Dynamic analyses of the expression of the HISTONE::YFP fusion protein in arabidopsis show that syncytial endosperm is divided in mitotic domains.
During early seed development, nuclear divisions in the endosperm are not followed by cell division, leading to the development of a syncytium. The simple organization of the Arabidopsis endosperm provides a model in which to study the regulation of the cell cycle in relation to development. To monitor nuclear divisions, we constructed a HISTONE 2B::YELLOW FLUORESCENT PROTEIN gene fusion (H2B::YFP). To validate its use as a vital marker for chromatin in plants, H2B::YFP was expressed constitutively in Arabidopsis. This enabled the observation of mitoses in living root meristems. H2B::YFP was expressed specifically in Arabidopsis syncytial endosperm by using GAL4 transactivation. Monitoring mitotic activity in living syncytial endosperm showed that the syncytium was organized into three domains in which nuclei divide simultaneously with a specific time course. Each mitotic domain has a distinct spatiotemporal pattern of mitotic CYCLIN B1;1 accumulation. The polar spatial organization of the three mitotic domains suggests interactions between developmental mechanisms and the regulation of the cell cycle.
Unité Mixte de Recherche 5667, Centre National de la Recherche Scientifique, Institut National de la Recherche Agronomique, Ecole Nationale Supérieure de Lyon, Université Lyon I, 46 Allée d'Italie, 69364 Lyon Cedex 07, France.
C
C
Boisnard-Lorig
A
A
Colon-Carmona
M
M
Bauch
S
S
Hodge
P
P
Doerner
E
E
Bancharel
C
C
Dumas
J
J
Haseloff
F
F
Berger
D017360:Arabidopsis / Q000166:cytology / Q000196:embryology* / Q000235:genetics / Q000378:metabolism; D019677:Artificial Gene Fusion; D001426:Bacterial Proteins / Q000235:genetics*; D002454:Cell Differentiation; D002455:Cell Division; D002467:Cell Nucleus / Q000235:genetics; D002843:Chromatin / Q000378:metabolism; D016213:Cyclins / Q000235:genetics; D004268:DNA-Binding Proteins; D005656:Fungal Proteins; D020440:Gene Duplication; D005819:Genetic Markers; D015726:Giant Cells / Q000166:cytology* / Q000378:metabolism; D006657:Histones / Q000235:genetics*; D008164:Luminescent Proteins / Q000235:genetics*; D018613:Microscopy, Confocal; D008938:Mitosis; D011123:Polyploidy; D011993:Recombinant Fusion Proteins / Q000235:genetics / Q000378:metabolism*; D029701:Saccharomyces cerevisiae Proteins; D012639:Seeds / Q000166:cytology / Q000235:genetics / Q000648:ultrastructure; D014157:Transcription Factors
D001426:Bacterial Proteins; D002843:Chromatin; D016213:Cyclins; D004268:DNA-Binding Proteins; D005656:Fungal Proteins; C052130:GAL4 protein, S cerevisiae; D005819:Genetic Markers; D006657:Histones; D008164:Luminescent Proteins; D011993:Recombinant Fusion Proteins; D029701:Saccharomyces cerevisiae Proteins; D014157:Transcription Factors; C054562:yellow fluorescent protein, Bacteria