiberglass, Kevlar, and graphite-epoxy composites, showed no fiber damage. Process developments and production experience at the first U.S. aircraft stripping facility are also reviewed. Corporate and regional aircraft are being stripped in this three nozzle dry blast hanger.

Foster, Terry; Oestreich, John

1993-03-01

230

Wheat domestication: lessons for the future.  

PubMed

Wheat was one of the first crops to be domesticated more than 10,000 years ago in the Middle East. Molecular genetics and archaeological data have allowed the reconstruction of plausible domestication scenarios leading to modern cultivars. For diploid einkorn and tetraploid durum wheat, a single domestication event has likely occurred in the Karacadag Mountains, Turkey. Following a cross between tetraploid durum and diploid T. tauschii, the resultant hexaploid bread wheat was domesticated and disseminated around the Caucasian region. These polyploidisation events facilitated wheat domestication and created genetic bottlenecks, which excluded potentially adaptive alleles. With the urgent need to accelerate genetic progress to confront the challenges of climate change and sustainable agriculture, wild ancestors and old landraces represent a reservoir of underexploited genetic diversity that may be utilized through modern breeding methods. Understanding domestication processes may thus help identifying new strategies. PMID:21377616

Charmet, Gilles

2011-03-01

231

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

232

Chromosome arm-specific BAC end sequences permit comparative analysis of homoeologous chromosomes and genomes of polyploid wheat  

PubMed Central

Background Bread wheat, one of the world’s staple food crops, has the largest, highly repetitive and polyploid genome among the cereal crops. The wheat genome holds the key to crop genetic improvement against challenges such as climate change, environmental degradation, and water scarcity. To unravel the complex wheat genome, the International Wheat Genome Sequencing Consortium (IWGSC) is pursuing a chromosome- and chromosome arm-based approach to physical mapping and sequencing. Here we report on the use of a BAC library made from flow-sorted telosomic chromosome 3A short arm (t3AS) for marker development and analysis of sequence composition and comparative evolution of homoeologous genomes of hexaploid wheat. Results The end-sequencing of 9,984 random BACs from a chromosome arm 3AS-specific library (TaaCsp3AShA) generated 11,014,359?bp of high quality sequence from 17,591 BAC-ends with an average length of 626?bp. The sequence represents 3.2% of t3AS with an average DNA sequence read every 19?kb. Overall, 79% of the sequence consisted of repetitive elements, 1.38% as coding regions (estimated 2,850 genes) and another 19% of unknown origin. Comparative sequence analysis suggested that 70-77% of the genes present in both 3A and 3B were syntenic with model species. Among the transposable elements, gypsy/sabrina (12.4%) was the most abundant repeat and was significantly more frequent in 3A compared to homoeologous chromosome 3B. Twenty novel repetitive sequences were also identified using de novo repeat identification. BESs were screened to identify simple sequence repeats (SSR) and transposable element junctions. A total of 1,057 SSRs were identified with a density of one per 10.4?kb, and 7,928 junctions between transposable elements (TE) and other sequences were identified with a density of one per 1.39?kb. With the objective of enhancing the marker density of chromosome 3AS, oligonucleotide primers were successfully designed from 758 SSRs and 695 Insertion Site Based Polymorphisms (ISBPs). Of the 96 ISBP primer pairs tested, 28 (29%) were 3A-specific and compared to 17 (18%) for 96 SSRs. Conclusion This work reports on the use of wheat chromosome arm 3AS-specific BAC library for the targeted generation of sequence data from a particular region of the huge genome of wheat. A large quantity of sequences were generated from the A genome of hexaploid wheat for comparative genome analysis with homoeologous B and D genomes and other model grass genomes. Hundreds of molecular markers were developed from the 3AS arm-specific sequences; these and other sequences will be useful in gene discovery and physical mapping.

2012-01-01

233

Natural variation for fertile triploid F1 hybrid formation in allohexaploid wheat speciation.  

PubMed

The tempo, mode, and geography of allopolyploid speciation are influenced by natural variation in the ability of parental species to express postzygotic reproductive phenotypes that affect hybrid fertility. To shed light on the impact of such natural variations, we used allohexaploid Triticum aestivum wheats' evolution as a model and analyzed the geographic and phylogenetic distributions of Aegilops tauschii (diploid progenitor) accessions involved in the expression of abnormality and fertility in triploid F(1) hybrids with Triticum turgidum (tetraploid progenitor). Artificial-cross experiments and chloroplast-DNA-based evolutionary analyses showed that hybrid-abnormality-causing accessions had limited geographic and phylogenetic distributions, indicative that postzygotic hybridization barriers are underdeveloped between these species. In contrast, accessions that are involved with fertile triploid F(1) hybrid formation have wide geographic and phylogenetic distributions, indicative of a deep evolutionary origin. Wide-spread hybrid-fertilizing accessions support the theory that T. aestivum speciation occurred at multiple sites within the species range of Ae. tauschii, in which existing conditions enabled natural hybridization with T. turgidum. Implications of our findings on how natural variation in the ability of Ae. tauschii to express those postzygotic reproductive phenotypes diversified and contributed to the speciation of T. aestivum are discussed. PMID:17639301

Matsuoka, Yoshihiro; Takumi, Shigeo; Kawahara, Taihachi

2007-08-01

234

Expansins and coleoptile elongation in wheat.  

PubMed

Expansins are now generally accepted to be the key regulators of wall extension during plant growth. The aim of this study was to characterize expansins in wheat coleoptiles and determine their roles in regulating cell growth. Endogenous and reconstituted wall extension activities of wheat coleoptiles were measured. The identification of beta-expansins was confirmed on the basis of expansin activity, immunoblot analysis, and beta-expansin inhibition. Expansin activities of wheat coleoptiles were shown to be sensitive to pH and a number of exogenously applied factors, and their optimum pH range was found to be 4.0 to 4.5, close to that of alpha-expansins. They were induced by dithiothreitol, K(+), and Mg(2+), but inhibited by Zn(2+), Cu(2+), Al(3+), and Ca(2+), similar to those found in cucumber hypocotyls. An expansin antibody raised against TaEXPB23, a vegetative expansin of the beta-expansin family, greatly inhibited acid-induced extension of native wheat coleoptiles and only one protein band was recognized in Western blot experiments, suggesting that beta-expansins are the main members affecting cell wall extension of wheat coleoptiles. The growth of wheat coleoptiles was closely related to the activity and expression of expansins. In conclusion, our results suggest the presence of expansins in wheat coleoptiles, and it is possible that most of them are members of the beta-expansin family, but are not group 1 grass pollen allergens. The growth of wheat coleoptiles is intimately correlated with expansin expression, in particularly that of beta-expansins. PMID:18726548

Gao, Qiang; Zhao, Meirong; Li, Feng; Guo, Qifang; Xing, Shichao; Wang, Wei

2008-01-01

235

Biomethanation of rice and wheat straw.  

PubMed

When rice or wheat straw was added to cattle dung slurry and digested anaerobically, daily gas production increased from 176 to 331 l/kg total solids with 100% rice straw and to 194 l/kg total solids with 40% wheat straw. Not only was methane production enhanced by adding chopped crop residues but a greater biodegradability of organic matter in the straws was achieved. PMID:24421124

Somayaji, D; Khanna, S

1994-09-01

236

Gluten Protein Composition in Individual Wheat Grains  

Microsoft Academic Search

IT has been well established (by ion-exchange chromatography1,2, moving boundary electrophoresis3 and gel electrophoresis1,4,5) that the protein composition of the acetic acid-soluble material (gluten) is dependent on the variety of wheat from which the protein is extracted. This communication describes the extraction and electrophoretic separation on polyacrylamide of gluten proteins of individual grains from single ears of wheat.

J. W. Lee

1964-01-01

237

Wheat production in controlled environments  

NASA Technical Reports Server (NTRS)

The present optimization study for maximum yield and quality conditions in the lunar or Martian Controlled Environment Life Support System (CELSS)-based growth of wheat has determined that, for 23-57 g/sq m per day of edible biomass, minimum CELSS size must be of the order of 12-30 sq m/person. About 600 W/sq m of electricity would be consumed by the artificial lighting required; temperature, irradiance, photoperiod, CO2 levels, humidity, and wind velocity are all controlled. A rock wool plant support allows direct seeding, and densities of up to 10,000 plants/sq m. Densities of up to 2000 plants/sq m appear to increase seed yields.

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

1987-01-01

238

Effects on performance of ground wheat with or without insoluble fiber or whole wheat in sequential feeding for laying hens.  

PubMed

Sequential feeding (SF) is an innovative system for laying hens consisting of nutrients separating energy, protein, and calcium supplies to fulfill nutrient requirements at the relevant time of day. In previous studies, hens received whole wheat in the morning and a balancer diet (rich in protein and calcium) in the afternoon. To improve SF utilization, the aim was to substitute whole wheat in the morning by an alternative energy supply: ground wheat and ground corn, with or without a proportion of whole wheat and insoluble fiber. The goal was to obtain the advantages observed in previous experiments with whole wheat [bigger gizzard, thinner hens, reduced feed conversion ratio (FCR)]. Four hundred thirty-two ISA Brown hens were housed in collective cages from 20 to 35 wk of age divided into 8 different treatments: a continuous control diet, a sequential diet with whole wheat in the morning, 3 wheat-based diets (ground wheat, ground wheat and 20% whole wheat, and ground wheat with 5% insoluble fiber) and 3 ground corn-based (ground corn, ground corn and 20% whole wheat, and ground corn with 5% insoluble fiber) provided in the morning. All sequential regimens received the same balancer diet rich in protein and calcium in the afternoon. Whole wheat SF gave the best results with an improved FCR compared with continuous control and all other SF diets. Wheat- and corn-based diets showed intermediate results between whole wheat SF and continuous feeding. Gizzard weight was higher and hens were lighter than with conventional continuous feeding, leading to an average FCR improvement of 3.2% compared with a continuous control. Thus, it is possible in SF diets to substitute, at least partially, whole wheat by ground wheat or ground corn with added insoluble fiber or some whole wheat, allowing more flexibility and economic optimization. PMID:23960132

Traineau, M; Bouvarel, I; Mulsant, C; Roffidal, L; Launay, C; Lescoat, P

2013-09-01

239

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

240

Cytokine Induction of Dopamine Neurons from Progenitor Cells.  

National Technical Information Service (NTIS)

Significant progress has been made on all aspects of the originally described work and the project is proceeding as planned and is ahead of schedule. The mesencephalic progenitor cells have been successfully cloned, characterized and shown to share numero...

P. M. Carvey

2000-01-01

241

Stromal-epithelial crosstalk regulates kidney progenitor cell differentiation  

PubMed Central

Current 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/function is regulated by balancing opposing signals from the ureteric bud and stroma to promote renewal and differentiation of the nehron progenitors.

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

2013-01-01

242

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

2013-09-01

243

Double degenerates from the supernova Ia progenitor survey (SPY)  

Microsoft Academic Search

We report on follow-up observations of double degenerate (DD) white dwarfs\\u000afrom the Supernovae Ia Progenitor Survey (SPY). Orbital parameters of four\\u000asystems, including a massive short period system, are presented.

C. Karl; R. Napiwotzki; U. Heber; T. Lisker; G. Nelemans; N. Christlieb; D. Reimers

2002-01-01

244

Suppression of progenitor differentiation requires the long noncoding RNA ANCR  

PubMed Central

Long noncoding RNAs (lncRNAs) regulate diverse processes, yet a potential role for lncRNAs in maintaining the undifferentiated state in somatic tissue progenitor cells remains uncharacterized. We used transcriptome sequencing and tiling arrays to compare lncRNA expression in epidermal progenitor populations versus differentiating cells. We identified ANCR (anti-differentiation ncRNA) as an 855-base-pair lncRNA down-regulated during differentiation. Depleting ANCR in progenitor-containing populations, without any other stimuli, led to rapid differentiation gene induction. In epidermis, ANCR loss abolished the normal exclusion of differentiation from the progenitor-containing compartment. The ANCR lncRNA is thus required to enforce the undifferentiated cell state within epidermis.

Kretz, Markus; Webster, Dan E.; Flockhart, Ross J.; Lee, Carolyn S.; Zehnder, Ashley; Lopez-Pajares, Vanessa; Qu, Kun; Zheng, Grace X.Y.; Chow, Jennifer; Kim, Grace E.; Rinn, John L.; Chang, Howard Y.; Siprashvili, Zurab; Khavari, Paul A.

2012-01-01

245

Quality of shear fractionated wheat gluten – comparison to commercial vital wheat gluten  

Microsoft Academic Search

The functional properties of gluten obtained with a shear-induced separation process, recently proposed by Peighambardoust et al. (2008), are compared with a commercially available vital wheat gluten. Two tests were performed. First, a relatively strong wheat flour, Soissons, was enriched with gluten protein. The resulting dough was then evaluated on its kneading performance. Second, a weak flour, Kolibri, was enriched

Zalm van der E. E. J; Goot van der A. J; R. M. Boom

2011-01-01

246

Quality of shear fractionated wheat gluten – Comparison to commercial vital wheat gluten  

Microsoft Academic Search

The functional properties of gluten obtained with a shear-induced separation process, recently proposed by Peighambardoust et al. (2008), are compared with a commercially available vital wheat gluten. Two tests were performed. First, a relatively strong wheat flour, Soissons, was enriched with gluten protein. The resulting dough was then evaluated on its kneading performance. Second, a weak flour, Kolibri, was enriched to

Elizabeth E. J. van der Zalm; Atze J. van der Goot; Remko M. Boom

2011-01-01

247

Development of hard white winter wheats for a hard red winter wheat region  

Microsoft Academic Search

Hard white winter wheat (HWWW) occupies a very limited area of the USA, but its purported advantages suggest that its production in the major hard red winter wheat (HRWW) region may be feasible. Objectives of our investigations were to develop experimental HWWW lines that combined desirable attributes-grain yield, functional grain quality, and resistance to preharvest sprouting-in single genotypes for comparison

M. P. Upadhyay; G. M. Paulsen; E. G. Heyne; R. G. Sears; R. C. Hoseney

1984-01-01

248

Flavor Characterization of Breads Made from Hard Red Winter Wheat and Hard White Winter Wheat  

Microsoft Academic Search

Cereal Chem. 69(5):556-559 Sensory flavor profiles for white pan bread and whole wheat bread impression than did HRW crust. HRW crumb was sweeter and more made from hard red winter (HRW) or hard white winter (HWW) wheat dairylike than HWW crumb. HWW crumb had a phenoliclike note not were developed by a professionally trained panel. The flavors of crust present

CHUN-YEN CHANG; EDGAR CHAMBERS

249

The production of haploid wheat plants from wheat x maize crosses  

Microsoft Academic Search

Hybrid embryos from hexaploid wheat x maize crosses rapidly lose the maize chromosomes to produce haploid wheat embryos. Such embryos almost always aborted when left to develop on the plant, and only 1 was recovered from 2440 florets (0.17% of the expected number). Embryos had greater viability in spikelet culture, 47 (26.5% of the expected number) being recovered from 706

D. A. Laurie; M. D. Bennett

1988-01-01

250

Population Density and Distribution of Wheat Bugs Infesting Durum Wheat in Sardinia, Italy  

PubMed Central

Wheat is a very important crop in Italy, and is infested by wheat bugs belonging to the genera Eurygaster (Hemiptera: Scutellaridae) and Aelia (Hemiptera: Pentatomidae). Many wheat bug infestations have been reported in the north, south, and center of Italy, both in the past as well as recently. The present study was carried out in Sardinia, Italy, during two years (2007 and 2008). The objective of this study was to determine the species and distribution of wheat bugs in durum wheat fields in Sardinia, and to estimate their population density in order to know the incidence of the pest on the island. Sampling took place twice a year (May and June) in three zones, representative of durum wheat cropping in the island. Four species of wheat bugs were found; the predominant species was Eurygaster austriaca (Schrank), followed by Aelia germari (Kuster), Eurygaster maura L., and Aelia acuminata L. The average density of wheat bugs was low (1.1 individuals/m2), but in certain areas it was above the damage threshold (4 individuals/m2). For this reason, the conclusion of the study is that this pest should be monitored in order to control outbreaks and prevent their further spread.

