Search Results - (Author, Cooperation:O. A. Olsen)

2014-07-19

American Association for the Advancement of Science (AAAS)

0036-8075

1095-9203

Biology

Chemistry and Pharmacology

Computer Science

Medicine

Natural Sciences in General

Physics

*Bread ; *Evolution, Molecular ; Genes, Plant ; *Genome, Plant ; *Hybridization, Genetic ; Phylogeny ; Polyploidy ; Triticum/classification/*genetics

2014-07-19

American Association for the Advancement of Science (AAAS)

0036-8075

1095-9203

Biology

Chemistry and Pharmacology

Computer Science

Medicine

Natural Sciences in General

Physics

*Bread ; Edible Grain/genetics ; Endosperm/genetics ; Gene Dosage ; Gene Expression Regulation, Plant ; *Genome, Plant ; Plant Proteins/genetics ; *Polyploidy ; Transcriptome ; Triticum/*genetics

2011-08-19

Nature Publishing Group (NPG)

0028-0836

1476-4687

Biology

Chemistry and Pharmacology

Medicine

Natural Sciences in General

Physics

AIDS Vaccines/biosynthesis/immunology ; Antibodies, Monoclonal/immunology ; Antibodies, Neutralizing/*immunology ; Cell Line ; Epitope Mapping ; Epitopes/chemistry/immunology ; Glycoproteins/chemistry/immunology ; Glycosylation ; HEK293 Cells ; HIV/*classification/*immunology/isolation & purification ; HIV Antibodies/*immunology ; HIV Infections/immunology/therapy ; Human Immunodeficiency Virus Proteins/chemistry/immunology ; Humans ; Immune Sera/blood/immunology ; Molecular Sequence Data ; Neutralization Tests

2018-08-17

American Association for the Advancement of Science (AAAS)

0036-8075

1095-9203

Biology

Chemistry and Pharmacology

Geosciences

Computer Science

Medicine

Natural Sciences in General

Physics

Botany, Ecology, Online Only

2018-08-18

American Association for the Advancement of Science (AAAS)

2375-2548

Natural Sciences in General

1399-3054

Blackwell Publishing Journal Backfiles 1879-2005

Biology

Dry weight of 34-day-old embryos from barley (Hordeum vulgare L.) cv. Bomi and high lysine mutants 527, 1508 and the double mutant 527/1508 were 1.00, 1.13, 1.56 and 2.22 mg, respectively. Embryos of the four lines were compared by light and electron microscopy and two dimensional gel electrophoresis. Morphological differences were restricted to the scutellar tissue, which had an irregular form in 1508 and the double mutant. Average scutellar cell volumes in 34-day-old embryos from cv. Bomi, mutants 527, 1508, and 527/1508 were 4 200, 8 300, 4 900 and 23 400 μm3. respectively. The starch content of the scutellar parenchyma cells was slightly higher in mutant 527 than in cv. Bomi, and considerably higher in mutant 1508 and the double mutant. The two dimensional gel electrophoretic examination showed that seven of the embryo protein spots were of a significantly different size in the mutants relative to those from cv. Bomi. Among these seven proteins, one was apparent only in the double mutant, four were more abundant in the mutants than in cv. Bomi and two were less abundant. The isoelectric points and the molecular weights of these proteins do not correspond exactly to those of proteins previously described in barley seeds.

Electronic Resource

0027-5107

Elsevier Journal Backfiles on ScienceDirect 1907 - 2002

Biology

Medicine

Electronic Resource

1399-3054

Blackwell Publishing Journal Backfiles 1879-2005

Biology

The dry grain weight of the Risø barley (Hordeum vulgare L. var. disticum) high lysine mutants 1508 and 527 at maturity was 32 and 37% lower, respectively, than the grains of the cultivar Bomi. Dry grain weight of the double mutant 527/1508 was reduced by 57%. Total number of endosperm nuclei from cv. Bomi, mutants 1508, 527 and 527/1508 at 24 days after anthesis was 173 000,156 000,121 000 and 111 000, respectively. Transverse mid-grain sections from mutants 1508 and 527 contained fewer aleurone cells and approximately the same number of starchy endosperm cells as cv. Bomi. The cellular organization of the endosperm of the double mutant deviated substantially from the normal. Cell volume in the central starchy endosperm of cv. Bomi, mutants 1508 and 527 at 33 days after anthesis averaged 390 000, 270 000 and 180 000 um5, respectively. Cell volume in the double mutant was smaller than in 527, but could not be accurately estimated due to the irregular shape of the cells. The mean section area of individual large starch granules in the central endosperm of mutants 1508, 527 and 527/1508 at 33 days after anthesis was 30, 48 and 72% smaller, respectively, than those of cv. Bomi. The average aleurone cell volume in cv. Bomi at 33 days after anthesis was 6 200 μm3.

