Four-dimensional imaging and computer-assisted track analysis of nuclear migration in root hairs of Arabidopsis thaliana.
Nuclear migration is a fundamental mechanism necessary for the proper growth and development of many eukaryotic organisms. In this study root hairs of Arabidopsis thaliana were used as a research model to gain insight into the dynamics of nuclear migration. Root hairs are long tubular outgrowths of epidermal cells and are responsible for the uptake of water and nutrients. During the development of root hairs, the nucleus migrates into the hair after the bulge is formed. The position of the nucleus relative to the tip plays an essential role in the growth process. However, what is happening to the nucleus in full-grown root hairs is still unclear. To study nuclear dynamics in living root hair cells, stably transformed plants with the fusion proteins Histone2B-YFP and NLS-GFP-GUS were used. Four-dimensional confocal laser scanning microscopy made it possible to monitor the exact position of the nucleus in different root hairs. To analyse the sequential positions of the nuclei in the root hairs, a new computer-assisted method was developed. After track analysis a number of parameters could be extracted from the movies, such as the average speed, the amplitude, direction factor and the range of movement in the root hairs. Our results show that nuclei do not reach a final position in full-grown root hairs and this sustained movement seems to be more similar in root hairs lying close to each other. Moreover, with this methodology it could be quantitatively demonstrated that the integrity of actin is necessary for nuclear movement.
Van Bruaene
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Laboratory for Biochemistry and Molecular Cytology, Ghent University, Coupure Links 653, 9000 Gent, Belgium. nathalie.vanbruaene@rug.ac.be
Joss
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G
Thas
O
O
Van Oostveldt
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P
D017360:Arabidopsis / Q000235:genetics / Q000378:metabolism / Q000648:ultrastructure*; D029681:Arabidopsis Proteins / Q000235:genetics / Q000378:metabolism*; D001426:Bacterial Proteins / Q000235:genetics / Q000378:metabolism; D002467:Cell Nucleus / Q000502:physiology*; D018506:Gene Expression Regulation, Plant; D005966:Glucuronidase / Q000235:genetics / Q000378:metabolism; D049452:Green Fluorescent Proteins; D006657:Histones / Q000235:genetics / Q000378:metabolism; D007091:Image Processing, Computer-Assisted; D008164:Luminescent Proteins / Q000235:genetics / Q000378:metabolism; D018613:Microscopy, Confocal / Q000295:instrumentation; D019913:Nuclear Localization Signals / Q000235:genetics / Q000378:metabolism; D018517:Plant Roots / Q000254:growth & development*; D011993:Recombinant Fusion Proteins / Q000235:genetics / Q000378:metabolism
D029681:Arabidopsis Proteins; D001426:Bacterial Proteins; D006657:Histones; D008164:Luminescent Proteins; D019913:Nuclear Localization Signals; D011993:Recombinant Fusion Proteins; C054562:yellow fluorescent protein, Bacteria; D049452:Green Fluorescent Proteins; D005966:Glucuronidase