Salis, Luigi; Goula, Marta; Izquierdo, Jordi; Gordun, Elena

2013-01-01

251

Feeding value of wet tomato pomace ensiled with wheat straw and wheat grain for Awassi sheep  

Microsoft Academic Search

In this study, two experiments were conducted to preserve tomato pomace (TP) by ensiling it with different levels of wheat straw (WS) and wheat grain (WG) to improve feeding value, digestibility, and acceptability of this source. Experiment I was arranged in a 3×4 factorial in which WS level (10, 15, and 20%) and WG (ground) level (0, 2, 4, and

N. Denek; A. Can

2006-01-01

252

Comprehensive methylome map of lineage commitment from haematopoietic progenitors  

Microsoft Academic Search

Epigenetic modifications must underlie lineage-specific differentiation as terminally differentiated cells express tissue-specific genes, but their DNA sequence is unchanged. Haematopoiesis provides a well-defined model to study epigenetic modifications during cell-fate decisions, as multipotent progenitors (MPPs) differentiate into progressively restricted myeloid or lymphoid progenitors. Although DNA methylation is critical for myeloid versus lymphoid differentiation, as demonstrated by the myeloerythroid bias in

Hong Ji; Lauren I. R. Ehrlich; Jun Seita; Peter Murakami; Akiko Doi; Paul Lindau; Hwajin Lee; Martin J. Aryee; Rafael A. Irizarry; Kitai Kim; Derrick J. Rossi; Matthew A. Inlay; Thomas Serwold; Holger Karsunky; Lena Ho; George Q. Daley; Irving L. Weissman; Andrew P. Feinberg

2010-01-01

253

Hyperpolarization Induces Differentiation in Human Cardiomyocyte Progenitor Cells  

Microsoft Academic Search

In the past years, cardiovascular progenitor cells have been isolated from the human heart and characterized. These cells\\u000a can differentiate into cardiomyocytes, smooth muscle cells and endothelial cells and are therefore of great value for investigation\\u000a of the mechanisms that drive progenitor cell function and plasticity, drug testing and, potentially, therapeutical purposes.\\u000a In this respect, most studies have focused on

Patrick van Vliet; Teun P. de Boer; Mazen K. El Tamer; Joost P. G. Sluijter; Pieter A. Doevendans; Marie-José Goumans

2010-01-01

254

Hepatic progenitor cells express SerpinB3  

PubMed Central

Background In the setting of liver injury hepatic progenitor cells are activated, counterbalancing the inhibited regenerative capacity of mature hepatocytes. Chronic activation of this compartment may give rise to a subset of liver tumours with poor prognosis. SerpinB3, a serpin over-expressed in injured liver and in primary liver cancer, has been shown to induce apoptosis resistance, epithelial to mesenchymal transition and to increase TGF-beta and Myc expression. Aim of the present study was to explore the presence of SerpinB3 in hepatic progenitor cells in human livers and in a mouse model of liver stem/progenitor cell activation. Hepatic progenitor cells were analysed in foetal and adult livers at protein and transcriptional levels. To induce experimental activation of the liver stem/progenitor compartment, C57BL/6J mice were injected with lipopolysaccharide plus D-galactosamine and were sacrificed at different time points. Liver cDNA was amplified using specific primers for mouse-homologous SerpinB3 isoforms and automatically sequenced. Results The presence of SerpinB3 in the progenitor cell compartment was detected in sorted human foetal and adult epithelial cell adhesion molecule (EpCAM) positive liver cells. By immunohistochemistry SerpinB3 was found in human cirrhotic livers in portal areas with progenitor cell activation showing ductular proliferation. CK-7, CK-19, EpCAM and CD-90 positive cell were also positive for SerpinB3. In the animal model, time course analysis in liver specimens revealed a progressive increase of SerpinB3 and a parallel decrease of activated caspase 3, which was barely detectable at 20 hours. Transcription analysis confirmed the presence of SerpinB3-homologous only in the liver of injured mice and sequence analysis proved its belonging to mouse Serpinb3b. Conclusion SerpinB3 is highly expressed in hepatic stem/progenitor cell compartment of both foetal and adult livers.

2014-01-01

255

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

256

Cyclin D2 controls B cell progenitor numbers  

Microsoft Academic Search

Cyclin D2 affects B cell proliferation and differentiation in vivo. It is rate-limiting for B cell receptor (BCR)-dependent proliferation of B cells, and cyclin D2\\/ mice lack CD5(B1) B lymphocytes. We show here that the bone marrow (BM) of cyclin D2\\/ mice contains half the num- bers of Sca1B220 B cell progenitors but nor- mal levels of Sca1 progenitor cells

Azim Mohamedali; Ines Soeiro; Nicholas C. Lea; Janet Glassford; Lolita Banerji; Ghulam J. Mufti; Eric W.-F. Lam; N. Shaun; B. Thomas

2003-01-01

257

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

258

Vascular calcifying progenitor cells possess bidirectional differentiation potentials.  

PubMed

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. PMID:23585735

Cho, Hyun-Ju; Cho, Hyun-Jai; 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

259

Testing and validating the CERES-wheat (Crop Estimation through Resource and Environment Synthesis-wheat) model in diverse environments  

NASA Technical Reports Server (NTRS)

CERES-Wheat is a computer simulation model of the growth, development, and yield of spring and winter wheat. It was designed to be used in any location throughout the world where wheat can be grown. The model is written in Fortran 77, operates on a daily time stop, and runs on a range of computer systems from microcomputers to mainframes. Two versions of the model were developed: one, CERES-Wheat, assumes nitrogen to be nonlimiting; in the other, CERES-Wheat-N, the effects of nitrogen deficiency are simulated. The report provides the comparisons of simulations and measurements of about 350 wheat data sets collected from throughout the world.

Otter-Nacke, S.; Godwin, D. C.; Ritchie, J. T.

1986-01-01

260

Alkylresorcinols in wheat varieties in the HEALTHGRAIN Diversity Screen.  

PubMed

The contents of alkylresorcinols (AR) were analyzed in 131 winter wheats, 20 spring wheats, 10 durum wheats, 5 spelt wheats, and 10 early cultivated forms of wheat (5 diploid einkorn and 5 tetraploid emmer), which are part of the HEALTHGRAIN diversity screen. AR were analyzed by gas chromatography (GC), which provides both total contents and relative homologue compositions, as well as with a Fast Blue colorimetric method that provides only total contents but which is fast and easily screens a large number of samples. There was considerable variation in the total AR content analyzed with GC: winter wheat (220-652 microg/g of dm), spring wheat (254-537 microg/g of dm), durum wheat (194-531 microg/g of dm), spelt (490-741 microg/g of dm), einkorn (545-654 microg/g of dm), and emmer wheat (531-714 microg/g of dm). The relative AR homologue composition was different for different types of wheat, with a C17:0 to C21:0 ratio of 0.1 for winter, spring, and spelt wheats, 0.04 for einkorn and emmer wheat, and 0.01 for durum wheat. The total AR content analyzed with the Fast Blue method was lower than that analyzed with GC but there was a good correlation between the two methods (R(2) = 0.76). PMID:18921971

Andersson, Annica A M; Kamal-Eldin, Afaf; Fra?, Anna; Boros, Danuta; Aman, Per

2008-11-12

261

Constraining fast radio burst progenitors with gravitational lensing  

NASA Astrophysics Data System (ADS)

Fast Radio Bursts (FRBs) are new transient radio sources discovered recently. Because of the angular resolution restriction in radio surveys, no optical counter part has been identified yet so it is hard to determine the progenitor of FRBs. In this paper we propose to use radio lensing survey to constrain FRB progenitors. We show that, different types of progenitors lead to different probabilities for a FRB to be gravitationally lensed by dark matter halos in foreground galaxies, since different type progenitors result in different redshift distributions of FRBs. For example, the redshift distribution of FRBs arising from double stars shifts toward lower redshift than of the FRBs arising from single stars, because double stars and single stars have different evolution timescales. With detailed calculations, we predict that the FRB sample size for producing one lensing event varies significantly for different FRB progenitor models. We argue that this fact can be used to distinguish different FRB models and also discuss the practical possibility of using lensing observation in radio surveys to constrain FRB progenitors.

Li, ChunYu; Li, LiXin

2014-07-01

262

Constraining fast radio burst progenitors with gravitational lensing  

NASA Astrophysics Data System (ADS)

Fast Radio Bursts (FRBs) are new transient radio sources discovered recently. Because of the angular resolution restriction in radio surveys, no optical counter part has been identified yet so it is hard to determine the progenitor of FRBs. In this paper we propose to use radio lensing survey to constrain FRB progenitors. We show that, different types of progenitors lead to different probabilities for a FRB to be gravitationally lensed by dark matter halos in foreground galaxies, since different type progenitors result in different redshift distributions of FRBs. For example, the redshift distribution of FRBs arising from double stars shifts toward lower redshift than of the FRBs arising from single stars, because double stars and single stars have different evolution timescales. With detailed calculations, we predict that the FRB sample size for producing one lensing event varies significantly for different FRB progenitor models. We argue that this fact can be used to distinguish different FRB models and also discuss the practical possibility of using lensing observation in radio surveys to constrain FRB progenitors.

Li, ChunYu; Li, LiXin

2014-05-01

263

Viral disruption of olfactory progenitors is exacerbated in allergic mice.  

PubMed

Upper airway viral infection in patients with airway allergy often exacerbates olfactory dysfunction, but the mechanism for this exacerbation remains unclear. Here, we examined the effects of respiratory syncytial virus (RSV) infection, in the presence or absence of airway allergy, on olfactory receptor neurons (ORNs) and their progenitors in mice. Immunohistological analyses revealed that cockroach allergen (CRA)-induced airway allergy alone did not affect the number of OMP(+) mature ORNs and SOX2(+) ORN progenitors. Intranasal RSV line 19 infection in allergy-free mice resulted in a transient decrease in SOX2(+) ORN progenitors without affecting OMP(+) ORNs. In contrast, the RSV-induced decrease in SOX2(+) ORN progenitors was exacerbated and prolonged in allergic mice, which resulted in eventual loss of OMP(+) ORNs. In the allergic mice, reduction of RSV in the olfactory epithelium was delayed as compared with allergy-free mice. These results suggest that ORN progenitors were impaired by RSV infection and that airway allergy exacerbated damage to ORN progenitors by reducing viral clearance. PMID:24998164

Ueha, R; Mukherjee, S; Ueha, S; de Almeida Nagata, D E; Sakamoto, T; Kondo, K; Yamasoba, T; Lukacs, N W; Kunkel, S L

2014-09-01

264

Isolation of an adult mouse lung mesenchymal progenitor cell population.  

PubMed

Contained within the adult lung are differentiated mesenchymal cell types (cartilage, smooth muscle, and myofibrobasts) that provide structural support for airways and vessels. Alterations in the number and phenotype of these cells figure prominently in the pathogenesis of a variety of lung diseases. While these cells are thought to arise locally, progenitors have yet to be purified. In previous work, we developed a method for isolating progenitors from lung tissue: this technique takes advantage of the unique ability of cell populations enriched for somatic stem and progenitor activity to efflux the vital dye Hoechst 33342, a feature that permits isolation by flow cytometry-based procedures. Using this method, we determined that a rare population of mesenchymal progenitors resides within the CD45- CD31- Hoechst low fraction of the adult murine lung. Similar to other mesenchymal progenitors, these cells express Sca-1, CD106, and CD44; can be serially passaged; and can differentiate to smooth muscle, cartilage, bone, and fat. Overall, these findings demonstrate that a phenotypically distinct mesenchymal progenitor resides within the adult murine lung, and provide a scheme for their isolation and study. PMID:17395889

Summer, Ross; Fitzsimmons, Kathleen; Dwyer, Daniel; Murphy, Jaime; Fine, Alan

2007-08-01

265

MiR-223 deficiency increases eosinophil progenitor proliferation  

PubMed Central

Recently, microRNAs (miRNAs) have been shown to be involved in hematopoietic cell development but their role in eosinophilopoeisis has not yet been described. Here we show that miR-223 is up-regulated 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 up-regulation of a miR-223 target gene – IGF1R in the eosinophil progenitor cultures derived from miR-223-/- mice compared to miR-223+/+ littermate controls. The increased proliferation of miR-223-/- eosinophil progenitors was reversed by treatment with the 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 miRNAs regulate the development of eosinophils by influencing eosinophil progenitor growth and differentiation and identify a contributory role for miR-223 in this process.

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

2012-01-01

266

How Low Can They Go? Detecting low luminosity supernova progenitors  

NASA Astrophysics Data System (ADS)

While we now discover thousands of supernovae {SNe} per year, in the history of astronomy a little more than a dozen SN progenitors have been identified, and all of these have been from Type II SNe. This dearth is largely due to the fact that the progenitors are destroyed in the SN, and so to study them one must have fortuitously taken data on them prior to their explosion. However, the fault may also partially lie with the methods employed to search for progenitors.In the past, searches have generally relied on looking at the location of a SNe in an archival image to see if a noticeable point source is at the right location. This method requires that the background field of the galaxy be relatively uniform, and if one wants an accurate estimate of the progenitor mangitude, that the star was not in an association or binary. Here we propose to take WFC3 images several years post explosion so that we can subtract them from archival WFPC2 images. We show that we can do this with extraordinary fidelity. We will apply this method to a well-chosen sample of three Type II SNe and two Type Ibc SNe, which lie on messy galaxy fields that may have camouflaged the presence of a progenitor. This method has the potential to detect or substantially deepen the limits on the progenitors of these objects, which already appear too faint for theoretical models.;

Fruchter, Andrew

2012-07-01

267

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

2013-02-15

268

Human adult white matter progenitor cells are multipotent neuroprogenitors similar to adult hippocampal progenitors.  

PubMed

Adult neural progenitor cells (aNPC) are a potential autologous cell source for cell replacement in neurologic diseases or for cell-based gene therapy of neurometabolic diseases. Easy accessibility, long-term expandability, and detailed characterization of neural progenitor cell (NPC) properties are important requisites for their future translational/clinical applications. aNPC can be isolated from different regions of the adult human brain, including the accessible subcortical white matter (aNPCWM), but systematic studies comparing long-term expanded aNPCWM with aNPC from neurogenic brain regions are not available. Freshly isolated cells from subcortical white matter and hippocampus expressed oligodendrocyte progenitor cell markers such as A2B5, neuron-glial antigen 2 (NG2), and oligodendrocyte transcription factor 2 (OLIG2) in ?20% of cells but no neural stem cell (NSC) markers such as CD133 (Prominin1), Nestin, SOX2, or PAX6. The epidermal growth factor receptor protein was expressed in 18% of aNPCWM and 7% of hippocampal aNPC (aNPCHIP), but only a small fraction of cells, 1 of 694 cells from white matter and 1 of 1,331 hippocampal cells, was able to generate neurospheres. Studies comparing subcortical aNPCWM with their hippocampal counterparts showed that both NPC types expressed mainly markers of glial origin such as NG2, A2B5, and OLIG2, and the NSC/NPC marker Nestin, but no pericyte markers. Both NPC types were able to produce neurons, astrocytes, and oligodendrocytes in amounts comparable to fetal NSC. Whole transcriptome analyses confirmed the strong similarity of aNPCWM to aNPCHIP. Our data show that aNPCWM are multipotent NPC with long-term expandability similar to NPC from hippocampus, making them a more easily accessible source for possible autologous NPC-based treatment strategies. PMID:24558163

Lojewski, Xenia; Hermann, Andreas; Wegner, Florian; Araúzo-Bravo, Marcos J; Hallmeyer-Elgner, Susanne; Kirsch, Matthias; Schwarz, Johannes; Schöler, Hans R; Storch, Alexander

2014-04-01

269

Relationship between lutein and mycotoxin content in durum wheat.  

PubMed

Levels of lutein and a number of mycotoxins were determined in seven varieties of durum wheat (Triticum durum) and two varieties of common wheat (Triticum aestivum) in order to explore possible relationships amongst these components. Durum wheat cultivars always showed both higher lutein and mycotoxin contents than common wheat cultivars. The mycotoxins detected in both common and durum wheat cultivars were produced by the genera Fusarium, Claviceps, Alternaria and Aspergillus. Fusarium was the major producer of mycotoxins (26 mycotoxins) followed by Claviceps (14 mycotoxins), which was present only in some cultivars such as Chevalier (common wheat), Lupidur and Selyemdur (both durum wheat), Alternaria (six mycotoxins) and Aspergillus (three mycotoxins). Positive correlations between the levels of lutein and mycotoxins in durum wheat cultivars were found for the following mycotoxins: deoxynivalenol (DON), its derivative DON-3-glucoside, moniliformin, culmorin and its derivatives (5-hydroxyculmorin and 15-hydroxyculmorin). PMID:24844356

Delgado, Rosa M; Sulyok, Michael; Jirsa, Ond?ej; Spitzer, Tomáš; Krska, Rudolf; Polišenská, Ivana

2014-07-01

270

Morphological features and physicochemical properties of waxy wheat starch.  

PubMed

Morphological features, granule composition, and physicochemical properties of waxy wheat starch were compared with those of normal wheat starch. The morphologies and granule populations were found to be similar for the two starches. However, waxy wheat starch contained a smaller proportion of B-type granules, had a larger average granule diameter, and a higher degree of crystallinity than normal wheat starch, as measured by particle size analysis and differential scanning calorimetry. These differences resulted in a higher gelatinization temperature, transition enthalpy, peak viscosity, breakdown, swelling power, lower peak viscosity temperature and final viscosity in waxy wheat starch. These points suggest that waxy wheat starch should have greater resistance to retrogradation during cooling and higher water-holding capacity under dry conditions. Highlighting the differences in physicochemical properties of waxy and normal wheat starches should help point toward effective applications of waxy wheat starch in the food industry. PMID:24076202

Zhang, Huanxin; Zhang, Wei; Xu, Chunzhong; Zhou, Xing

2013-11-01

271

19 CFR 19.32 - Wheat manipulation; reconditioning.  

Code of Federal Regulations, 2013 CFR

...PROTECTION, DEPARTMENT OF HOMELAND SECURITY; DEPARTMENT OF THE TREASURY CUSTOMS WAREHOUSES, CONTAINER STATIONS AND CONTROL OF MERCHANDISE THEREIN Space Bonded for the Storage of Wheat § 19.32 Wheat manipulation; reconditioning....

2013-04-01

272

Comprehensive study of valuable lipophilic phytochemicals in wheat bran.  

PubMed

Wheat bran, the major side-stream generated in the milling of wheat grains in the production of white flour, contains significant quantities of carbohydrate and proteins. While not interfering with flour utilization, the bran could be considered as an important feedstock within a biorefinery concept. Wheat bran also contains some amounts of lipids that can be used as a source of valuable phytochemicals. Gas chromatography and mass spectrometry analysis of the lipid composition of destarched wheat bran demonstrated that the predominant lipids found in wheat bran were free fatty acids (ca. 40% of total lipids), followed by acylglycerols (40%). Additionally, important amounts of alkylresorcinols (13% of total lipids) and steroid compounds (hydrocarbons, ketones, free sterols, sterol glycosides, sterol esters, and sterol ferulates) (7% of total lipids) were also present among the lipids of wheat bran. The use of wheat bran as a valuable source of phytochemicals of interest in the context of a wheat bran biorefinery is discussed. PMID:24450837

Prinsen, Pepijn; Gutiérrez, Ana; Faulds, Craig B; del Río, José C

2014-02-19

273

Gluten and wheat intolerance today: are modern wheat strains involved?  

