| 1. |
- Hilson, P., et al.
(författare)
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Versatile gene-specific sequence tags for Arabidopsis functional genomics : Trancript profiling and reverse genetics applications
- 2004
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Ingår i: Genome Research. - : Cold Spring Harbor Laboratory. - 1088-9051 .- 1549-5469. ; 14:10B, s. 2176-2189
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Tidskriftsartikel (refereegranskat)abstract
- Microarray transcript profiling and RNA interference are two new technologies crucial for large-scale gene function studies in multicellular eukaryotes. Both rely on sequence-specific hybridization between complementary nucleic acid strands, inciting us to create a collection of gene-specific sequence tags (GSTs) representing at least 21,500 Arabidopsis genes and which are compatible with both approaches. The GSTs were carefully selected to ensure that each of them shared no significant similarity with any other region in the Arabidopsis genome. They were synthesized by PCR amplification from genomic DNA. Spotted microarrays fabricated from the GSTs show good dynamic range, specificity, and sensitivity in transcript profiling experiments. The GSTs have also been transferred to bacterial plasmid vectors via recombinational cloning protocols. These cloned GSTs constitute the ideal starting point for a variety of functional approaches, including reverse genetics. We have subcloned GSTs on a large scale into vectors designed for gene silencing in plant cells. We show that in planta expression of GST hairpin RNA results in the expected phenotypes in silenced Arabidopsis lines. These versatile GST resources provide novel and powerful tools for functional genomics.
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| 2. |
- Cowling, R. J., et al.
(författare)
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The role of PASTICCINO1, an FKBP-like protein, in plant development
- 1999
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Bok (övrigt vetenskapligt/konstnärligt)abstract
- The pasticcino (pas) mutants of Arabidopsis thaliana were identified due to their abnormal response to cytokinins. These mutants fall into 3 complementation groups: pas1 (2 alleles), pas2 (1 allele) and pas3 (4 alleles). The mutants all have excessive and disorganised cell divisions leading to extra cell layers in the hypocotyl, abnormal apical meristems, and rosettes with fused vitreous leaves. This cell proliferation effect is exaggerated in the presence of cytokinins. The PAS1 gene was cloned via a T-DNA insertion; it encodes for a protein with similarities to FK506-binding proteins (FKBPs), a class of immunophilins. Like other large FKBPs the PAS1 protein has several putative FKBP domains, a tetratricopeptide repeat domain and a calmodulin binding motif. PAS1 also has conserved nuclear localisation signals. Although the presence of immunophilins has been demonstrated in plants, their functions are unknown. PAS1 is the first plant immunophilin-like gene to be disrupted and suggests a role for PAS 1 in the control of plant cell division.
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| 3. |
- Creusot, F., et al.
(författare)
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The CIC YAC library: Sizing of the clones and determination of clones carrying repeated DNA sequences.
- 1995
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Ingår i: The Plant Journal. - 0960-7412 .- 1365-313X. ; 8:5, s. 763-770
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Tidskriftsartikel (refereegranskat)abstract
- A new Arabidopsis thaliana (ecotype Columbia) genomic library has been constructed in Yeast Artificial Chromosomes: the CIC library (for CEPH, INRA and CNRS). Optimization of plant culture conditions and protoplast preparation allowed the recovery of large amounts of viable protoplasts. Mechanical shearing of DNA was minimized by isolation of DNA from protoplasts embedded in agarose. Cloning of large inserts was favored by including two successive size fractionation steps (after partial EcoRI digestion and after ligation with the vector arms), which selected DNA fragments larger than 350 kb. The library consists of 1152 clones with an average insert size of 420 kb. Clones carrying chloroplast DNA and various nuclear repeated sequences have been identified. Twenty-one per cent of the clones are found to contain chloroplast DNA. Therefore, the library represents around four nuclear genome equivalents. The clones containing 5S rDNA genes, 18S-25S rDNA sequences and the 180 bp paracentromeric repeated element account for 3.6%, 8.9% and 5.8%, respectively. Only one clone was found to carry the 160 bp paracentromeric repeated element. Given the smaller size of clones carrying Arabidopsis repeated DNA, the average size of remaining clones is around 480 kb. The library was screened by PCR amplification using pairs of primers corresponding to sequences dispersed in the genome. Seventy out of 76 pairs of primers identified from one to seven YAC clones. Thus at least 92% of the genome is represented in the CIC library. The survey of the library for clones containing unlinked DNA sequences indicates that the proportion of chimeric clones is lower than 10%.
