This Article Full Text Full Text (PDF) Supplemental Data All Versions of this Article: 19/9/2793    most recent tpc.107.053231v1 Alert me when this article is cited Alert me if a correction is posted Services Email this article to a friend Similar articles in this journal Similar articles in ISI Web of Science Similar articles in PubMed Alert me to new issues of the journal Download to citation manager Citing Articles Citing Articles via CrossRef Citing Articles via Google Scholar Google Scholar Articles by Dittmer, T. A. Articles by Richards, E. J. Search for Related Content PubMed PubMed Citation Articles by Dittmer, T. A. Articles by Richards, E. J. Agricola Articles by Dittmer, T. A. Articles by Richards, E. J.

LITTLE NUCLEI Genes Affecting Nuclear Morphology in Arabidopsis thaliana^[W]

^a Department of Biology, Washington University, St. Louis, Missouri 63130
^b Department of Cell and Developmental Biology, John Innes Centre, Norwich NR4 7UH, United Kingdom

² Address correspondence to richards{at}wustl.edu.

Efforts to understand nuclear organization in plant cells have received little assistance from the better-studied animal nuclei, because plant proteomes do not contain recognizable counterparts to the key animal proteins involved in nuclear organization, such as lamin nuclear intermediate filament proteins. Previous studies identified a plant-specific insoluble nuclear protein in carrot (Daucus carota), called Nuclear Matrix Constituent Protein1 (NMCP1), which contains extensive coiled-coil domains and localizes to the nuclear periphery. Here, we describe a genetic characterization of two NMCP1-related nuclear proteins in Arabidopsis thaliana, LITTLE NUCLEI1 (LINC1) and LINC2. Disruption of either gene caused a reduction in nuclear size and altered nuclear morphology. Moreover, combining linc1 and linc2 mutations had an additive effect on nuclear size and morphology but a synergistic effect on chromocenter number (reduction) and whole-plant morphology (dwarfing). The reduction in nuclear size in the linc1 linc2 double mutant was not accompanied by a corresponding change in endopolyploidy. Rather, the density of DNA packaging at all endopolyploid levels in the linc1 linc2 mutants was increased significantly. Our results indicate that the LINC coiled-coil proteins are important determinants of plant nuclear structure.