PubMed

Abstract Celiac disease is a food-induced enteropathy resulting from exposure to gluten in genetically predisposed individuals. The non-celiac gluten sensitivity (NCGS) is a less known syndrome whose prevalence is under-estimated. The last decades have seen changes in the clinical presentation of both diseases. One possible explanation is that changes in the gluten-rich cereals themselves were the principal causes. Celiac-triggering gluten proteins are indeed expressed to higher levels in modern cereals while non-triggering proteins are expressed less. Sophisticated hybridization techniques have been used to produce new strains of modern wheat, the most high-yielding of which have since made their way into human foods in the absence of animal or human safety testing. The dramatic changes in the clinical presentation of celiac disease and NCGS have taken place when new cereal hybrids were introduced into human foods. This is a critical medical and environmental issue which needs to be investigated by appropriate studies. PMID:24524657

de Lorgeril, Michel; Salen, Patricia

2014-08-01

274

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

275

Cardiogenic Differentiation and Transdifferentiation of Progenitor Cells  

PubMed Central

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 one billion cardiomyocytes, and so 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 current state of the evidence for the cardiogenic and regenerative potential of the major candidate stem cell types.

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

2009-01-01

276

Stem/Progenitor cells in vascular regeneration.  

PubMed

A series of studies has been presented in the search for proof of circulating and resident vascular progenitor cells, which can differentiate into endothelial and smooth muscle cells and pericytes in animal and human studies. In terms of pluripotent stem cells, including embryonic stem cells, iPS, and partial-iPS cells, they display a great potential for vascular lineage differentiation. Development of stem cell therapy for treatment of vascular and ischemic diseases remains a major challenging research field. At the present, there is a clear expansion of research into mechanisms of stem cell differentiation into vascular lineages that are tested in animal models. Although there are several clinical trials ongoing that primarily focus on determining the benefits of stem cell transplantation in ischemic heart or peripheral ischemic tissues, intensive investigation for translational aspects of stem cell therapy would be needed. It is a hope that stem cell therapy for vascular diseases could be developed for clinic application in the future. PMID:24828515

Zhang, Li; Xu, Qingbo

2014-06-01

277

Progenitors of electron-capture supernovae  

NASA Astrophysics Data System (ADS)

We investigate the lowest mass stars that produce Type-II supernovae, motivated by recent results showing that a large fraction of type-II supernova progenitors for which there are direct detections display unexpectedly low luminosity (for a review see e.g. Smartt 2009). There are three potential evolutionary channels leading to this fate. Alongside the standard `massive star' Fe-core collapse scenario we investigate the likelihood of electron capture supernovae (EC-SNe) from super-AGB (S-AGB) stars in their thermal pulse phase, from failed massive stars for which neon burning and other advanced burning stages fail to prevent the star from contracting to the critical densities required to initiate rapid electron-capture reactions and thus the star's collapse. We find it indeed possible that both of these relatively exotic evolutionary channels may be realised but it is currently unclear for what proportion of stars. Ultimately, the supernova light curves, explosion energies, remnant properties (see e.g. Knigge et al. 2011) and ejecta composition are the quantities desired to establish the role that these stars at the lower edge of the massive star mass range play.

Jones, Samuel; Hirschi, Raphael; Herwig, Falk; Paxton, Bill; Timmes, Francis X.; Nomoto, Ken'ichi

2012-09-01

278

Human retinal progenitor cell transplantation preserves vision.  

PubMed

Cell transplantation is a potential therapeutic strategy for retinal degenerative diseases involving the loss of photoreceptors. However, it faces challenges to clinical translation due to safety concerns and a limited supply of cells. Human retinal progenitor cells (hRPCs) from fetal neural retina are expandable in vitro and maintain an undifferentiated state. This study aimed to investigate the therapeutic potential of hRPCs transplanted into a Royal College of Surgeons (RCS) rat model of retinal degeneration. At 12 weeks, optokinetic response showed that hRPC-grafted eyes had significantly superior visual acuity compared with vehicle-treated eyes. Histological evaluation of outer nuclear layer (ONL) characteristics such as ONL thickness, spread distance, and cell count demonstrated a significantly greater preservation of the ONL in hRPC-treated eyes compared with both vehicle-treated and control eyes. The transplanted hRPCs arrested visual decline over time in the RCS rat and rescued retinal morphology, demonstrating their potential as a therapy for retinal diseases. We suggest that the preservation of visual acuity was likely achieved through host photoreceptor rescue. We found that hRPC transplantation into the subretinal space of RCS rats was well tolerated, with no adverse effects such as tumor formation noted at 12 weeks after treatment. PMID:24407289

Luo, Jing; Baranov, Petr; Patel, Sherrina; Ouyang, Hong; Quach, John; Wu, Frances; Qiu, Austin; Luo, Hongrong; Hicks, Caroline; Zeng, Jing; Zhu, Jing; Lu, Jessica; Sfeir, Nicole; Wen, Cindy; Zhang, Meixia; Reade, Victoria; Patel, Sara; Sinden, John; Sun, Xiaodong; Shaw, Peter; Young, Michael; Zhang, Kang

2014-03-01

279

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

280

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

281

Wheat x pearl millet hybridization: consequence and potential  

Microsoft Academic Search

Eight grain pearl millet (2n=14) accessions were crossed as male to hexaploid spring wheat cv. ‘Fukuho’ (2n=6x=42). An average of 80% wheat pistils showed pearl millet pollen tube entry in the ovules, compared to 56% in wheat x maize cv. ‘Seneca 60’ cross. Of the 15 embryos, obtained through in vitro immature seed culture from wheat x pearl millet crosses,

F. Ahmadl; A. Comeau

1990-01-01

282

COLOUR ASSESSMENT ON BREAD WHEAT AND TRITICALE FRESH PASTA  

Microsoft Academic Search

Although durum wheat is the cereal of choice for pasta production, in many areas of Argentina pasta is made from bread wheat, since durum wheat is cultivated only in a small region of the country. The purpose of this work was determining the influence of different bread flours on the colour of laminated fresh pasta. Triticale flour was also studied.

C. S. Martinez; P. D. Ribotta; A. E. Leon; M. C. Añon

2011-01-01

283

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

284

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

285

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

286

Recognition of wheat preharvest sprouting based on hyperspectral imaging  

NASA Astrophysics Data System (ADS)

An imaging spectrometer was used to acquire hyperspectral images of 120 strains of wheat ears and seeds under four different watering treatments. Whether wheat preharvest sprouting occurred could be reflected by spectral characteristics. Therefore, it was possible to judge whether wheat ears sprouted according to changes of spectral curve at 675 nm. According to principal component analysis of mean spectral reflectivity values of wheat seeds, it was found that wheat seeds watered three times every day and wheat seeds watered once every day were significantly different from nonsprouting wheat seeds soaked all day and original dry seeds due to significant sprouting situations, suggesting that imaging spectra can differentiate different extent of wheat preharvest sprouting. Glume had an influence on the hyperspectral images of wheat ears, therefore the hyperspectral images of wheat ears could be used to measure sprouting only when serious sprouting occurred. At an early stage of sprouting, only the hyperspectral images of wheat seeds could be used to analyze the sprouting of wheat.

Wu, Qiong; Zhu, Dazhou; Wang, Cheng; Ma, Zhihong; Wang, Jihua

2012-11-01

287

Pharmacological Studies of the Effect of Wheat Grain Extract  

Microsoft Academic Search

Background: Agricultural farm workers exposed to wheat grain dust are at risk of developing respiratory abnormalities. The pathogenesis of this injury is only partially understood. Objectives: To determine the effect of wheat grainextract on isolated guinea pig tracheal smooth muscle. Methods: In the current study, pharmacologic properties of wheat grain extract (WGE) were tested using guinea pig tracheas studied in

E. Neil Schachter; Eugenija Zuskin; Nicholas Rienzi; Satindra Goswami; Vincent Castranova; Paul Siegel; Michael Whitmer; Eric Chung

2004-01-01

288

Rheological Behavior of Undeveloped and Developed Wheat Dough  

Microsoft Academic Search

Cereal Chem. 74(4):489-494 Undeveloped wheat dough is essentially wheat flour that has become fully hydrated without being deformed. The rheological properties of this material were compared to dough (developed dough) made using the standard method involving a farinograph. Flow behavior of undeveloped and developed dough samples made from hard and soft wheat flours were tested using creep tests, frequency sweep

Danilo T. Campos; James F. Steffe; Perry K. W. Ng

1997-01-01

289

Fusarium head blight and mycotoxin contamination of wheat, a review  

Microsoft Academic Search

Summary An infection of bread wheat by fusarium head blight contaminates the crop with mycotoxins, particularly deoxynivalenol (DON) and nivalenol (NIV). The toxicity and natural occurrence of these mycotoxins in wheat are reviewed. Based on 8 years data of fusarium head blight epidemics of wheat in the Netherlands, DON contamination of the grain was estimated. Fusarium head blight ratings averaged

C. H. A. Snijders

1990-01-01

290

Flow behaviour parameters of wheat flours using triaxial cell  

Microsoft Academic Search

Whole wheat and enriched wheat flours were tested using a triaxial testing apparatus to examine their flow behavior. Confining pressures of 100, 200 and 300 kPa were applied. Based on the experimental data, the yield loci of mohr circles, which represent the flow behavior, were studied. Whole wheat flour has cohesion of 53 kPa and angle of internal friction of

G. S. Mittal; Jixian Zhang

2000-01-01

291

Colour Assessment on Bread Wheat and Triticale Fresh Pasta  

Microsoft Academic Search

Although durum wheat is the cereal of choice for pasta production, in many areas of Argentina pasta is made from bread wheat, since durum wheat is cultivated only in a small region of the country. The purpose of this work was to determine the influence of different bread flours on the colour of laminated fresh pasta. Triticale flour was also

C. S. Martinez; P. D. Ribotta; A. E. Leon; M. C. Añon

2012-01-01

292

The Effect of Friabilin on Wheat Grain Hardness  

Microsoft Academic Search

A wheat marketing system established the primary classification of hexaploid wheat based on the endosperm texture, i.e. hardness or softness of the grain. Hardness affects a range of characters including the milling (tempering, milling yield, flour particle size, shape and density of flour particles), baking and end-use properties. Wheat grain hardness is largely controlled by genetic factors but it can

Daniela MIKULÍKOVÁ

2007-01-01

293

Genome Evolution Due to Allopolyploidization in Wheat  

PubMed Central

The wheat group has evolved through allopolyploidization, namely, through hybridization among species from the plant genera Aegilops and Triticum followed by genome doubling. This speciation process has been associated with ecogeographical expansion and with domestication. In the past few decades, we have searched for explanations for this impressive success. Our studies attempted to probe the bases for the wide genetic variation characterizing these species, which accounts for their great adaptability and colonizing ability. Central to our work was the investigation of how allopolyploidization alters genome structure and expression. We found in wheat that allopolyploidy accelerated genome evolution in two ways: (1) it triggered rapid genome alterations through the instantaneous generation of a variety of cardinal genetic and epigenetic changes (which we termed “revolutionary” changes), and (2) it facilitated sporadic genomic changes throughout the species’ evolution (i.e., evolutionary changes), which are not attainable at the diploid level. Our major findings in natural and synthetic allopolyploid wheat indicate that these alterations have led to the cytological and genetic diploidization of the allopolyploids. These genetic and epigenetic changes reflect the dynamic structural and functional plasticity of the allopolyploid wheat genome. The significance of this plasticity for the successful establishment of wheat allopolyploids, in nature and under domestication, is discussed.

Feldman, Moshe; Levy, Avraham A.

2012-01-01

294

Adapting wheat in Europe for climate change  

PubMed Central

Increasing cereal yield is needed to meet the projected increased demand for world food supply of about 70% by 2050. Sirius, a process-based model for wheat, was used to estimate yield potential for wheat ideotypes optimized for future climatic projections for ten wheat growing areas of Europe. It was predicted that the detrimental effect of drought stress on yield would be decreased due to enhanced tailoring of phenology to future weather patterns, and due to genetic improvements in the response of photosynthesis and green leaf duration to water shortage. Yield advances could be made through extending maturation and thereby improve resource capture and partitioning. However the model predicted an increase in frequency of heat stress at meiosis and anthesis. Controlled environment experiments quantify the effects of heat and drought at booting and flowering on grain numbers and potential grain size. A current adaptation of wheat to areas of Europe with hotter and drier summers is a quicker maturation which helps to escape from excessive stress, but results in lower yields. To increase yield potential and to respond to climate change, increased tolerance to heat and drought stress should remain priorities for the genetic improvement of wheat.

Semenov, M.A.; Stratonovitch, P.; Alghabari, F.; Gooding, M.J.

2014-01-01

295

Mouse ES cell-derived hematopoietic progenitor cells.  

PubMed

Future stem cell-based therapies will benefit from the new discoveries being made on pluripotent stem cells such as embryonic stem (ES) cells and induced pluripotent stem (IPS) cells. Understanding the genes regulating pluripotency has opened new opportunities to generate patient-tailored therapies. However, protocols for deriving progenitor cells of therapeutic grade from these pluripotent stem cells are not yet worked out. In particular the potential of these cells in treating diseases when compared to their adult progenitor counterparts is unknown. This is crucial work that needs to be studied in detail because we will need to determine engraftment potential of these cells and their ability for multi-lineage engraftment in the in vivo setting before any clinical applications. The ability of these cells to engraft is dependent on their expression of cell surface markers which guide their homing patterns. In this review, I discuss murine hematopoietic progenitor cells derived from mouse ES cells. Stem cells in the bone marrow are found in the bone marrow niches. Our knowledge of the bone marrow niches is growing and will ultimately lead to improved clinical transplantation of bone marrow cells. We are, however, a long way in appreciating how hematopoietic progenitor cells migrate and populate lymphoid tissues. One of the variables in generating hematopoietic progenitor cells is that different labs use different approaches in generating progenitor cells. In some cases, the ES cell lines used show some variability as well. The cell culture media used by the different investigators highly influence the maturation level of the cells and their homing patterns. Here, mouse ES cell-derived progenitor cells are discussed. PMID:23756945

Kim, Eun-Mi; Manzar, Gohar; Zavazava, Nicholas

2013-01-01

296

Circulating Hematopoietic Progenitor Cells are Decreased in COPD.  

PubMed

Abstract Rationale: Bone marrow derived progenitor cells participate in the repair of injured vessels. The lungs of individuals with emphysema have reduced alveolar capillary density and increased endothelial apoptosis. We hypothesized that circulating levels of endothelial and hematopoietic progenitor cells would be reduced in this group of patients. Objectives: The goal of this study was to measure circulating levels of endothelial progenitor cells (EPCs) and hematopoietic progenitor cells (HPCs) in subjects with COPD and to determine if progenitor levels correlated with disease severity and the presence of emphysema. Methods: Peripheral blood mononuclear cells were isolated from 61 patients with COPD and 32 control subjects. Levels of EPCs (CD45(dim) CD34+) and HPCs (CD45(+) CD34(+) VEGF-R2(+)) were quantified using multi-parameter flow cytometry. Progenitor cell function was assessed using cell culture assays. All subjects were evaluated with spirometry and CT scanning. Measurements and Main Results: HPC levels were reduced in subjects with COPD compared to controls, whereas circulating EPC levels were similar between the two groups. HPC levels correlated with severity of obstruction and were lowest in subjects with severe emphysema. These associations remained after correction for factors known to affect progenitor cell levels including age, smoking status, the use of statin medications and the presence of coronary artery disease. The ability of mononuclear cells to form endothelial cell colony forming units (EC-CFU) was also reduced in subjects with COPD. Conclusions: HPC levels are reduced in subjects with COPD and correlate with emphysema phenotype and severity of obstruction. Reduction of HPCs may disrupt maintenance of the capillary endothelium, thereby contributing to the pathogenesis of COPD. PMID:24182349

Janssen, William J; Yunt, Zulma X; Muldrow, Alaina; Kearns, Mark T; Kloepfer, Angela; Barthel, Lea; Bratton, Donna L; Bowler, Russell P; Henson, Peter M

2014-06-01

297

Circulating Hematopoietic Progenitor Cells are Decreased in COPD  

PubMed Central

Rationale Bone marrow derived progenitor cells participate in the repair of injured vessels. The lungs of individuals with emphysema have reduced alveolar capillary density and increased endothelial apoptosis. We hypothesized that circulating levels of endothelial and hematopoietic progenitor cells would be reduced in this group of patients. Objectives The goal of this study was to measure circulating levels of endothelial progenitor cells (EPCs) and hematopoietic progenitor cells (HPCs) in subjects with COPD and to determine if progenitor levels correlated with disease severity and the presence of emphysema. Methods Peripheral blood mononuclear cells were isolated from 61 patients with COPD and 32 control subjects. Levels of EPCs (CD45dim CD34+ ) and HPCs (CD45+ CD34+ VEGF-R2+) were quantified using multi-parameter flow cytometry. Progenitor cell function was assessed using cell culture assays. All subjects were evaluated with spirometry and CT scanning. Measurements and Main Results HPC levels were reduced in subjects with COPD compared to controls, whereas circulating EPC levels were similar between the two groups. HPC levels correlated with severity of obstruction and were lowest in subjects with severe emphysema. These associations remained after correction for factors known to affect progenitor cell levels including age, smoking status, the use of statin medications and the presence of coronary artery disease. The ability of mononuclear cells to form endothelial cell colony forming units (EC-CFU) was also reduced in subjects with COPD. Conclusions HPC levels are reduced in subjects with COPD and correlate with emphysema phenotype and severity of obstruction. Reduction of HPCs may disrupt maintenance of the capillary endothelium, thereby contributing to the pathogenesis of COPD.

Janssen, William J.; Yunt, Zulma X.; Muldrow, Alaina; Kearns, Mark T.; Kloepfer, Angela; Barthel, Lea; Bratton, Donna L.; Bowler, Russell P.; Henson, Peter M.

2014-01-01

298

Molecular characterization of Haynaldia villosa chromatin in wheat lines carrying resistance to wheat curl mite colonization.  

