| Gene Information | |
| NCBI Gene ID | 830326 |
| Symbol | SIM |
| LocusTag | AT5G04470 |
| Synonyms | SIAMESE|T19N18.8 |
| Description | SIM (SIAMESE) |
| Gene Type | protein-coding |
| Pattern | SIM|AT5G04470|SIAMESE|T19N18.8|SIM (SIAMESE) |
| Corresponding sequence in Trichome EST library | |
| Reference |
|
Genetic interaction between glabra3-shapeshifter and siamese in Arabidopsis thaliana converts trichome precursors into cells with meristematic activity. Marks MD, Gilding E, Wenger JP. Plant J. 2007 Oct;52(2):352-61. ...... ability to form a complex with the GL1 protein (a MYB transcription factor required for trichome formation), leading to changes in gene expression compared with wild type during gl3-sst mutant trichome development. The other mutant allele, sim, is a likely loss of function allele derived from the SIM locus, which is predicted to encode a negative regulator of D-type cyclin activity. The gl3-sst sim double mutant exhibits mounds of cells derived from the proliferation of single ...... |
|
Novel plant-specific cyclin-dependent kinase inhibitors induced by biotic and abiotic stresses. Peres A, Churchman ML, Hariharan S, Himanen K, Verkest A, Vandepoele K, Magyar Z, Hatzfeld Y, Van Der Schueren E, Beemster GT, Frankard V, Larkin JC, Inze D, De Veylder L. J Biol Chem. 2007 Aug 31;282(35):25588-96. ...... of Orysa; CYCD5;3 to complement a budding yeast (Saccharomyces cerevisiae) triple CLN mutant, whereas recombinant protein inhibited CDK activity in vitro. Moreover, Orysa;EL2 was able to rescue the multicellular trichome phenotype of sim mutants of Arabidopsis, unequivocally demonstrating that Orysa;EL2 operates as a cell cycle inhibitor. Orysa;EL2 mRNA levels were induced by cold, drought, and propionic acid. Our data suggest that Orysa;EL2 encodes a new type of plant CDK ...... |
|
SIAMESE, a plant-specific cell cycle regulator, controls endoreplication onset in Arabidopsis thaliana. Churchman ML, Brown ML, Kato N, Kirik V, Hülskamp M, Inzé D, De Veylder L,Walker JD, Zheng Z, Oppenheimer DG, Gwin T, Churchman J, Larkin JC. Plant Cell. 2006 Nov;18(11):3145-57. ...... Recessive mutations in the SIAMESE (SIM) gene of Arabidopsis thaliana result in multicellular trichomes harboring individual nuclei with a low ploidy level, a phenotype strikingly different from that of wild-type trichomes, which are single cells with a nuclear DNA content ...... |
|
Trichome morphogenesis: a cell-cycle perspective. Schnittger A, Hulskamp M. Philos Trans R Soc Lond B Biol Sci. 2002 Jun 29;357(1422):823-6. Review. ...... of branch formation: (i) a role of the microtubule cytoskeleton; and (ii) a link to the regulation of cell divisions. The latter aspect is supported by the recent identification of an Arabidopsis mutant with multicellular trichomes, the siamese mutant, suggesting that Arabidopsis trichomes are evolutionarily derived from multicellular forms. We speculate that the spatial information for branch formation is derived from mechanisms employed in cell divisions. ...... |
|
Ectopic B-type cyclin expression induces mitotic cycles in endoreduplicating Arabidopsis trichomes. Schnittger A, Schobinger U, Stierhof YD, Hulskamp M. Curr Biol. 2002 Mar 5;12(5):415-20. ...... CYCLIN B1;1, induces mitotic divisions resulting in multicellular trichomes. The CYCLIN B1;2-triggered cell divisions appeared normal with respect to both nuclear division and cytokinesis. We show that CYCLIN B1;2 is misexpressed in the siamese mutant, which also produces multicellular trichomes. Additional overexpression of CYCLIN B1;2 in a siamese mutant background caused a strongly enhanced phenotype. ...... |
|
SIAMESE, a gene controlling the endoreduplication cell cycle in Arabidopsis thaliana trichomes. Walker JD, Oppenheimer DG, Concienne J, Larkin JC. Development. 2000 Sep;127(18):3931-40. ...... typically resulting in a nondividing cell with a unique differentiated morphology. The unicellular trichomes of Arabidopsis are a well-established model for the study of plant cell differentiation. Here, we describe a new genetic locus, SIAMESE (SIM), required for coordinating cell division and cell differentiation during the development of Arabidopsis trichomes (epidermal hairs). A recessive mutation in the sim locus on chromosome 5 results in clusters of adjacent trichomes that ...... |
|
...... mutant was found to produce multicellular trichomes in contrast to the unicellular trichomes produced by wild-type (WT) plants. Mutant trichomes consisting of up to 15 cells have been observed. Scanning electron microscopy of developing sim trichomes suggests that the cell divisions occur very early in the development of mutant trichomes. WT trichome nuclei continue to replicate their DNA after mitosis and cytokinesis have ceased, and as a consequence have a DNA content much ...... |
|
...... than 2C. This phenomenon is known as endoreduplication. Individual nuclei of sim trichomes have a reduced level of endoreduplication relative to WT trichome nuclei. Endoreduplication is also reduced in dark-grown sim hypocotyls relative to WT, but not in light-grown hypocotyls. Double mutants of sim with either of two other mutants affecting endoreduplication, triptychon (try) and glabra3 (gl3) are consistent with a function for SIM in ...... |