Electronic Resource

1476-4687

Nature Archives 1869 - 2009

Biology

Chemistry and Pharmacology

Medicine

Natural Sciences in General

Physics

[Auszug] Potato wart has been known in Newfoundland since 1909 and is now found in all cultivated areas of the Island. It is distinctive in that it attacks a considerable number of varieties8, such as 'Arran Victory', 'Kerr's Pink', 'Ackersegen', and 'Libertas', which are immune from wart Bio type 1 in ...

Electronic Resource

1432-2048

Endosperm development ; Gene transcription (endosperm) ; Hordeum (sex mutant) ; Mutant(barley)

Springer Online Journal Archives 1860-2000

Biology

Abstract The rate of gene transcription in endosperm nuclei up to the formation of the first cell layers was investigated by pulse-labelling young fertilized barley (Hordeum vulgare L.) ovules with [3H]uridine. Quantitative autoradiographic studies of silver grains accumulating over the nuclei of wild-type endosperm demonstrated that the rate of transcription increased sixfold in the period from 3 to 7 d after pollination (DAP). Based on this observation, and the fact that cell-wall formation is initiated at 6 DAP, it is concluded that at least a proportion of the transcripts encode proteins involved in cell-wall formation. A similar study was also undertaken with the two barley sex mutants B7 and B15, in which developmental arrest at the syncytical stage leads to a complete lack of endosperm cell walls. This study showed that [3H]uridine is incorporated into the nuclei of the mutant syncytia, although at a rate different from that in the wild-type. Thus, the lack of cell-wall formation is not caused by a total block of gene transcription in these mutants, but rather by the lack of a gene product essential for cell-wall formation in the endosperm.

Electronic Resource

1432-2242

Barley ; Grain development ; Mutants ; Ultrastructure ; Genetics

Springer Online Journal Archives 1860-2000

Biology

Summary Eleven Na-azide induced barley shrunken endosperm mutants expressing xenia (sex) were characterized genetically and histologically. All mutants have reduced kernel size with kernel weights ranging from 11 to 57% of the wild type. With one exception, the mutant phenotypes are ascribable to single recessive mutant alleles, giving rise to a ratio of 3∶1 of normal and shrunken kernels on heterozygous plants. One mutant (B10), also monofactorially inherited, shows a gene dosage dependent pattern of expression in the endosperm. Among the 8 mutants tested for allelism, no allelic mutant genes were discovered. By means of translocation mapping, the mutant gene of B10 was localized to the short arm of chromosome 7, and that of B9 to the short arm of chromosome 1. Based on microscopy studies, the mutant kernel phenotypes fall into three classes, viz. mutants with both endosperm and embryo affected and with a non-viable embryo, mutants with both endosperm and embryo affected and with a viable embryo giving rise to plants with a clearly mutant phenotype, and finally mutants with only the endosperm affected and with a normal embryo giving rise to plants with normal phenotype. The mutant collection covers mutations in genes participating in all of the developmental phases of the endosperm, i.e. the passage from syncytial to the cellular endosperm, total lack of aleurone cell formation and disturbance in the pattern of aleurone cell formation. In the starchy endosperm, varying degrees of cell differentiation occur, ranging from slight deviations from wild type to complete loss of starchy endosperm traits. In the embryo, blocks in the major developmental phases are represented in the mutant collection, including arrest at the proembryo stage, continued cell divisions but no differentiation, and embryos deviating only slightly from the wild type.