PubMed

Wheat-Haynaldia villosa (L.) Schur, hybrid lines were tested as potential sources of resistance to colonization by the wheat curl mite, the vector of wheat streak mosaic virus. Two lines, Add 6V-1 and Sub 6V-1, were found to be mite-resistant. Fluorescence in situ hybridization using total genomic DNA, from H. villosa in the presence of unlabelled wheat DNA, confirmed that Add 6V-1 is a disomic wheat-H. villosa chromosome addition line. Sub 6V-1 turned out to be a homoeologous wheat-H. villosa chromosome translocation line rather than a substitution. The translocation in Sub 6V-1 occurred between a wheat chromosome and a chromosome from H. villosa through Robertsonian fusion of misdivided centromeres. Only the short arm of the group 6 chromosome of H. villosa was involved in the genetic control of mite resistance, a conclusion based on the genomic in situ hybridization signal and specific DNA fragments obtained by polymerase chain reaction. PMID:24162394

Chen, Q; Conner, R L; Laroche, A

1996-10-01

299

Tillage and herbicides impact on weed control and wheat yield under rice–wheat cropping system in Northwestern Pakistan  

Microsoft Academic Search

Wheat (Triticum aestivum L.) production is low in rice (Oryza sativa L.)–wheat cropping system in the low-precipitation zone of Dera Ismail Khan, Pakistan. A 2 years field experiment was conducted during 2007–2009 to evaluate the effect of tillage systems and herbicides on weed control efficiency (WCE) and wheat yield under rice–wheat cropping system. Three tillage systems, zero tillage (ZT), reduced

Khalid Usman; Shad Khan Khalil; Amir Zaman Khan; Iftikhar Hussain Khalil; Muhammad Azim Khan; Amanullah

2010-01-01

300

The use of wheat-alien and Aegilops-rye amphiploids for introgression of genetic material to wheat  

Microsoft Academic Search

An introduction of genetic material from rye, Aegilops and Elymus into durum and common wheat by crossing the wheat species\\u000a with different amphiploids, has been attempted. Meiotic studies of the hybrids demonstrated that the wheat Elymus sibiricus\\u000a amphiploid contained several (two or three) genes suppressing the activity of the wheat homoeologous pairing control system.\\u000a Somatic chromosome studies of the hybrids

V. K. Simonenko; I. I. Motsny; A. L. Sechnyak; M. P. Kulbida

1998-01-01

301

Carbohydrate composition of wheat, wheat bran, sorghum and bajra with good chapati\\/roti (Indian flat bread) making quality  

Microsoft Academic Search

Varieties of wheat, sorghum and bajra having good chapati\\/roti making quality were studied for carbohydrate profile. Polysaccharide fractions (water-soluble, barium hydroxide-soluble, alkali-soluble and insoluble) were isolated from these cereals and wheat bran and their carbohydrate profiles were studied. Arabinoxylans were the major polysaccharides, other than starch and cellulose. The ratio of arabinose to xylose in whole-wheat flour and wheat bran

Chilkunda D Nandini; Paramahans V Salimath

2001-01-01

302

Comparative investigations of gluten proteins from different wheat speciesII. Characterization of ?-gliadins  

Microsoft Academic Search

Flours of different wheat species (common wheats including winter wheat, spring wheat, and wheat rye hybrid, spelt, durum\\u000a wheat, emmer, and einkorn) were successively extracted with a salt solution and 60% (v\\/v) aqueous ethanol. The alcohol extracts\\u000a (gliadins) were separated by reversed-phase HPLC. Six to nine different ?-gliadins were obtained for each wheat sample and\\u000a were characterized by their relative

W. Seilmeier; I. Valdez; E. Mendez; H. Wieser

2001-01-01

303

Causes for improvement in nutritive value of broiler chicken diets with whole wheat instead of ground wheat  

Microsoft Academic Search

1. Two experiments were conducted with broiler chicks to compare nutritive values of ground and whole wheat diets containing titanium oxide as indigestible marker.2. In Experiment 1, a wheat and soy isolate based cold-pelleted diet, in which all the wheat was ground in a hammer mill to pass through a 3?mm sieve, was compared with a diet in which about

B. Svihus; E. Juvik; H. Hetland; Å. Krogdahl

2004-01-01

304

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

305

[Umbilical cord hematopoietic progenitor cells bank].  

PubMed

Transplantation of hematopoietic progenitor cells (HPC) from bone marrow and mobilized peripheral blood is a standard therapy in malignant and non malignant diseases. The lack of suitable donors is an important limitation. The discovery that umbilical cord blood (CB) contains high numbers of HPC that can be used as an alternative source for allogeneic stem cell transplantation led ITMO to establish BANCEL, the first Argentine and Latinoamerican experience of its kind. The blood remaining in the umbilical cord and in the placenta was requested from women who were in the last quarter of pregnancy. An informed consent together with a medical record focused on family disease was completed. Out of 65 donations, 55 (85%) were collected and 51 (78%) were cryopreserved. Mean collected volume was 110 ml with 68% (75 ml) reduction and mean cryopreservation of 35 ml; ABO and Rh blood group systems were determined, HLA, class I, A and B loci, and class II, DR locus were typed by molecular biology methods using PCR-SSOP. Infectious disease screening was carried out for brucellosis, syphilis, Chagas, hepatitis B and C, HIV I and II, HTLV I and II, toxoplasmosis and cytomegalovirus. Two positive units for hepatitis B (anticore) and two positive units for Chagas were discarded. The quantity of total nucleated cells (TNC), CD34+ cells and the clonogenic capacity were determined twice at the collection and after the procedures of volume reduction previous to cryopreservation. A 5% reduction in both TNC and CD34 cells and a 10% in the colony forming units (CFU) were detected. A good correlation coefficient between TNC and CFU was obtained. PMID:11808425

Morales, V H; Milone, J; Etchegoyen, O; Bordone, J; Uranga, A

2001-01-01

306

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

307

Endothelial progenitor cells in diabetic retinopathy.  

PubMed

Diabetic retinopathy (DR) is a leading cause of visual impairment worldwide. Patients with DR may irreversibly lose sight as a result of the development of diabetic macular edema (DME) and/or proliferative diabetic retinopathy (PDR); retinal blood vessel dysfunction and degeneration plays an essential role in their pathogenesis. Although new treatments have been recently introduced for DME, including intravitreal vascular endothelial growth factor inhibitors (anti-VEGFs) and steroids, a high proportion of patients (~40-50%) do not respond to these therapies. Furthermore, for people with PDR, laser photocoagulation remains a mainstay therapy despite this being an inherently destructive procedure. Endothelial progenitor cells (EPCs) are a low-frequency population of circulating cells known to be recruited to sites of vessel damage and tissue ischemia where they promote vascular healing and re-perfusion. A growing body of evidence suggests that the number and function of EPCs are altered in patients with varying degrees of diabetes duration, metabolic control, and in the presence or absence of DR. Although there are no clear-cut outcomes from these clinical studies, there is mounting evidence that some EPC sub-types may be involved in the pathogenesis of DR and may also serve as biomarkers for disease progression and stratification. Moreover, some EPC sub-types have considerable potential as therapeutic modalities for DME and PDR in the context of cell therapy. This study presents basic clinical concepts of DR and combines this with a general insight on EPCs and their relation to future directions in understanding and treating this important diabetic complication. PMID:24782825

Lois, Noemi; McCarter, Rachel V; O'Neill, Christina; Medina, Reinhold J; Stitt, Alan W

2014-01-01

308

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

2013-09-01

309

Tolerance to Imidazolinone Herbicides in Wheat  

PubMed Central

An imidazolinone-tolerant wheat (Triticum aestivum L. em Thell) mutant in the winter wheat cultivar Fidel has been identified and characterized. The mutant was isolated from a population derived through seed mutagenesis of the variety with an aqueous solution containing sodium azide. Imidazolinone-tolerant wheat seedlings were selected from the M2 generation of the population in the presence of imazethapyr herbicide and identified as herbicide-insensitive individuals. The trait is inherited as a single semidominant gene and confers high levels of tolerance to imazethapyr. Acetohydroxyacid synthase activity in extracts from imidazolinonetolerant plants was less inhibited by imazethapyr than the enzyme from the wild type. The herbicide-tolerant plants have a completely normal phenotype and display no negative effects on growth and yield in either the absence or presence of imazethapyr.

Newhouse, Keith E.; Smith, Wendy A.; Starrett, Mark A.; Schaefer, Thomas J.; Singh, Bijay K.

1992-01-01

310

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

311

A Postnatal Pax7+ Progenitor Gives Rise to Pituitary Adenomas  

PubMed Central

Pituitary adenomas are classified into functioning and nonfunctioning (silent) tumors on the basis of hormone secretion. However, the mechanism of tumorigenesis and the cell of origin for pituitary adenoma subtypes remain to be elucidated. Employing a tamoxifen-inducible mouse model, we demonstrate that a novel postnatal Pax7+ progenitor cell population in the pituitary gland gives rise to silent corticotroph macro-adenomas when the retinoblastoma tumor suppressor is conditionally deleted. While Pax transcriptional factors are critical for embryonic patterning as well as postnatal stem cell renewal for many organs, we have discovered that Pax7 marks a restricted cell population in the postnatal pituitary intermediate lobe. This Pax7+ early progenitor cell population is overlapping but ontologically downstream of the Nestin+ pituitary stem cell population, yet upstream of another newly discovered Myf6+ late progenitor cell population. Interestingly, the Pax7+ progenitor cell population is evolutionarily conserved in primates and humans, and Pax7 expression is maintained not only in murine tumors but also in human functioning and silent corticotropinomas. Taken together, our results strongly suggest that human silent corticotroph adenomas may in fact arise from a Pax7 lineage of the intermediate lobe, a region of the human pituitary bearing closer scientific interest as a reservoir of pituitary progenitor cells.

Hosoyama, Tohru; Nishijo, Koichi; Garcia, Melinda M.; Schaffer, Beverly S.; Ohshima-Hosoyama, Sachiko; Prajapati, Suresh I.; Davis, Michael D.; Grant, Wilmon F.; Scheithauer, Bernd W.; Marks, Daniel L.; Rubin, Brian P.; Keller, Charles

2010-01-01

312

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

313

Isolation of EpCAM(+)/CD133 (-) hepatic progenitor cells.  

PubMed

Progenitor cell-derived hepatocytes are critical for hepatocyte replenishment. Therefore, we established a line of human hepatic progenitor (HNK1) cells and determined their biological characteristics for experimental and therapeutic applications. HNK1 cells, isolated from human noncirrhotic liver samples with septal fibrosis, showed high expression of the hepatic progenitor cell (HPC) markers EpCAM, CK7, CK19, alpha-fetoprotein (AFP), CD90 (Thy1), and EFNA1. Expression of CD133 was very low. Ductular reactions at the periphery of cirrhotic nodules were immunohistochemically positive for these HPC markers, including EFNA1. Sodium butyrate, a differentiation inducer, induced hepatocyte-like morphological changes in HNK1 cells. It resulted in down-regulation of the hepatic progenitor cell markers EpCAM, CK7, CK19, AFP, and EFNA1 and up-regulation of mature hepatocyte markers, including albumin, CK8, and CK18. Furthermore, sodium butyrate treatment and a serial passage of HNK1 cells resulted in enhanced albumin secretion, ureagenesis, and CYP enzyme activity, all of which are indicators of differentiation in hepatocytes. However, HNK1 cells at passage 50 did not exhibit anchorage-independent growth capability and caused no tumors in immunodeficient mice, suggesting that they had no spontaneous malignant transformation ability. From this evidence, HNK1 cells were found to be EpCAM(+)/CD133(-) hepatic progenitor cells without spontaneous malignant transformation ability. We therefore conclude that HNK1 cells could be useful for experimental and therapeutic applications. PMID:24293012

Hao, Pei-Pei; Lee, Mi-Jin; Yu, Goung-Ran; Kim, In-Hee; Cho, Yong-Gon; Kim, Dae-Ghon

2013-11-01

314

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

315

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

316

Transcriptome analysis of neural progenitor cells by a genetic dual reporter strategy  

PubMed Central

Global analysis of stem/progenitor cells promises new insight into mechanisms that govern self-renewal and cellular potential, an unresolved question of stem/progenitor cell biology. Despite rapid advance of genome-wide profiling methods, the difficulty in cell purification remains a major challenge for global analysis of somatic stem/progenitor cells. Genetic tagging with a reporter provides a powerful tool for identification and isolation of a specific mature cell type, however, for stem/progenitor cells, reporter retention by progeny may be a concern for impurity. Here we describe a genetic system combining a progenitor cell specific label with a second tag for marking differentiation. We present evidence that differential labeling of neural progenitor cells and their progeny enables prospective purification of these two cell types, whereas isolation based on a single marker compromises the purity of the intended progenitor population. Comparative expression profiling between the purified progenitors and progeny documents a neural progenitor cell transcriptome and uncovers an important role of TAM receptor tyrosine kinases in the maintenance of neural progenitor cells. This study establishes a general strategy for isolation of somatic stem/progenitor cells and provides a transcriptome database of neural progenitor cells useful for identification of causal factors of neural progenitor cell state, global dissection of epigenetic control of cellular potential, as well as for developing biomarkers or targets of brain cancer stem/initiating cells for therapeutic interventions.

Wang, Jun; Zhang, Heying; Young, Amanda G.; Qiu, Runxiang; Argalian, Siranush; Li, Xuejun; Wu, Xiwei; Lemke, Greg; Lu, Qiang

2012-01-01

317

Wheat productivity estimates using LANDSAT data  

NASA Technical Reports Server (NTRS)

The author has identified the following significant results. Large area LANDSAT yield estimates were generated. These results were compared with estimates computed using a meteorological yield model (CCEA). Both of these estimates were compared with Kansas Crop and Livestock Reporting Service (KCLRS) estimates of yield, in an attempt to assess the relative and absolute accuracy of the LANDSAT and CCEA estimates. Results were inconclusive. A large area direct wheat prediction procedure was implemented. Initial results have produced a wheat production estimate comparable with the KCLRS estimate.

Nalepka, R. F.; Colwell, J. E. (principal investigators); Rice, D. P.; Bresnahan, P. A.

1977-01-01

318

Natural variation in grain composition of wheat and related cereals.  

PubMed

The wheat grain comprises three groups of major components, starch, protein, and cell wall polysaccharides (dietary fiber), and a range of minor components that may confer benefits to human health. Detailed analyses of dietary fiber and other bioactive components were carried out under the EU FP6 HEALTHGRAIN program on 150 bread wheat lines grown on a single site, 50 lines of other wheat species and other cereals grown on the same site, and 23-26 bread wheat lines grown in six environments. Principal component analysis allowed the 150 bread wheat lines to be classified on the basis of differences in their contents of bioactive components and wheat species (bread, durum, spelt, emmer, and einkorn wheats) to be clearly separated from related cereals (barley, rye, and oats). Such multivariate analyses could be used to define substantial equivalence when novel (including transgenic) cereals are considered. PMID:23414336

Shewry, Peter R; Hawkesford, Malcolm J; Piironen, Vieno; Lampi, Ann-Maija; Gebruers, Kurt; Boros, Danuta; Andersson, Annica A M; Åman, Per; Rakszegi, Mariann; Bedo, Zoltan; Ward, Jane L

2013-09-01

319

CXCR4 Expression in Prostate Cancer Progenitor Cells  

PubMed Central

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.

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.

2012-01-01

320

Neural progenitors, neurogenesis and the evolution of the neocortex.  

PubMed

The neocortex is the seat of higher cognitive functions and, in evolutionary terms, is the youngest part of the mammalian brain. Since its origin, the neocortex has expanded in several mammalian lineages, and this is particularly notable in humans. This expansion reflects an increase in the number of neocortical neurons, which is determined during development and primarily reflects the number of neurogenic divisions of distinct classes of neural progenitor cells. Consequently, the evolutionary expansion of the neocortex and the concomitant increase in the numbers of neurons produced during development entail interspecies differences in neural progenitor biology. Here, we review the diversity of neocortical neural progenitors, their interspecies variations and their roles in determining the evolutionary increase in neuron numbers and neocortex size. PMID:24866113

Florio, Marta; Huttner, Wieland B

2014-06-01

321

Establishment of bipotent progenitor cell clone from rat skeletal muscle.  

PubMed

The present study describes the isolation, cloning and characterization of adipogenic progenitor cells from rat skeletal muscle. Among the obtained 10 clones, the most highly adipogenic progenitor, 2G11 cells, were further characterized. In addition to their adipogenicity, 2G11 cells retain myogenic potential as revealed by formation of multinucleated myotubes when co-cultured with myoblasts. 2G11 cells were resistant to an inhibitory effect of basic fibroblast growth factor on adipogenesis, while adipogenesis of widely used preadipogenic cell line, 3T3-L1 cells, was suppressed almost completely by the same treatment. In vivo transplantation experiments revealed that 2G11 cells are able to possess both adipogenicity and myogenicity in vivo. These results indicate the presence of bipotent progenitor cells in rat skeletal muscle, and suggest that such cells may contribute to ectopic fat formation in skeletal muscle. PMID:22111633

Murakami, Yousuke; Yada, Erica; Nakano, Shin-ichi; Miyagoe-Suzuki, Yuko; Hosoyama, Tohru; Matsuwaki, Takashi; Yamanouchi, Keitaro; Nishihara, Masugi

2011-12-01

322

Transcriptome analysis identifies regulators of hematopoietic stem and progenitor cells.  

