Laurie G Smith

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We have discovered that all known yeast and vertebrate small nucleolar RNAs (snoRNAs), except for the MRP/7-2 RNA, fall into two major classes. One class is defined by conserved boxes C and D and the other by a novel element: a consensus ACA triplet positioned 3 nt before the 3' end of the RNA. A role for the ACA box is snoRNA stability has been established(More)
Dominant mutations of the Knotted-1 (Kn1) homeobox gene of maize alter the differentiation and growth of cells associated with leaf veins. By analyzing Kn1 transcripts and KN1 protein, we show that the gene is not expressed at high levels during the development of wild-type leaves. Instead, Kn1 is expressed in apical meristems of vegetative and floral(More)
The product of the maize homeobox gene, knotted1 (kn1), localizes to the nuclei of cells in shoot meristems, but is absent from portions of the meristem where leaf primordia or floral organs initiate. Recessive mutant alleles of kn1 were obtained by screening for loss of the dominant leaf phenotype in maize. Mutant kn1 alleles carrying nonsense, splicing(More)
The human DNA mismatch repair gene homologue hMSH2, on chromosome 2p is involved in hereditary non-polyposis colon cancer (HNPCC). On the basis of linkage data, a second HNPCC locus was assigned to chromosome 3p21-23 (ref. 3). Here we report that a human gene encoding a protein, hMLH1 (human MutL homologue), homologous to the bacterial DNA mismatch repair(More)
Polarization of cell division is essential for eukaryotic development, but little is known about how this is accomplished in plants. The formation of stomatal complexes in maize involves the polarization of asymmetric subsidiary mother cell (SMC) divisions toward the adjacent guard mother cell (GMC), apparently under the influence of a GMC-derived signal.(More)
The cytoskeleton plays important roles in plant cell shape determination by influencing the patterns in which cell wall materials are deposited. Cortical microtubules are thought to orient the direction of cell expansion primarily via their influence on the deposition of cellulose into the wall, although the precise nature of the microtubule-cellulose(More)
BACKGROUND In premitotic plant cells, the future division plane is predicted by a cortical ring of microtubules and F-actin called the preprophase band (PPB). The PPB persists throughout prophase, but is disassembled upon nuclear-envelope breakdown as the mitotic spindle forms. Following nuclear division, a cytokinetic phragmoplast forms between the(More)
Spatial control of cytokinesis in plant cells depends on guidance of the cytokinetic apparatus, the phragmoplast, to a cortical "division site" established before mitosis. Previously, we showed that the Tangled1 (Tan1) gene of maize is required for this process during maize leaf development (Cleary, A.L., and L.G. Smith. 1998. Plant Cell. 10:1875-1888.).(More)
Plant cell shapes are defined by their surrounding walls, but microtubules and F-actin both play critical roles in cell morphogenesis by guiding the deposition of wall materials in expanding cells. Leaf epidermal cells have lobed shapes, which are thought to arise through a microtubule-dependent pattern of locally polarized growth. We have isolated a(More)
The shapes of plant cells, which are defined by their surrounding walls, are often important for cell function. The cytoskeleton plays key roles in determining plant cell shape, mainly by influencing the patterns in which wall materials are deposited in expanding cells. Studies employing cytoskeleton-disrupting drugs, together with studies of mutants with(More)