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| 4. |
- Desnos, T., et al.
(författare)
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Procuste1 mutants identify two distinct genetic pathways controlling hypocotyl cell elongation, respectively in dark and light-grown Arabidopsis seedlings
- 1996
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Ingår i: Development. - 0950-1991 .- 1477-9129. ; 122:2, s. 683-693
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Tidskriftsartikel (refereegranskat)abstract
- Plant morphogenesis is dependent on a tight control of cell division and expansion. Cell elongation during postembryonic hypocotyl growth is under the control of a light-regulated developmental switch. Light is generally believed to exert its effects on hypocotyl elongation through a phytochrome- and blue-light receptor- mediated inhibitory action on a so far unknown cell elongation mechanism. We describe here a new class of allelic mutants in Arabidopsis, at the locus PROCUSTE1 (prc1-1 to -4), which have a hypocotyl elongation defect specifically associated with the dark-grown developmental program. Normal hypocotyl elongation is restored in plants grown in white, blue or red light. In agreement with this, the constitutive photomorphogenic mutation cop1-6, which induces a deetiolated phenotype in the dark, is epistatic to prc1-2 for the hypocotyl phenotype. Epistasis analyses in red and blue light respectively, indicate that phytochrome B but not the blue light receptor HY4, is required for the switch from PRC1-dependent to PRC1-independent elongation. The conditional hypocotyl growth defect is associated with a deformation of the hypocotyl surface due to an uncontrolled swelling of epidermal, cortical or endodermal cells, suggesting a defect in the structure of the expanding cell wall, A similar phenotype was observed in elongating roots, which was however, independent of the light conditions. The aerial part of mature mutant plants grown in the light was indistinguishable from the wild type. prc1 mutants provide a means of distinguishing, for the first time, two genetic pathways regulating hypocotyl cell elongation respectively in dark- and light-grown seedlings, whereby light not only inhibits hypocotyl growth, but also activates a PRC1-independent cell elongation program.
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| 5. |
- Traas, J., et al.
(författare)
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Normal Differentiation Pattern in Plants Lacking Microtubular Preprophase Bands
- 1995
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Ingår i: Nature. - : Springer Science and Business Media LLC. - 0028-0836 .- 1476-4687. ; 375:6533, s. 676-677
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Tidskriftsartikel (refereegranskat)abstract
- IT is generally accepted that polarized cell expansion and the strict control of division plane alignment are prerequisites for ordered spatial development in higher plants(1). This appears to be linked to the presence of cell walls, which immobilize the cells and fix their relative positions. In this context, the cortical cytoskeleton is thought to play a central role(1-6). Interphase microtubules are often aligned perpendicular to the growth axis and it has been proposed that they control cell expansion, probably in combination with the cell wall. Another cytoskeletal array, the prephophase band, has been associated with division plane alignment. This structure, which girdles the cell at the G2 phase of the cell cycle and at prophase, precisely predicts the future division site and probably fixes it. Here we describe different mutants in Arabidopsis that are unable to form these two cortical microtubular arrays. As expected, this defect is associated with irregular cell expansion and the inability to align division planes. Surprisingly, however, the mutations do not affect differentiation patterns: all cell types and organs are in their correct relative positions.
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| 6. |
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| 7. |
- Faure, J. D., et al.
(författare)
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The PASTICCINO genes of Arabidopsis thaliana are involved in the control of cell division and differentiation
- 1998
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Ingår i: Development. - 0950-1991 .- 1477-9129. ; 125:5, s. 909-918
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Tidskriftsartikel (refereegranskat)abstract
- The control of cell division by growth regulators is critical to proper plant development. The isolation of single-gene mutants altered in the response to plant hormones should permit the identification of essential genes controlling the growth and development of plants. We have isolated mutants pasticcino belonging to 3 complementation groups (pas1, pas2, pas3) in the progeny of independent ethyl methane sulfonate and T-DNA mutagenized Arabidopsis thaliana plants. The screen was performed in the presence or absence of cytokinin. The mutants isolated were those that showed a significant hypertrophy of their apical parts when grown on cytokinin-containing medium. The pas mutants have altered embryo, leaf and root development. They display uncoordinated cell divisions which are enhanced by cytokinin. Physiological and biochemical analyses show that cytokinins are probably involved in pas phenotypes. The PAS genes have been mapped respectively to chromosomes 3, 5 and 1 and represent new plant genes involved in the control of cell division and plant development.
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