PubMed

Hematopoietic stem cells (HSCs) maintain blood homeostasis and are the functional units of bone marrow transplantation. To improve the molecular understanding of HSCs and their proximal progenitors, we performed transcriptome analysis within the context of the ImmGen Consortium data set. Gene sets that define steady-state and mobilized HSCs, as well as hematopoietic stem and progenitor cells (HSPCs), were determined. Genes involved in transcriptional regulation, including a group of putative transcriptional repressors, were identified in multipotent progenitors and HSCs. Proximal promoter analyses combined with ImmGen module analysis identified candidate regulators of HSCs. Enforced expression of one predicted regulator, Hlf, in diverse HSPC subsets led to extensive self-renewal activity ex vivo. These analyses reveal unique insights into the mechanisms that control the core properties of HSPCs. PMID:24319662

Gazit, Roi; Garrison, Brian S; Rao, Tata Nageswara; Shay, Tal; Costello, James; Ericson, Jeff; Kim, Francis; Collins, James J; Regev, Aviv; Wagers, Amy J; Rossi, Derrick J

2013-01-01

323

3D GRB Jets Drilling Through The Progenitor  

NASA Astrophysics Data System (ADS)

We present, for the first time, three dimensional (3D) adaptive mesh refinement simulations of a GRB jet crossing a pre-SN progenitor (with resolutions comparable to the resolutions of 2D simulations) (Lopez-Camara et al. 2012). The morphology, Lorentz factor, and symmetries, will be discussed in this presentation. Basically the evolution is divided into three main phases: the jet moving inside the progenitor; the jet just about break out of the progenitor; and the phase where the jet has broken out of the star and is now moving through the circumstellar medium. The resolution and 3D effects are also discussed. Still, as with all numerical work, the current investigation lacks in several aspects and needs improvement as well as further investigations.

López-Cámara, D.

2013-07-01

324

Transcriptome Analysis Identifies Regulators of Hematopoietic Stem and Progenitor Cells  

PubMed Central

Summary Hematopoietic stem cells (HSCs) maintain blood homeostasis and are the functional units of bone marrow transplantation. To improve the molecular understanding of HSCs and their proximal progenitors, we performed transcriptome analysis within the context of the ImmGen Consortium data set. Gene sets that define steady-state and mobilized HSCs, as well as hematopoietic stem and progenitor cells (HSPCs), were determined. Genes involved in transcriptional regulation, including a group of putative transcriptional repressors, were identified in multipotent progenitors and HSCs. Proximal promoter analyses combined with ImmGen module analysis identified candidate regulators of HSCs. Enforced expression of one predicted regulator, Hlf, in diverse HSPC subsets led to extensive self-renewal activity ex vivo. These analyses reveal unique insights into the mechanisms that control the core properties of HSPCs.

Gazit, Roi; Garrison, Brian S.; Rao, Tata Nageswara; Shay, Tal; Costello, James; Ericson, Jeff; Kim, Francis; Collins, James J.; Regev, Aviv; Wagers, Amy J.; Rossi, Derrick J.

2013-01-01

325

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

326

Decreased quality of peripheral blood progenitors collected after a peripheral blood progenitor transplant.  

PubMed

The purpose of this study was to determine the quality of peripheral blood progenitor cells (PBPC) collected after an initial autologous PBPC transplant. Tandem autologous transplants have been used in the treatment of several malignancies. Routinely, PBPC have been collected prior to the first transplant and used for both transplants. In the current study, PBPC harvested prior to the first high-dose therapy (HDT) were used as a source of progenitors for transplant 1, and a combination of bone marrow harvested prior to the first course of HDT and PBPC collected approximately 85 days after the first transplant were used to support the second HDT. We analyzed the quality of the PBPC collected 85-120 days after HDT and autologous PBPC transplant. CD34 and colony-forming units granulocyte-macrophage (CFU-GM) contents of those collections were poor, and hematopoietic recovery was more consistent with recovery from a bone marrow transplant than a PBPC transplant. Thirteen of 15 patients received both transplants. Days to absolute granulocyte count of 500 was 10 +/- 1.5 for the first transplant and 13.3 +/- 3.7 for the second (p < 0.01). The number of days to platelet count of 20,000 was 14.3 +/- 10.7 for the first transplant and 18 +/- 7 for the second transplant (p = 0.066). The number of days of total parenteral nutrition (TPN) and intravenous morphine used by patients for the first and second transplants was similar, whereas the length of hospitalization was 21.8 +/- 3.6 for the first transplant and 27.6 +/- 7.8 for the second transplant (NS). In conclusion, it appears that the quality of PBPC collected following a previous PBPC transplant may be compromised. PMID:10982245

Miller, A; Morrison, D; Safah, H; Cullins, S; Larussa, V; Rink, J; Weiner, R

2000-08-01

327

On-farm impacts of zero tillage wheat in South Asia's rice–wheat systems  

Microsoft Academic Search

The recent slow down in productivity growth in the irrigated areas of the Indo-Gangetic Plains of South Asia has led to a quest for resource-conserving technologies that can reduce production costs, save water and improve production. Findings from farm surveys are used to evaluate the on-farm impacts of zero tillage (ZT) wheat in the rice–wheat systems of India's Haryana state

Olaf Erenstein; Umar Farooq; R. K. Malik; Muhammad Sharif

2008-01-01

328

Characterization of ?-gliadin genes from diploid wheats and the comparative analysis with those from polyploid wheats  

Microsoft Academic Search

To carry out comparative analysis of the ?-gliadin genes on A genomes of diploid and polyploid wheats, 8 full-length ?-gliadin\\u000a genes, including 3 functional genes and 5 pseudogenes, were obtained from diploid wheats, among which 2, 2 and 4 ?-gliadin\\u000a genes were isolated from T. urartu, T. monococcum, and T. boeoticum, respectively. The results indicated that higher number of ?-gliadin

Z.-C. Ma; Y.-M. Wei; Z.-H. Yan; Y.-L. Zheng

2007-01-01

329

Selenium distribution in wheat grain, and the effect of postharvest processing on wheat selenium content  

Microsoft Academic Search

Selenium (Se) is an essential micronutrient for animals and humans, and wheat is a major dietary source of this element. It\\u000a is improtant that postharvest processing losses of grain Se are minimized. This study, using grain dissection, milling with\\u000a a Quadrumat mill, and baking and toasting studies, investigated the distribution of Se and other mineral nutrients in wheat\\u000a grain and

Graham H. Lyons; Yusuf Genc; James C. R. Stangoulis; Lyndon T. Palmer; Robin D. Graham

2005-01-01

330

Hematopoietic stem cell and progenitor cell mechanisms in myelodysplastic syndromes.  

PubMed

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. PMID:23388639

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

2013-02-19

331

Domestication and Crop Physiology: Roots of Green-Revolution Wheat  

PubMed Central

Background and Aims Most plant scientists, in contrast to animal scientists, study only half the organism, namely above-ground stems, leaves, flowers and fruits, and neglect below-ground roots. Yet all acknowledge roots are important for anchorage, water and nutrient uptake, and presumably components of yield. This paper investigates the relationship between domestication, and the root systems of landraces, and the parents of early, mid- and late green-revolution bread wheat cultivars. It compares the root system of bread wheat and ‘Veery’-type wheat containing the 1RS translocation from rye. Methods Wheat germplasm was grown in large pots in sand culture in replicated experiments. This allowed roots to be washed free to study root characters. Key Results The three bread wheat parents of early green-revolution wheats have root biomass less than two-thirds the mean of some landrace wheats. Crossing early green-revolution wheat to an F2 of ‘Norin 10’ and ‘Brevor’, further reduced root biomass in mid-generation semi-dwarf and dwarf wheats. Later-generation semi-dwarf wheats show genetic variation for root biomass, but some exhibit further reduction in root size. This is so for some California and UK wheats. The wheat–rye translocation in ‘Kavkaz’ for the short arm of chromosome 1 (1RS) increased root biomass and branching in cultivars that contained it. Conclusions Root size of modern cultivars is small compared with that of landraces. Their root system may be too small for optimum uptake of water and nutrients and maximum grain yield. Optimum root size for grain yield has not been investigated in wheat or most crop plants. Use of 1RS and similar alien translocations may increase root biomass and grain yield significantly in irrigated and rain-fed conditions. Root characters may be integrated into components of yield analysis in wheat. Plant breeders may need to select directly for root characters.

Waines, J. Giles; Ehdaie, Bahman

2007-01-01

332

Thermonuclear supernova light curves: Progenitors and cosmology  

NASA Astrophysics Data System (ADS)

Thermonuclear Supernovae (TN SNe) are an extremely important tool in modern astronomy. In their role as cosmological distance probes, they have revealed the accelerated expansion of the universe and have begun to constrain the nature of the dark energy that may be driving that expansion. The next decade will see a succession of wide-field surveys producing thousands of TNSN detections each year. Traditional methods of SN analysis, rooted in time-intensive spectroscopic follow-up, will become completely impractical. To realize the potential of this coming tide of massive data sets, we will need to extract cosmographic parameters (redshift and luminosity distance) from SN photometry without any spectroscopic support. In this dissertation, I present the Supernova Ontology with Fuzzy Templates (SOFT) method, an innovative new approach to the analysis of SN light curves. SOFT uses the framework of fuzzy set theory to perform direct comparisons of SN candidates against template light curves, simultaneously producing both classifications and cosmological parameter estimates. The SOFT method allows us to shed new light on two rich archival data sets. I revisit the IfA Deep Survey and HST GOODS to extract new and improved measurements of the TNSN rate from z=0.2 out to z=1.6. Our new analysis shows a steady increase in the TNSN rate out to z˜1, and adds support for a decrease in the rate at z=1.5. Comparing these rate measurements to theoretical models, I conclude that the progenitor scenario most favored by the collective observational data is a single degenerate model, regulated by a strong wind from the accreting white dwarf. Using a compilation of SN light curves from five recent surveys, I demonstrate that SOFT is able to derive useful constraints on cosmological models from a data set with no spectroscopic information at all. Looking ahead to the near future, I find that photometric analysis of data sets containing 2,000 SNe will be able to improve our constraints on dark energy models by a factor of 2. With 10,000 objects we can realize an improvement of more than 5-fold over current limits.

Rodney, Steven A.

333

Enrichment and terminal differentiation of striated muscle progenitors in vitro  

SciTech Connect

Enrichment and terminal differentiation of mammalian striated muscle cells is severely hampered by fibroblast overgrowth, de-differentiation and/or lack of functional differentiation. Herein we report a new, reproducible and simple method to enrich and terminally differentiate muscle stem cells and progenitors from mice and humans. We show that a single gamma irradiation of muscle cells induces their massive differentiation into structurally and functionally intact myotubes and cardiomyocytes and that these cells can be kept in culture for many weeks. Similar results are also obtained when treating skeletal muscle-derived stem cells and progenitors with Mitomycin C.

Becher, Ulrich M.; Breitbach, Martin; Sasse, Philipp [Institute of Physiology I, Life and Brain Center, University of Bonn, Bonn (Germany)] [Institute of Physiology I, Life and Brain Center, University of Bonn, Bonn (Germany); Garbe, Stephan [Department of Radiology, University of Bonn, Bonn (Germany)] [Department of Radiology, University of Bonn, Bonn (Germany); Ven, Peter F.M. van der [Institute for Cell Biology, University of Bonn, Bonn (Germany); Fuerst, Dieter O., E-mail: dfuerst@uni-bonn.de [Institute for Cell Biology, University of Bonn, Bonn (Germany); Fleischmann, Bernd K., E-mail: bernd.fleischmann@uni-bonn.de [Institute of Physiology I, Life and Brain Center, University of Bonn, Bonn (Germany)

2009-10-01

334

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

335

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

2012-12-01

336

Impact of wheat-Leymus racemosus added chromosomes on wheat adaptation and tolerance to heat stress  

PubMed Central

Adaptation of wheat (Triticum aestivum L.) to high temperatures could be improved by introducing alien genes from wild relatives. We evaluated the responses of wheat-Leymus racemosus chromosome introgression lines to high temperature to determine their potentiality for developing improved wheat cultivars. Introgression lines and their parent Chinese Spring were evaluated in a growth chamber at the seedling stage and in the field at the reproductive stage in two heat-stressed environments in Sudan. Optimum and late planting were used to ensure exposure of the plants to heat stress at the reproductive stage. The results revealed the impact of several Leymus chromosomes in improving wheat adaptation and tolerance to heat. Three lines possessed enhanced adaptation, whereas two showed high heat tolerance. Two addition lines showed a large number of kernels per spike, while one possessed high yield potential. Grain yield was correlated negatively with the heat susceptibility index, days to heading and maturity and positively with kernel number per spike and triphenyl tetrazolium chloride assay under late planting. The findings suggest that these genetic stocks could be used as a bridge to introduce the valuable Leymus traits into a superior wheat genetic background, thus helping maximize wheat yield in heat-stressed environments.

Mohammed, Yasir Serag Alnor; Tahir, Izzat Sidahmed Ali; Kamal, Nasrein Mohamed; Eltayeb, Amin Elsadig; Ali, Abdelbagi Mukhtar; Tsujimoto, Hisashi

2014-01-01

337

Impact of wheat-Leymus racemosus added chromosomes on wheat adaptation and tolerance to heat stress.  

PubMed

Adaptation of wheat (Triticum aestivum L.) to high temperatures could be improved by introducing alien genes from wild relatives. We evaluated the responses of wheat-Leymus racemosus chromosome introgression lines to high temperature to determine their potentiality for developing improved wheat cultivars. Introgression lines and their parent Chinese Spring were evaluated in a growth chamber at the seedling stage and in the field at the reproductive stage in two heat-stressed environments in Sudan. Optimum and late planting were used to ensure exposure of the plants to heat stress at the reproductive stage. The results revealed the impact of several Leymus chromosomes in improving wheat adaptation and tolerance to heat. Three lines possessed enhanced adaptation, whereas two showed high heat tolerance. Two addition lines showed a large number of kernels per spike, while one possessed high yield potential. Grain yield was correlated negatively with the heat susceptibility index, days to heading and maturity and positively with kernel number per spike and triphenyl tetrazolium chloride assay under late planting. The findings suggest that these genetic stocks could be used as a bridge to introduce the valuable Leymus traits into a superior wheat genetic background, thus helping maximize wheat yield in heat-stressed environments. PMID:24757384

Mohammed, Yasir Serag Alnor; Tahir, Izzat Sidahmed Ali; Kamal, Nasrein Mohamed; Eltayeb, Amin Elsadig; Ali, Abdelbagi Mukhtar; Tsujimoto, Hisashi

2014-03-01

338

Genomic dissection of drought resistance in durum wheat x wild emmer wheat recombinant inbreed line population.  

PubMed

Drought is the major factor limiting wheat productivity worldwide. The gene pool of wild emmer wheat, Triticum turgidum ssp. dicoccoides, harbours a rich allelic repertoire for morpho-physiological traits conferring drought resistance. The genetic and physiological bases of drought responses were studied here in a tetraploid wheat population of 152 recombinant inbreed lines (RILs), derived from a cross between durum wheat (cv. Langdon) and wild emmer (acc# G18-16), under contrasting water availabilities. Wide genetic variation was found among RILs for all studied traits. A total of 110 quantitative trait loci (QTLs) were mapped for 11 traits, with LOD score range of 3.0-35.4. Several QTLs showed environmental specificity, accounting for productivity and related traits under water-limited (20 QTLs) or well-watered conditions (15 QTLs), and in terms of drought susceptibility index (22 QTLs). Major genomic regions controlling productivity and related traits were identified on chromosomes 2B, 4A, 5A and 7B. QTLs for productivity were associated with QTLs for drought-adaptive traits, suggesting the involvement of several strategies in wheat adaptation to drought stress. Fifteen pairs of QTLs for the same trait were mapped to seemingly homoeologous positions, reflecting synteny between the A and B genomes. The identified QTLs may facilitate the use of wild alleles for improvement of drought resistance in elite wheat cultivars. PMID:19220786

Peleg, Zvi; Fahima, Tzion; Krugman, Tamar; Abbo, Shahal; Yakir, Dan; Korol, Abraham B; Saranga, Yehoshua

2009-07-01

339

In search of tetraploid wheat accessions reduced in celiac disease-related gluten epitopes  

Microsoft Academic Search

Tetraploid wheat (durum wheat) is mainly used for the preparation of pasta. As a result of breeding, thousands of tetraploid wheat varieties exist, but also tetraploid landraces are still maintained and used for local food preparations. Gluten proteins present in wheat can induce celiac disease, a T-cell mediated auto-immune disorder, in genetically predisposed individuals after ingestion. Compared to hexaploid wheat,

Broeck van den H. C; Chen Hongbing; Xavier Lacaze; Jean-Claude Dusautoir; Ludovicus Gilissen; J. M. Smulders; Meer van der I. M

2010-01-01

340

Amino Acid Composition of Selected Strains of Diploid Wheat, Triticum monococcum L  

Microsoft Academic Search

Cereal Chem. 72(2):213-216 Diploid wheat (Triticum monococcum L., einkorn) is of interest both species of wheat and among diploid wheat strains were minimal, especially as a crop and as a source of genes unavailable in the more widely grown after amino acid values were adjusted to a common protein level. One wheat species, T. aestivum L. (common wheat) and T.