Electronic Resource

1432-2242

ADP-glucose pyrophosphorylase ; Hor-deum vulgare ; RFLP-mapping ; Wheat/barley ditelosomic addition lines

Springer Online Journal Archives 1860-2000

Biology

Abstract cDNA probes encoding the barley endosperm ADP-glucose pyrophosphorylase (AGP) small subunit (bepsF2), large subunit (bepl10), and leaf AGP large subunit (blpl) were hybridized with barley genomic DNA blots to determine copy number and polymorphism. Probes showing polymorphism were mapped on a barley RFLP map. Probes that were not polymorphic were assigned to chromosome arms using wheat-barley telosomic addition lines. The data suggested the presence of a single-copy gene corresponding to each of the cDNA probes. In addition to the major bands, several weaker cross-hybridizing bands indicated the presence of other, related sequences. The weaker bands were specific to each probe and were not due to cross-hybridization with the other probes examined here. The endosperm AGP small subunit (bepsF2) majorband locus was associated with chromosome 1P and designated Aga1. The endosperm AGP large subunit (bepl10) major-band locus was mapped to chromosome 5M and designated Aga7. The endosperm AGP large-subunit minor bands were not mapped. The leaf AGP large-subunit major band was associated with chromosome 7M and designated Aga5. One of the leaf AGP large-subunit minor bands was mapped to chromosome 5P and designated Aga6. A clone for the wheat endosperm AGP large-subunit (pAga7) hybridized to the same barley genomic DNA bands as the corresponding barley probe indicating a high degree of identity between the two probes.

Electronic Resource

1615-6102

Cereals ; Endosperm ; Development ; Polarity ; Microtubules

Springer Online Journal Archives 1860-2000

Biology

Summary The endosperm of cereal grains develops as a multinucleate mass of wall-less cytoplasm (syncytium) that lines the periphery of the central cell before becoming cellular. The pattern of initial wall formation is precisely oriented and is followed by a round of precisely oriented formative cell division that gives rise to initials for the two tissues of endosperm. The initial anticlinal walls form at boundaries of nuclear-cytoplasmic domains (NCDs) defined by radial microtubules emanating from nuclei in the syncytium. Polarized growth of the NCDs in axes perpendicular to the embryo sac wall and centripetal elongation of the anticlinal walls results in a single layer of open ended alveoli overtopped by the remaining syncytial cytoplasm. This arboreal stage, so named because the elongate nucleate columns of cytoplasm resemble an orchard of trees, predicts the division polarity of the imminent formative division. Mitosis occurs as a wave which, like polarization, moves in both directions from ventral to dorsal. Spindles are oriented parallel to the long axis of the alveoli and cell plates give rise to periclinal walls. The outer daughter nuclei (aleurone initials) are thus completely enclosed by walls and the inner nuclei (starchy endosperm initials) are in alveoli adjacent to the central vacuole.

Electronic Resource

1573-5117

temperature logger ; muscle temperature ; Atlantic salmon ; slaughter procedures ; quality

Springer Online Journal Archives 1860-2000

Biology

Abstract This paper describes a micro controller based data logger designed to be externally attached to fish, in this case adult Atlantic salmon. The logger can measure ambient temperature and the temperature difference between ambient and dorsal white muscle, the latter with high resolution and accuracy. Communication with a computer for data transfer pass over a detachable transformer coupling. This transformer is also used to charge the internal battery. The logger can thus function without connectors, eliminating corrosion problems and simplifying encapsulation. Tracking of the muscle temperature is important for the development of better slaughter procedures. But the principles described in the following can also be useful for conventional tags and other kinds of underwater equipment.

Electronic Resource

0265-9247

Life and Medical Sciences ; Cell & Developmental Biology

Wiley InterScience Backfile Collection 1832-2000

Biology

Medicine

Endosperm is emerging as a system for investigating the genetic control of wall placement and deposition in plant development. Development of endosperm progresses in distinct stages from a wall-less syncytial stage to a cellular stage that is entirely typical of plant meristems where the division plane is predicted by a preprophase band of microtubules (PPB) and cytokinesis is completed by formation of a cell plate in association with a phragmoplast. Four developmentally different types of walls, each associated with a different microtubule system, are sequentially produced: (1) free growing walls deposited in the absence of mitosis and phragmoplasts; (2) walls guided by cytoplasmic phragmoplasts formed adventitiously in the absence of mitosis; (3) walls formed by interzonal phragmoplasts in a cell cycle that lacks PPBs; and (4) wall deposition driven by interzonal phragmoplasts in a cycle that includes PPBs. We are using methods of differential screening to isolate cDNA clones corresponding in temporal and spatial pattern to the types of wall development, and are studying mutants for clues to the genetic controls of wall development.

4 Ill.

Electronic Resource