R. ACQUISTUCCI; M. G. D'EGIDIO; V. VALLEGA

341

Possible Progenitor of Special Supernova Type Detected  

NASA Astrophysics Data System (ADS)

Using data from NASA's Chandra X-ray Observatory, scientists have reported the possible detection of a binary star system that was later destroyed in a supernova explosion. The new method they used provides great future promise for finding the detailed origin of these important cosmic events. In an article appearing in the February 14th issue of the journal Nature, Rasmus Voss of the Max Planck Institute for Extraterrestrial Physics in Germany and Gijs Nelemans of Radboud University in the Netherlands searched Chandra images for evidence of a much sought after, but as yet unobserved binary system - one that was about to go supernova. Near the position of a recently detected supernova, they discovered an object in Chandra images taken more than four years before the explosion. Optical image of SN 2007on Optical image of SN 2007on The supernova, known as SN 2007on, was identified as a Type Ia supernova. Astronomers generally agree that Type Ia supernovas are produced by the explosion of a white dwarf star in a binary star system. However, the exact configuration and trigger for the explosion is unclear. Is the explosion caused by a collision between two white dwarfs, or because a white dwarf became unstable by pulling too much material off a companion star? Answering such questions is a high priority because Type Ia supernovas are major sources of iron in the Universe. Also, because of their nearly uniform intrinsic brightness, Type Ia supernova are used as important tools by scientists to study the nature of dark energy and other cosmological issues. People Who Read This Also Read... Oldest Known Objects Are Surprisingly Immature Black Holes Have Simple Feeding Habits Discovery of Most Recent Supernova in Our Galaxy Geriatric Pulsar Still Kicking "Right now these supernovas are used as black boxes to measure distances and derive the rate of expansion of the universe," said Nelemans. "What we're trying to do is look inside the box." If the supernova explosion is caused by material being pulled off a companion star onto the white dwarf, fusion of this material on the surface of the star should heat the star and produce a strong source of X-radiation prior to the explosion. Once the supernova explosion occurs, the white dwarf is expected to be completely destroyed and then would be undetectable in X-rays. In the merger scenario, the intensity of X-ray emission prior to the explosion is expected to be much weaker. Based on the detection of a fairly strong X-ray source at approximately the position of SN 2007on 4 years before the explosion, Voss and Nelemans conclude that the data support the scenario where matter is pulled off a companion star. The small number of X-ray sources in the field implies that there is only a small chance of an unrelated source being so close by coincidence. Also, the X-ray source has similar properties to those expected for fusion on a white dwarf, unlike most X-ray sources in the sky. However, in follow-up studies, Voss, Nelemans and colleagues Gijs Roelofs (Harvard-Smithsonian Center for Astrophysics, Cambridge, Mass.) and Cees Bassa (McGill University, Canada) used higher-quality optical images to better determine the supernova's position. This work, which is not yet published, shows a small, but significant difference in the measured positions of the supernova and the X-ray source, suggesting the source may not be the progenitor. Follow-up Chandra observations hint that the X-ray object has disappeared, but further observations are needed to finally decide whether the source was the progenitor or not. The team is also applying this new method to other supernovas and has high hopes that they will eventually succeed in identifying the elusive cause of at least some of these explosions. "We're very excited about opening up a new way of studying supernovas, even though we're not sure that we've seen this particular stellar bomb before it exploded," said Gijs Roelofs. "We're very confident that we'll learn a lot more about these important supernovas in the future.&

2008-04-01

342

Identification of wheat quality using THz spectrum.  

PubMed

The terahertz (THz) spectra in the range of 0.2-1.6 THz (6.6-52.8 cm-1) of wheat grains with various degrees of deterioration (normal, worm-eaten, moldy, and sprouting wheat grains) were investigated by terahertz time domain spectroscopy. Principal component analysis (PCA) was employed to extract feature data according to the cumulative contribution rates; the top four principal components were selected, and then a support vector machine (SVM) method was applied. Several selection kernels (linear, polynomial, and radial basis functions) were applied to identify the four types of wheat grain. The results showed that the materials were identified with an accuracy of nearly 95%. Furthermore, this approach was compared with others (principal component regression, partial least squares regression, and back-propagation neural networks). The comparisons showed that PCA-SVM outperformed the others and also indicated that the proposed method of THz technology combined with PCA-SVM is efficient and feasible for identifying wheat of different qualities. PMID:24921371

Ge, Hongyi; Jiang, Yuying; Xu, Zhaohui; Lian, Feiyu; Zhang, Yuan; Xia, Shanhong

2014-05-19

343

Bioremediation of Wheat Starch Media Waste.  

National Technical Information Service (NTIS)

The development of a bioremediation process is designed to minimize most of the waste generated with dry media paint removal. The bioremediation method was developed by DOT Technologies in Canada. When paint is removed with wheat starch media, a dust wast...

O. Malavallon J. Oestreich

1995-01-01

344

Foaming properties of enzymatically hydrolysed wheat gluten  

Microsoft Academic Search

A thermally treated wheat gluten (TTG) was structurally modified by enzymatic hydrolysis. Hydrolysis was carried out using a fungal protease. The solubility of hydrolysates having low, medium and high degrees of hydrolysis (DH) and the foaming properties of their extracts at each pH were determined. For comparison, a sample of TTG was used as a standard. The results showed that

S. R. Drago; R. J. González

2000-01-01

345

Phytochelatin and cadmium accumulation in wheat  

Microsoft Academic Search

Cadmium (Cd) is a nonessential heavy metal that can be harmful at low concentrations in organisms. Therefore, it is necessary to decrease Cd accumulation in the grains of wheats aimed for human consumption. In response to Cd, higher plants synthesize sulphur-rich peptides, phytochelatins (PCs). PC–heavy metal complexes have been reported to accumulate in the vacuole. Retention of Cd in the

J. P. Stolt; F. E. C. Sneller; T Bryngelsson; T. Lundborg; H. Schat

2003-01-01

346

I. Wheat seedling emergence under controlled climates  

Microsoft Academic Search

Experiments to determine the effects of the machinery and techniques used in creating direct-drilled seed grooves, and of covering the seeds, on wheat seed fate and soil physical characteristics are described. Comparisons were initially made in soils at either end of the available moisture range, and under contrasting controlled climatic conditions. Three coulter types were compared—an experimental chisel coulter, and

M. A. Choudhary; C. J. Baker

1980-01-01

347

Classification of wheat: Badhwar profile similarity technique  

NASA Technical Reports Server (NTRS)

The Badwar profile similarity classification technique used successfully for classification of corn was applied to spring wheat classifications. The software programs and the procedures used to generate full-scene classifications are presented, and numerical results of the acreage estimations are given.

Austin, W. W.

1980-01-01

348

Winter Wheat Fertilization: Post Ammonium Nitrate  

Microsoft Academic Search

Summary The potential for overwinter losses of nitrogen by denitrification and leaching have led to the recommendation that nitrogen fertilization of winter wheat be done using ammonium nitrate broadcast in the spring. However, spring broadcast application of urea can result in significant loss of nitrogen by volatilization and immobilization by surface residues. Since prilled ammonium nitrate is not available for

R. Byron Irvine; Guy Lafond; Randy Kutcher

349

Disulphide Bonds in Wheat Gluten Proteins  

Microsoft Academic Search

Disulphide bonds play a key role in determining the structure and properties of wheat gluten proteins. Comparison of the sequences of monomeric gliadins and polymeric glutenin subunits allows the identification of conserved and variant cysteine residues. Direct disulphide bond determination demonstrates that the conserved cysteine residues present in S-rich prolamins (?-type gliadins, ?-type gliadins and LMW subunits) form intra-chain disulphide

P. R. Shewry; A. S. Tatham

1997-01-01

350

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

351

Wheat: Situation and Outlook Yearbook, March 2007.  

National Technical Information Service (NTIS)

The projected 2006/07 season-average price received by farmers is $4.20 to $4.30 per bushel, sharply above last year's $3.42 per bushel due to the severe drought on the Great Plains and the run-up of corn prices late in 2006. Increased winter wheat planti...

E. Allen G. Vocke

2007-01-01

352

Tsarist Russia and the World Wheat Market  

Microsoft Academic Search

Russian grain trade, production, and consumption during the Tsarist period (1861–1914) is empirically evaluated. Russia was the world's largest wheat exporter during this period. Tsarist Russian agriculture is often characterized in the literature as having been “backward” and not well-integrated with international markets. In contrast to this view, this analysis finds that the Russian grain trade was significantly influenced by

Barry K. Goodwin; Thomas J. Grennes

1998-01-01

353

In vivo magnetic resonance imaging tracks adult neural progenitor cell targeting of brain tumor  

Microsoft Academic Search

Using magnetic resonance imaging (MRI), we described a method for noninvasively tracking grafted neural progenitor cells and bone marrow stromal cells (MSCs) in brain tumor of the rat. Neural progenitor cells and MSCs were labeled with lipophilic dye-coated superparamagnetic particles. The labeled neural progenitor cells and MSCs were transplanted to rats via the cisterna magna and a tail vein, respectively,

Zhenggang Zhang; Quan Jiang; Feng Jiang; Gaungliang Ding; Ruilan Zhang; Lei Wang; Li Zhang; Adam M. Robin; Mark Katakowski; Michael Chopp

2004-01-01

354

Mouse lung contains endothelial progenitors with high capacity to form blood and lymphatic vessels  

Microsoft Academic Search

BACKGROUND: Postnatal endothelial progenitor cells (EPCs) have been successfully isolated from whole bone marrow, blood and the walls of conduit vessels. They can, therefore, be classified into circulating and resident progenitor cells. The differentiation capacity of resident lung endothelial progenitor cells from mouse has not been evaluated. RESULTS: In an attempt to isolate differentiated mature endothelial cells from mouse lung

Judith Schniedermann; Moritz Rennecke; Kerstin Buttler; Georg Richter; Anna-Maria Städtler; Susanne Norgall; Muhammad Badar; Bernhard Barleon; Tobias May; Jörg Wilting; Herbert A Weich

2010-01-01

355

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

356

Clonogenic analysis of ciliary epithelial derived retinal progenitor cells in rabbits  

Microsoft Academic Search

In lower vertebrates, multipotential retinal stem cells reside in a far peripheral retinal zone known as the ciliary marginal zone while more fate-restricted progenitor cells are located immediately adjacent to this retinal margin. To determine whether mammalian ciliary epithelium contains heterogenous stem cell and progenitor cell populations similar to lower vertebrates, we investigated the heterogeneity of the retinal progenitor (or

Yuji Inoue; Yasuo Yanagi; Yasuhiro Tamaki; Saiko Uchida; Yoko Kawase; Makoto Araie; Hitoshi Okochi

2005-01-01

357

Type Ia supernovae: explosions and progenitors  

NASA Astrophysics Data System (ADS)

Supernovae are the brightest explosions in the universe. Supernovae in our Galaxy, rare and happening only every few centuries, have probably been observed since the beginnings of mankind. At first they were interpreted as religious omens but in the last half millennium they have increasingly been used to study the cosmos and our place in it. Tycho Brahe deduced from his observations of the famous supernova in 1572, that the stars, in contrast to the widely believe Aristotelian doctrine, were not immutable. More than 400 years after Tycho made his paradigm changing discovery using SN 1572, and some 60 years after supernovae had been identified as distant dying stars, two teams changed the view of the world again using supernovae. The found that the Universe was accelerating in its expansion, a conclusion that could most easily be explained if more than 70% of the Universe was some previously un-identified form of matter now often referred to as `Dark Energy'. Beyond their prominent role as tools to gauge our place in the Universe, supernovae themselves have been studied well over the past 75 years. We now know that there are two main physical causes of these cataclysmic events. One of these channels is the collapse of the core of a massive star. The observationally motivated classes Type II, Type Ib and Type Ic have been attributed to these events. This thesis, however is dedicated to the second group of supernovae, the thermonuclear explosions of degenerate carbon and oxygen rich material and lacking hydrogen - called Type Ia supernovae (SNe Ia). White dwarf stars are formed at the end of a typical star's life when nuclear burning ceases in the core, the outer envelope is ejected, with the degenerate core typically cooling for eternity. Theory predicts that such stars will self ignite when close to 1.38 Msun (called the Chandrasekhar Mass). Most stars however leave white dwarfs with 0.6 Msun, and no star leaves a remnant as heavy as 1.38 M! sun, which suggests that they somehow need to acquire mass if they are to explode as SN Ia. Currently there are two major scenarios for this mass acquisition. In the favoured single degenerate scenario the white dwarf accretes matter from a companion star which is much younger in its evolutionary state. The less favoured double degenerate scenario sees the merger of two white dwarfs (with a total combined mass of more than 1.38 Msun). This thesis has tried to answer the question about the mass acquisition in two ways. First the single degenerate scenario predicts a surviving companion post-explosion. We undertook an observational campaign to find this companion in two ancient supernovae (SN 1572 and SN 1006). Secondly, we have extended an existing code to extract the elemental and energy yields of SNe Ia spectra by automating spectra fitting to specific SNe Ia. This type of analysis, in turn, help diagnose to which of the two major progenitor scenarios is right.

Kerzendorf, Wolfgang Eitel

2011-08-01

358

Gene therapy of experimental brain tumors using neural progenitor cells  

Microsoft Academic Search

Glioblastomas, the most frequent and malignant of primary brain tumors, have a very poor prognosis. Gene therapy of glioblastomas is limited by the short survival of viral vectors and by their difficulty in reaching glioblastoma cells infiltrating the brain parenchyma. Neural stem\\/progenitor cells can be engineered to produce therapeutic molecules and have the potential to overcome these limitations because they

Sara Benedetti; Barbara Pirola; Bianca Pollo; Lorenzo Magrassi; Maria Grazia Bruzzone; Dorotea Rigamonti; Rossella Galli; Silvia Selleri; Francesco Di Meco; Claudio De Fraja; Angelo Vescovi; Elena Cattaneo; Gaetano Finocchiaro

2000-01-01

359

Hidden progenitors replace microglia in the adult brain.  

PubMed

Microglia are highly dynamic components of the innate immune system. In this issue of Neuron, Elmore et al. (2014) report that global depletion of microglia triggers mobilization of latent microglial progenitors throughout the CNS, resulting in rapid repopulation. PMID:24742453

Hughes, Ethan G; Bergles, Dwight E

2014-04-16

360

Endothelial progenitor cells display clonal restriction in multiple myeloma  

Microsoft Academic Search

BACKGROUND: In multiple myeloma (MM), increased neoangiogenesis contributes to tumor growth and disease progression. Increased levels of endothelial progenitor cells (EPCs) contribute to neoangiogenesis in MM, and, importantly, covary with disease activity and response to treatment. In order to understand the mechanisms responsible for increased EPC levels and neoangiogenic function in MM, we investigated whether these cells were clonal by

Marc Braunstein; Tayfun Özçelik; Sevgi Ba?i?lar; Varsha Vakil; Eric LP Smith; Kezhi Dai; Cemaliye B Akyerli; Olcay A Batuman

2006-01-01

361

Bovine Mammary Progenitor Cells: Current Concepts and Future Directions  

Microsoft Academic Search

Although cell number is positively correlated with milk production, much remains to be learned about the bovine mammary stem cell and progenitor cells. Bovine mammary development is driven by many of the same classic mammogenic hormones studied in murine models, yet histologic features of bovine mammary development differ from that of rodent models. Most notably, terminal end buds, as they

A. V. Capuco; S. Ellis

2005-01-01

362

Endothelial progenitor cells in neovascularization of infarcted myocardium  

Microsoft Academic Search

Historically, revascularization of ischemic tissue was believed to occur through the migration and proliferation of endothelial cells in nearby tissues; however, evidence accumulated in recent years indicates that a subpopulation of adult, peripheral-blood cells, collectively referred to as endothelial progenitor cells (EPCs), can differentiate into mature endothelial cells. After ischemic insult, EPCs are believed to home to sites of neovascularization,

Kentaro Jujo; Masaaki Ii; Douglas W. Losordo

2008-01-01

363

Endothelial Progenitor Cells Dysfunction and Senescence: Contribution to Oxidative Stress  

Microsoft Academic Search

The identification of endothelial progenitor cells (EPCs) has led to a significant paradigm in the field of vascu- lar biology and opened a door to the development of new therapeutic approaches. Based on the current evidence, it ap- pears that EPCs may make both direct contribution to neovascularization and indirectly promote the angiogenic function of local endothelial cells via secretion

Toshio Imanishi; Hiroto Tsujioka; Takashi Akasaka

2008-01-01

364

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

365

Core-Collapse Supernova Progenitors in Hubble Space Telescope Images  

NASA Astrophysics Data System (ADS)

Determining which stars give rise to supernovae (SNe) is key to SN research and stellar evolution studies. Without knowledge of SN progenitors, many of the conclusions and inferences made about the connection between SNe and important problems in astrophysics stand on precarious ground. The main obstacle is that a SN leaves few traces of the star that exploded.

van Dyk, Schuyler D.; Li, Weidong; Filippenko, Alexei V.

366

Mobilization of stem and progenitor cells in cardiovascular diseases  

Microsoft Academic Search

Circulating bone marrow (BM)-derived stem and progenitor cells (SPCs) participate in turnover of vascular endothelium and myocardial repair after acute coronary syndromes. Acute myocardial infarction (MI) produces a generalized inflammatory reaction, including mobilization of SPCs, increased local production of chemoattractants in the ischemic myocardium, as well as neural and humoral signals activating the SPC egress from the BM. Several types

W Wojakowski; U Landmesser; R Bachowski; T Jadczyk; M Tendera

2012-01-01

367

Hyaluronan accumulates in demyelinated lesions and inhibits oligodendrocyte progenitor maturation  

Microsoft Academic Search

Demyelination is the hallmark of numerous neurodegenerative conditions, including multiple sclerosis. Oligodendrocyte progenitors (OPCs), which normally mature into myelin-forming oligodendrocytes, are typically present around demyelinated lesions but do not remyelinate affected axons. Here, we find that the glycosaminoglycan hyaluronan accumulates in demyelinated lesions from individuals with multiple sclerosis and in mice with experimental autoimmune encephalomyelitis. A high molecular weight (HMW)

Stephen A Back; Therese M F Tuohy; Hanqin Chen; Nicholas Wallingford; Andrew Craig; Jaime Struve; Ning Ling Luo; Fatima Banine; Ying Liu; Ansi Chang; Bruce D Trapp; Mahendra S Rao; Larry S Sherman

2005-01-01

368

?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

369

Applications of skeletal muscle progenitor cells for neuromuscular diseases.  

PubMed

Neuromuscular diseases affect skeletal muscle and/or nervous control resulting in direct disruption of skeletal muscle and muscle pathology, or nervous system disruption which indirectly disrupts muscle function. Stem cell-based therapy is well-recognized as a promising approach for several types of diseases including those affecting the neuromuscular system. To design a successful therapeutic strategy, it is important to choose the most appropriate stem cell type. Skeletal muscle progenitor cells (SMPCs), also called myogenic progenitors, can contribute to muscle regeneration, differentiate into skeletal muscles, and are valuable cells for therapeutic application. Different types of stem/progenitor cells, including satellite cells, side population cells, muscle derived stem cells, mesenchymal stem cells, myogenic pericytes, and mesoangioblasts, have been identified as possible cell resources of SMPCs. Furthermore, recent advances in stem cell biology allow us to use embryonic stem cells and induced pluripotent stem cells for SMPC derivation. When skeletal muscle is chosen as a target of cell transplantation, the possible criteria for choosing the "best" progenitor/stem cell include preparation strategies, efficiency of intramuscular integration, method of cellular delivery, and functional improvement of the muscle after cell transplantation. Here, we discuss recent findings on various types of SMPCs and their promise for future clinical translation in neuromuscular diseases. PMID:23671812

Hosoyama, Tohru; Van Dyke, Jonathan; Suzuki, Masatoshi

2012-01-01

370

A microfabricated scaffold for retinal progenitor cell grafting  

Microsoft Academic Search

Diseases that cause photoreceptor cell degeneration afflict millions of people, yet no restorative treatment exists for these blinding disorders. Replacement of photoreceptors using retinal progenitor cells (RPCs) represents a promising therapy for the treatment of retinal degeneration. Previous studies have demonstrated the ability of polymer scaffolds to increase significantly both the survival and differentiation of RPCs. We report the microfabrication

William L. Neeley; Stephen Redenti; Henry Klassen; Sarah Tao; Tejal Desai; Michael J. Young; Robert Langer

2008-01-01

371

Retrovirally mediated telomerase immortalization of neural progenitor cells  

Microsoft Academic Search

Traditional methods of generating immortalized lines of both somatic cells and their progenitors have relied on the use of oncogenes. However, the resulting lines are typically anaplastic in vitro and tumorigenic in vivo, and hence of limited utility. The overexpression of telomerase, as mediated by the induced overexpression of human telomerase reverse transcriptase (hTERT), has permitted the generation of stable,

Devin Chandler-Militello; Gang Lu; Su Wang; Neeta S Roy; Steven A Goldman

2007-01-01

372

Aging Is Associated with a Proapoptotic Endothelial Progenitor Cell Phenotype  

Microsoft Academic Search

The aim of this study was to determine if aging is associated with enhanced endothelial progenitor cell (EPC) sensitivity to apoptosis. Cells with phenotypic EPC characteristics were isolated from healthy, nonobese young (age 25 ± 1 years) and older (61 ± 1 years) men. Intracellular active caspase-3 concentrations in response to staurosporine stimulation were approximately 35% higher (p < 0.05)

Erich J. Kushner; Owen J. MacEneaney; Brian R. Weil; Jared J. Greiner; Brian L. Stauffer; Christopher A. DeSouza

2011-01-01

373

40 CFR 406.40 - Applicability; description of the bulgur wheat flour milling subcategory.  

Code of Federal Regulations, 2013 CFR

...Applicability; description of the bulgur wheat flour milling subcategory. 406.40 Section...MILLS POINT SOURCE CATEGORY Bulgur Wheat Flour Milling Subcategory § 406.40 Applicability; description of the bulgur wheat flour milling subcategory. The...

2013-07-01

374

40 CFR 406.30 - Applicability; description of the normal wheat flour milling subcategory.  

Code of Federal Regulations, 2013 CFR

...Applicability; description of the normal wheat flour milling subcategory. 406.30 Section...MILLS POINT SOURCE CATEGORY Normal Wheat Flour Milling Subcategory § 406.30 Applicability; description of the normal wheat flour milling subcategory. The...

2013-07-01

375

40 CFR 406.100 - Applicability; description of the wheat starch and gluten subcategory.  

Code of Federal Regulations, 2010 CFR

...Applicability; description of the wheat starch and gluten subcategory. 406.100 Section 406...POINT SOURCE CATEGORY Wheat Starch and Gluten Subcategory § 406.100 Applicability; description of the wheat starch and gluten subcategory. The provisions...

2010-07-01

376

40 CFR 406.100 - Applicability; description of the wheat starch and gluten subcategory.  

Code of Federal Regulations, 2013 CFR

...Applicability; description of the wheat starch and gluten subcategory. 406.100 Section 406...POINT SOURCE CATEGORY Wheat Starch and Gluten Subcategory § 406.100 Applicability; description of the wheat starch and gluten subcategory. The provisions...

2013-07-01

377

Causes for improvement in nutritive value of broiler chicken diets with whole wheat instead of ground wheat.  

PubMed

1. Two experiments were conducted with broiler chicks to compare nutritive values of ground and whole wheat diets containing titanium oxide as indigestible marker. 2. In Experiment 1, a wheat and soy isolate based cold-pelleted diet, in which all the wheat was ground in a hammer mill to pass through a 3 mm sieve, was compared with a diet in which about half (375 g/kg) of the ground wheat was taken out of the diet and supplied as whole wheat mixed into the diet after pelleting. 3. In Experiment 2, a diet based on ground wheat and soy isolate which was pelleted after preconditioning (final temperature 81 degrees C) was compared with a diet in which 500 g of the ground wheat was replaced by whole wheat mixed into the diet before pelleting. 4. In Experiment 1, replacement of ground wheat with whole wheat increased apparent metabolisable energy (AME) content and starch digestibility measured at ileal as well as faecal level, while weight gain and feed conversion efficiency (FCE) were not affected. Jejunal chyme showed increased amylase activity and bile salt concentration. 5. In Experiment 2, replacement of ground wheat with whole wheat increased dry matter content as well as bile content of gizzard, and stimulated an increase in gizzard as well as pancreas weight. Jejunal amylase and bile concentrations were not significantly affected and neither were growth, FCE or AME. 6. Results from this experiment indicate that the improved feed value sometimes observed with whole wheat may be associated with modulation of digestive processes resulting in increased pancreas and liver secretions. PMID:15115201

Svihus, B; Juvik, E; Hetland, H; Krogdahl, A

2004-02-01

378

[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

2013-01-01

379

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

380

Wheat Seed System in Ethiopia: Farmers' Varietal Perception, Seed Sources, and Seed Management  

Microsoft Academic Search

Knowledge and information on farmers' perception and its influence on adoption of modern wheat varieties, awareness and source of new wheat production technology, wheat seed sources, and on-farm seed-management practices remain sporadic in Ethiopia. This study was conducted to understand the functioning of the wheat seed system in four major wheat-growing areas of Ethiopia. A total of 304 wheat growers

Zewdie Bishaw; P. C. Struik; A. J. G Van Gastel

2010-01-01

381

Wheat flour based propionic acid fermentation: an economic approach.  

PubMed

A process for the fermentative production of propionic acid from whole wheat flour using starch and gluten as nutrients is presented. Hydrolysis of wheat flour starch using amylases was optimized. A batch fermentation of hydrolysate supplemented with various nitrogen sources using Propionibacterium acidipropionici NRRL B 3569 was performed. The maximum production of 48.61, 9.40, and 11.06 g of propionic acid, acetic acid and succinic acid, respectively, was found with wheat flour hydrolysate equivalent to 90 g/l glucose and supplemented with 15 g/l yeast extract. Further, replacement of yeast extract with wheat gluten hydrolysate showed utilization of gluten hydrolysate without compromising the yields and also improving the economics of the process. The process so developed could be useful for production of animal feed from whole wheat with in situ production of preservatives, and also suggest utilization of sprouted or germinated wheat for the production of organic acids. PMID:23357590

Kagliwal, Lalit D; Survase, Shrikant A; Singhal, Rekha S; Granström, Tom

2013-02-01

382

Is sequential feeding of whole wheat more efficient than ground wheat in laying hens?  

PubMed

The impact of sequential feeding of whole or ground wheat on the performance of layer hen was investigated using ISABROWN hens from 19 to 42 weeks of age. In addition, the effect of reduced dietary energy content of a complete diet was also investigated. Four treatments were tested. Whole wheat was alternated with a protein-mineral concentrate (balancer diet) in a treatment (sequential whole wheat: SWW), while another treatment alternated ground wheat (sequential ground wheat: SGW) with the same balancer diet. The control (C) was fed a complete layer diet conventionally. Another treatment (low energy: LE) was fed a complete diet conventionally. The diet contained lower energy (10.7 v. 11.6 MJ/kg) compared to the C. Each treatment was allocated 16 cages and each cage contained five birds. Light was provided 16 h daily (0400 to 2000 h). Feed offered was controlled (121 g/bird per day) and distributed twice (2 × 60.5 g) at 4 and 11 h after lights on. In the sequential treatment, only wheat (whole or ground) was fed during the first distribution and the balancer diet during the second distribution. Left over feed was always removed before the next distribution. The total feed intake was not different between SWW and SGW, but the two were lower than C (P < 0.05). Wheat intake was however, lowered with SGW compared to SWW (P < 0.05). Egg production and egg mass (EM) were not different between treatments. Egg weight was lower with SGW than with SWW (P < 0.05), but the two were similar to C. Body weight (BW) was lowered (P < 0.01) with SGW relative to SWW and C, SWW BW being also lower than the C one. The efficiency of egg production was increased (P < 0.01) with the SWW and SGW relative to the control. Birds fed LE had higher feed intake (P < 0.05) but they had similar egg production and EM compared to the two sequential treatments. The efficiency of feed utilization was also reduced (P < 0.01) with LE compared to SWW and SGW. It was concluded that sequential feeding is more efficient than conventional feeding. In addition, whole wheat appeared more efficient than ground wheat in terms of egg and BW. PMID:22440768

Umar Faruk, M; Bouvarel, I; Mallet, S; Ali, M N; Tukur, H M; Nys, Y; Lescoat, P

2011-02-01

383

miR-203 regulates progenitor cell proliferation during adult zebrafish retina regeneration.  

PubMed

Damage of the zebrafish retina triggers a spontaneous regeneration response that is initiated by Müller Glia (MG) dedifferentiation and asymmetric cell division to produce multipotent progenitor cells. Subsequent expansion of the progenitor pool by proliferation is critical for retina regeneration. Pax6b expression in the progenitor cells is necessary for their proliferation, but exact regulation of its expression is unclear. Here, we show that miR-203 is downregulated during regeneration in proliferating progenitor cells. Elevated miR-203 levels inhibit progenitor cell expansion without affecting MG dedifferentiation or progenitor cell generation. Using GFP-reporter assays and gain and loss of function experiments in the retina, we show that miR-203 expression must be suppressed to allow pax6b expression and subsequent progenitor cell proliferation. PMID:24858486

Rajaram, Kamya; Harding, Rachel L; Hyde, David R; Patton, James G

2014-08-15

384

Lyl1 regulates lymphoid specification and maintenance of early T lineage progenitors  

PubMed Central

Thymopoiesis depends on recruitment and expansion of bone marrow-derived progenitors, tight regulation of which is required to maintain T-lineage homeostasis. Lyl1, a transcription factor regulating hematopoietic progenitors, is expressed in thymocyte progenitors until T cell commitment. Here we demonstrate a requirement for Lyl1 in lymphoid specification and the maintenance of early T lineage progenitors (ETPs). Lyl1 deficiency resulted in profound defects in generation of lymphoid primed multipotent progenitors (LMPPs), common lymphoid progenitors (CLPs) and ETPs. Lyl1-deficient ETPs and DN2 thymocyte progenitors showed increased apoptosis, blocked differentiation and impaired expansion. We identified Gfi1 as a critical transcriptional target of Lyl1-mediated T-lymphopoiesis. Thus, Lyl1 is a pivotal component of a transcriptional program that controls lymphoid specification and maintenance of ETPs.

Zohren, Fabian; Souroullas, George P.; Luo, Min; Gerdemann, Ulrike; Imperato, Maria R.; Wilson, Nicola K.; Gottgens, Berthold; Lukov, Georgi L.; Goodell, Margaret A.

2012-01-01

385

Wheat BAX inhibitor-1 contributes to wheat resistance to Puccinia striiformis.  

PubMed

BAX inihibitor-1 (BI-1) is proposed to be a cell death suppressor conserved in both animals and plants. The ability of BI-1 genes to inhibit programmed cell death (PCD) has been well studied in animals, but the physiological importance of BI-1 in plant-microbe interactions remains unclear. This study characterized BI-1 from wheat infected by Puccinia striiformis f. sp. tritici (Pst). The deduced TaBI-1 protein contained a Bax inhibitor domain and seven transmembrane regions conserved among members of the BI-1 family. Transcription of TaBI-1 was detected in all wheat tissues tested (culms, roots, leaves, anthers, and spikelets). Furthermore, TaBI-1 exhibited positive transcriptional responses to Pst infection and abiotic stresses. Overexpression of TaBI-1 in tobacco blocked Bax-induced cell death. Silencing TaBI-1 in plants of a resistant wheat genotype converted a resistant reaction to a relatively susceptible reaction when inoculated with an avirulent pathotype of the pathogen, and increased the area per infection site, but the percentage of necrotic cells did not change significantly, indicating that TaBI-1, a negative cell death regulator, contributes to wheat resistance to stripe rust. These results provide a better understanding of the molecular mechanism of wheat resistance to stripe rust. PMID:22696283

Wang, Xiaojie; Tang, Chunlei; Huang, Xueling; Li, Fangfang; Chen, Xianming; Zhang, Gang; Sun, Yanfei; Han, Dejun; Kang, Zhensheng

2012-07-01

386

Cellulase production using different streams of wheat grain- and wheat straw-based ethanol processes.  

PubMed

Pretreatment is a necessary step in the biomass-to-ethanol conversion process. The side stream of the pretreatment step is the liquid fraction, also referred to as the hydrolyzate, which arises after the separation of the pretreated solid and is composed of valuable carbohydrates along with compounds that are potentially toxic to microbes (mainly furfural, acetic acid, and formic acid). The aim of our study was to utilize the liquid fraction from steam-exploded wheat straw as a carbon source for cellulase production by Trichoderma reesei RUT C30. Results showed that without detoxification, the fungus failed to utilize any dilution of the hydrolyzate; however, after a two-step detoxification process, it was able to grow on a fourfold dilution of the treated liquid fraction. Supplementation of the fourfold-diluted, treated liquid fraction with washed pretreated wheat straw or ground wheat grain led to enhanced cellulase (filter paper) activity. Produced enzymes were tested in hydrolysis of washed pretreated wheat straw. Supplementation with ground wheat grain provided a more efficient enzyme mixture for the hydrolysis by means of the near-doubled ?-glucosidase activity obtained. PMID:20734107

Gyalai-Korpos, Miklós; Mangel, Réka; Alvira, Pablo; Dienes, Dóra; Ballesteros, Mercedes; Réczey, Kati

2011-07-01

387

Hybrid breeding in wheat: technologies to improve hybrid wheat seed production.  

PubMed

Global food security demands the development and delivery of new technologies to increase and secure cereal production on finite arable land without increasing water and fertilizer use. There are several options for boosting wheat yields, but most offer only small yield increases. Wheat is an inbred plant, and hybrids hold the potential to deliver a major lift in yield and will open a wide range of new breeding opportunities. A series of technological advances are needed as a base for hybrid wheat programmes. These start with major changes in floral development and architecture to separate the sexes and force outcrossing. Male sterility provides the best method to block self-fertilization, and modifying the flower structure will enhance pollen access. The recent explosion in genomic resources and technologies provides new opportunities to overcome these limitations. This review outlines the problems with existing hybrid wheat breeding systems and explores molecular-based technologies that could improve the hybrid production system to reduce hybrid seed production costs, a prerequisite for a commercial hybrid wheat system. PMID:24179097

Whitford, Ryan; Fleury, Delphine; Reif, Jochen C; Garcia, Melissa; Okada, Takashi; Korzun, Viktor; Langridge, Peter

2013-12-01

388

Introgression of novel traits from a wild wheat relative improves drought adaptation in wheat.  

PubMed

Root architecture traits are an important component for improving water stress adaptation. However, selection for aboveground traits under favorable environments in modern cultivars may have led to an inadvertent loss of genes and novel alleles beneficial for adapting to environments with limited water. In this study, we elucidate the physiological and molecular consequences of introgressing an alien chromosome segment (7DL) from a wild wheat relative species (Agropyron elongatum) into cultivated wheat (Triticum aestivum). The wheat translocation line had improved water stress adaptation and higher root and shoot biomass compared with the control genotypes, which showed significant drops in root and shoot biomass during stress. Enhanced access to water due to higher root biomass enabled the translocation line to maintain more favorable gas-exchange and carbon assimilation levels relative to the wild-type wheat genotypes during water stress. Transcriptome analysis identified candidate genes associated with root development. Two of these candidate genes mapped to the site of translocation on chromosome 7DL based on single-feature polymorphism analysis. A brassinosteroid signaling pathway was predicted to be involved in the novel root responses observed in the A. elongatum translocation line, based on the coexpression-based gene network generated by seeding the network with the candidate genes. We present an effective and highly integrated approach that combines root phenotyping, whole-plant physiology, and functional genomics to discover novel root traits and the underlying genes from a wild related species to improve drought adaptation in cultivated wheat. PMID:23426195

Placido, Dante F; Campbell, Malachy T; Folsom, Jing J; Cui, Xinping; Kruger, Greg R; Baenziger, P Stephen; Walia, Harkamal

2013-04-01

389

Adult Hepatic Progenitor Cell Niche: How it affects the Progenitor Cell Fate  

PubMed Central

The hepatic progenitor cell (HPC) niche is a special microenvironment composed of different cell types, extracellular matrix (ECM) components, growth factors and cytokines released by the niche cells that help to maintain the characteristics of HPCs and the balance between their activation, proliferation and differentiation. Composition of this special microenvironment, created in response to specific liver damage, together with critical interactions between different partners of the HPC niche can determine the fate decision and differentiation pathways of HPCs. A number of recent studies have shed light on factors and signals from the HPC niche that determines the choice of HPCs differentiation towards a specific cell type depending on the nature of the liver injury and resultant microenvironment created by this injury. This paper seeks to provide an in-depth review, through a literature review and the authors’ experiences, of the most recent findings on the role of the HPC niche in fate choice option of HPCs toward either hepatocytes or bile duct epithelial cells and its clinical relevance.

Katoonizadeh, Aezam; Poustchi, Hossein

2014-01-01

390

Biochemical Characterization of Spring Wheats in Relation to Grain Hardness  

Microsoft Academic Search

Grain hardness is arguably the single most important determinant of wheat grain quality and utilization and forms the basis of differentiating world trade of wheat grain. The present study was carried out to determine the texture of spring wheats using starch granule-associated friabilin, a 15kDa protein, as biochemical marker and their relationship with other hardness methods, chemical and quality parameter.

Imran Pasha; Faqir Muhammad Anjum; Masood Sadiq Butt

2009-01-01

391

Effects of gamma-irradiation of wheat on gluten proteins  

Microsoft Academic Search

The effects of 60Co gamma-irradiation treatments (2·5, 5·0, 10·0 and 20·0 kGy) on the gluten proteins of two bread wheats and one durum wheat cultivar were investigated. Dough rheological properties of the flour processed from the irradiated wheat were also determined using a computerised micromixograph. Irradiation caused a significant deteriorating effect on all mixogram parameters. There was no observable effect

H. Köksel; H. D. Sapirstein; S. Çelik; W. Bushuk

1998-01-01

392

Diverse origins of aluminum-resistance sources in wheat  

Microsoft Academic Search

Aluminum (Al) toxicity is a major constraint for wheat production in acidic soils. Wheat producers now routinely use Al-resistant\\u000a cultivars as one cost-effective means to reduce risks associated with acidic soils. To date, diverse Al-resistant materials\\u000a have been identified, but their genetic relationship has not been well characterized. A total of 57 wheat accessions, including\\u000a the majority of the parents

Sheng-Wu Hu; Gui-Hua Bai; Brett F. Carver; Da-dong Zhang

2008-01-01

393

Research on Grading Detection of the Wheat Seeds  

PubMed Central

Evaluating the merits of the wheat seed is an important significance for wheat breeding. We studied analytic hierarchy process (AHP) for seeds grading by digital image processing techniques in the paper. Firstly, preprocess the collected wheat seed images; extract some parameters, such as area, plumpness, rectangular, and elongation of the seed, and then build the level model. Experiments showed the model is right, and level accuracy rate is more than 95%.

Han, Xian-Zhong; Wang, Ke-Jian; Yuan, Yingchun; Chen, Chen; Liang, Liang

2014-01-01

394

Virulence of Puccinia triticina on wheat in Iran  

Microsoft Academic Search

Wheat leaf rust is controlled mainly by race-specific resistance. To be effective, breeding wheat for resistance to leaf rust requires knowledge of virulence diversity in local populations of the pathogen. Collections of Puccinia triticina were made from rust-infected wheat leaves on the territory of Khuzestan province (south-west) in Iran during 2008 - 2009. In 2009, up to 20 isolates each

S. Elyasi-Gomari

395

Immunoreactivity and detection of wheat proteins by commercial ELISA kits.  

PubMed

Wheat proteins are responsible for sensitivities, including baker's asthma, immunoglobulin E (IgE)-mediated allergic reaction, wheat-dependent, exercise-induced anaphylaxis, and celiac disease. The detection of gluten/wheat traces in foods is important to safeguard the health of wheat-sensitive individuals and comply with food labeling. Many immunoanalytical-based commercial kits are available for the quantification of gliadin/gluten/wheat proteins. We compared the immunoreactivity of wheat fractions with wheat-allergic human serum IgE and antibody conjugates used in six commercial immunoassay kits. Moreover, the performance of the kits was tested using corn flour spiked with gluten (5, 10, 25, and 50 ppm) and wheat flour (50, 100, 250, and 500 ppm). The albumin, globulin, gliadin, and glutenin fractions reacted with IgE from nine, eight, two, and eight patients' sera, respectively, out of nine wheat allergic patients tested. Among the antibodies from commercial kits, those from R-Biopharm, Morinaga, and Romer Labs reacted strongly with the gliadin fraction, whereas those from BioKits, ALLER-TEK, and ELISA Systems reacted strongly with the glutenin fraction. All kits showed minimal or no reactivity with albumin and globulin fractions. All kits detected the gluten and wheat flour in a corn flour matrix at the lowest spiked levels of 5 and 50 ppm, respectively. However, there was wide variation among the kits when comparing the recovery of gluten and wheat flour. The recovery was also dependent on the source material (gluten or wheat flour) used for spiking the corn flour matrix. PMID:22649920

Sharma, Girdhari M

2012-01-01

396

Wheat Starch Intolerance in Patients With Celiac Disease  

Microsoft Academic Search

Objective Evaluate in patients with celiac disease the tolerance of prolonged consumption of small amounts of gliadin contained in products containing wheat starch. Design Open 1-year trial of the addition of wheat starch to a gluten-free diet in a cohort of adult patients with biopsy-proven celiac disease who had never consumed wheat starch. The control group consisted of patients with

LUCIE J CHARTRAND; PIERRE A RUSSO; ANNE G DUHAIME; ERNEST G SEIDMAN

1997-01-01

397

Current and Future Trends of Wheat Quality Needs  

Microsoft Academic Search

Wheat is one of the main sources of nutrients for humans and animals. Its wide adaptation to diverse agro-ecological conditions,\\u000a its storability, and its complex chemical composition, are main attributes that have made wheat the most widely used crop\\u000a in food processing. Wheat trading is vast, occurs world-wide, and is now more dynamic than ever. Present and predicted shifts\\u000a in

R. J. PEÑA

398

PROGENITOR-EXPLOSION CONNECTION AND REMNANT BIRTH MASSES FOR NEUTRINO-DRIVEN SUPERNOVAE OF IRON-CORE PROGENITORS  

SciTech Connect

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{sub Sun} 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 {approx}15 M{sub Sun} 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 {approx}1.2-2.0 M{sub Sun} and BH masses >6 M{sub Sun} are compatible with a possible lack of low-mass BHs in the empirical distribution. Neutrino heating accounts for SN energies between some 10{sup 50} erg and {approx}2 Multiplication-Sign 10{sup 51} erg but can hardly explain more energetic explosions and nickel masses higher than 0.1-0.2 M{sub Sun }. These seem to require an alternative SN mechanism.

Ugliano, Marcella; Janka, Hans-Thomas; Marek, Andreas [Max-Planck-Institut fuer Astrophysik, Karl-Schwarzschild-Str. 1, D-85748 Garching (Germany); Arcones, Almudena [Institut fuer Kernphysik, Technische Universitaet Darmstadt, Schlossgartenstr. 2, D-64289 Darmstadt (Germany)

2012-09-20

399

Butanol production by Clostridium beijerinckii ATCC 55025 from wheat bran  

Microsoft Academic Search

Wheat bran, a by-product of the wheat milling industry, consists mainly of hemicellulose, starch and protein. In this study,\\u000a the hydrolysate of wheat bran pretreated with dilute sulfuric acid was used as a substrate to produce ABE (acetone, butanol\\u000a and ethanol) using Clostridium beijerinckii ATCC 55025. The wheat bran hydrolysate contained 53.1 g\\/l total reducing sugars, including 21.3 g\\/l of glucose, 17.4 g\\/l

Ziyong Liu; Yu Ying; Fuli Li; Cuiqing Ma; Ping Xu

2010-01-01

400

Evaluation of trends in wheat yield models  

NASA Technical Reports Server (NTRS)

Trend terms in models for wheat yield in the U.S. Great Plains for the years 1932 to 1976 are evaluated. The subset of meteorological variables yielding the largest adjusted R(2) is selected using the method of leaps and bounds. Latent root regression is used to eliminate multicollinearities, and generalized ridge regression is used to introduce bias to provide stability in the data matrix. The regression model used provides for two trends in each of two models: a dependent model in which the trend line is piece-wise continuous, and an independent model in which the trend line is discontinuous at the year of the slope change. It was found that the trend lines best describing the wheat yields consisted of combinations of increasing, decreasing, and constant trend: four combinations for the dependent model and seven for the independent model.

Ferguson, M. C.

1982-01-01

401

Cation amelioration of aluminum toxicity in wheat  

Microsoft Academic Search

Aluminum is a major constituent of most soils and limits crop productivity in many regions. Amelioration is of theoretical as well as practical interest because understanding amelioration may contribute to an understanding of the mechanisms of toxicity. In the experiments reported here 2-day-old wheat (Triticum aestivum L. cv Tyler) seedlings with 15-millimeter roots were transferred to solutions containing 0.4 millimolar

T. B. Kinraide; D. R. Parker

1987-01-01

402

A recombinant wheat serpin with inhibitory activity  

Microsoft Academic Search

A full-length clone encoding the wheat (Triticum aestivum L.) serpin WSZ1 was isolated from a cDNA library based on mRNA from immature grain. The 398 amino acid sequence deduced from the cDNA was corroborated by sequencing CNBr peptides of WSZ1 purified from resting grain. WSZ1 belongs to the subfamily of protein Z-type serpins and the amino acid sequence is 70%

Søren K. Rasmussen; Søren W. Dahl; Anette Nørgård; Jørn Hejgaard

1996-01-01

403

Developmental studies on microbodies in wheat leaves  

Microsoft Academic Search

1.In etiolated wheat (Triticum aestivum L.) leaves, the development of the microbody enzymes catalase, hydroxypyruvate reductase, and glycolate oxidase was specifically stimulated by short treatments of the seedlings with red light, although the increases were less than observed after treatment with continuous white light. A comparison of the effects of short red and far-red exposures indicated the involvement of phytochrome.2.Continuous

J. Feierabend

1975-01-01

404

Inheritance of late maturity ?-amylase in wheat  

Microsoft Academic Search

Two wheat cultivars that consistently show high levels of grain a-amylase at harvest ripeness, in the absence of preharvest sprouting, were crossed with a control, low a-amylase cultivar, and F1, F2 and BC1 populations were developed. Grain of these populations was analysed for a-amylase activity at harvest ripeness. Distribution and segregation patterns were consistent with control at a single locus

Kolumbina Mrva; Daryl J. Mares

1996-01-01

405

Levulinic acid production from wheat straw  

Microsoft Academic Search

Studies were carried out on the effects of temperature, acid concentration, liquid:solid ratio and reaction time on levulinic acid production from wheat straw using response surface methodology. The P-value of the coefficient for acid concentration was 0.0002, suggesting that this was highly significant. The quadratic effects of temperature and liquid:solid ratio were also significant and their P-values were <0.0001 and

Chun Chang; Peilin Cen; Xiaojian Ma

2007-01-01

406

Genetics of tan spot resistance in wheat.  

PubMed

Tan spot is a devastating foliar disease of wheat caused by the necrotrophic fungal pathogen Pyrenophora tritici-repentis. Much has been learned during the past two decades about the genetics of wheat-P. tritici-repentis interactions. Research has shown that the fungus produces at least three host-selective toxins (HSTs), known as Ptr ToxA, Ptr ToxB, and Ptr ToxC, that interact directly or indirectly with the products of the dominant host genes Tsn1, Tsc2, and Tsc1, respectively. The recent cloning and characterization of Tsn1 provided strong evidence that the pathogen utilizes HSTs to subvert host resistance mechanisms to cause disease. However, in addition to host-HST interactions, broad-spectrum, race non-specific resistance QTLs and recessively inherited qualitative 'resistance' genes have been identified. Molecular markers suitable for marker-assisted selection against HST sensitivity genes and for race non-specific resistance QTLs have been developed and used to generate adapted germplasm with good levels of tan spot resistance. Future research is needed to identify novel HSTs and corresponding host sensitivity genes, determine if the recessively inherited resistance genes are HST insensitivities, extend the current race classification system to account for new HSTs, and determine the molecular basis of race non-specific resistance QTLs and their relationships with host-HST interactions at the molecular level. Necrotrophic pathogens such as P. tritici-repentis are likely to become increasingly significant under a changing global climate making it imperative to further characterize the wheat-P. tritici-repentis pathosystem and develop tan spot resistant wheat varieties. PMID:23884599

Faris, Justin D; Liu, Zhaohui; Xu, Steven S

2013-09-01

407

Explosion pulping of bagasse and wheat straw  

SciTech Connect

Bagasse and wheat straw were soda-pulped in a digester at 200 degrees under N pressure of up to 13.8 MPa, followed by explosive discharge through nozzles to give pulp having lower yield and higher initial freeness than batch soda pulp. Explosion pulping required less NaOH than conventional batch soda pulping, and the properties of explosion pulp obtained were similar to those of batch soda pulp at a given freeness.

Mamers, H.; Yuritta, J.P.; Menz, D.J.

1981-01-01

408

Phytostimulation and biofertilization in wheat by cyanobacteria  

Microsoft Academic Search

Cyanobacteria are commonly used for the phytostimulation and biofertilization of agriculture crops due to their nitrogen-fixing\\u000a ability. However, the contribution by their phytohormones has been neglected. This study focuses on the screening of rhizospheric\\u000a and free-living cyanobacteria for in vitro phytohormones production and growth stimulation in wheat. Selected isolates were\\u000a shown to release cytokinin and indole-3-acetic acid (IAA) by using

Anwar HussainShahida Hasnain; Shahida Hasnain

2011-01-01

409

Plasma-Assisted Pretreatment of Wheat Straw  

Microsoft Academic Search

O3 generated in a plasma at atmospheric pressure and room temperature, fed with dried air (or oxygen-enriched dried air), has\\u000a been used for the degradation of lignin in wheat straw to optimize the enzymatic hydrolysis and to get more fermentable sugars.\\u000a A fixed bed reactor was used combined with a CO2 detector and an online technique for O3 measurement in

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

2011-01-01

410

Iron fortification of wheat flour: bioavailability studies.  

PubMed

Bioavailability refers to that fraction of nutrients which is utilized by the body out of the total indigested amount. Various direct and indirect methods for the determination of bioavailability are available. We determined the bioavailability of iron from fortified wheat flour using both in vitro and in vivo methods. The bioavailability data will be used to make the recommendation for a fortification strategy in Pakistan. The in vitro bioavailability of iron from fortified wheat flour was determined using in vitro enzymatic digestion and fermentation by simulating the condition of the small intestine and colon in the laboratory. Different products were prepared from the fortified ferrous sulfate (FeSO4) and unfortified wheat flour. The total iron of the samples was measured by the wet-digestion method and analyzed on an atomic absorption spectrometer (AAS). To obtain the percentage of iron released, the samples were subjected to pepsin digestion and dialysis. The dialysate was collected at 3, 6, 9, and 12 hours and read on an AAS. The retentates from the above were subjected to the fermentation condition of the colon by inoculating it with human fecal inoculum and incubating it for 24 hours at 37 degrees C under anerobic conditions. The dialysate was collected at 3- and 6-hour intervals and read on an AAS. More iron was released from fortified wheat flour (4.6%), leavened chapati (6.8%), and Nan (15.1%) than from the unfortified control samples. Fermentation and leavening resulted in a better release, which was evident from in vitro digestion results. PMID:12362795

Bilal, Rakhshanda; Roohi, Samina; Ahmad, Tanvir; Trinidad, Trinidad P

2002-09-01

411

Genetic Diversity and Core Collection Evaluations in Common Wheat Germplasm from the Northwestern Spring Wheat Region in China  

Microsoft Academic Search

Fluorescence microsatellite markers were employed to reveal genetic diversity of 340 wheat accessions consisting of 229 landraces\\u000a and 111 modern varieties from the Northwest Spring Wheat Region in China. The 340 accessions were chosen as candidate core\\u000a collections for wheat germplasm in this region. A core collection representing the genetic diversity of these accessions was\\u000a identified based on a cluster

C. Y. Hao; X. Y. Zhang; L. F. Wang; Y. S. Dong; X. W. Shang; J. Z. Jia

2006-01-01

412

Soft Wheat Milling and Baking Quality in a Soft Red Winter X Hard Red Winter Wheat Population  

Microsoft Academic Search

Cereal Chem. 66(5):378-381 A single-cross soft red winter X hard red winter wheat population and high SE and adjusted flour yield, indicating acceptable preliminary was evaluated in the F3, F4, and F5 generations for preliminary soft red soft red winter wheat milling and baking quality. Narrow sense heritability winter wheat milling and baking quality. Tests conducted included the estimates for

L. MAY; D. A. VAN SANFORD; P. L. FINNEY

413

Detection and Discrimination of Wheat Spindle Streak Mosaic Virus and Wheat Yellow Mosaic Virus Using Multiplex RT-PCR  

Microsoft Academic Search

Wheat spindle streak mosaic virus (WSSMV) and wheat yellow mosaic virus (WYMV) are two closely related bymoviruses which cause significant yield losses in wheat. There is no molecular diagnostic protocol available for either virus nor are serological methods able to discriminate them. A multiplex reverse transcription-polymerase chain reaction (RT-PCR) protocol was developed for their detection and discrimination. Twenty-three isolates of

Gerard Clover; Christine Henry

1999-01-01

414

Adrenocortical Stem and Progenitor Cells--Implications for Adrenocortical Carcinoma  

PubMed Central

The continuous centripetal repopulation of the adrenal cortex is consistent with a population of cells endowed with the stem/progenitor cell properties of self-renewal and pluripotency. The adrenocortical capsule and underlying undifferentiated cortical cells are emerging as critical components of the stem/progenitor cell niche. Recent genetic analysis has identified various signaling pathways including Sonic Hedgehog (Shh) and Wnt as crucial mediators of adrenocortical lineage and organ homeostasis. Shh expression is restricted to the peripheral cortical cells that express a paucity of steroidogenic genes but give rise to the underlying differentiated cells of the cortex. Wnt/?-catenin signaling maintains the undifferentiated state and adrenal fate of adrenocortical stem/progenitor cells, in part through induction of its target genes Dax1 and inhibin-?, respectively. The pathogenesis of ACC, a rare yet highly aggressive cancer with an extremely poor prognosis, is slowly emerging from studies of the stem/progenitor cells of the adrenal cortex coupled with the genetics of familial syndromes in which ACC occurs. The frequent observation of constitutive activation of Wnt signaling due to loss-of-function mutations in the tumor suppressor gene APC or gain-of-function mutation in ?-catenin in both adenomas and carcinomas, suggests pe