ISSN:
1615-6102
Keywords:
Cytokinesis
;
Cytoplasmic domains
;
Meiosis
;
Microtubules
;
Minispindles
Source:
Springer Online Journal Archives 1860-2000
Topics:
Biology
Notes:
Summary Changes in the microtubular cytoskeleton during meiosis and cytokinesis in hybrid moth orchids were studied by indirect immunofluorescence. Lagging chromosomes not incorporated into telophase nuclei after first meiotic division behave as small extra nuclei. Events in the microtubular cycle associated with these micronuclei are similar to and synchronous with those of the principal nuclei. During second meiotic division the micronuclei trigger formation of minispindles which are variously oriented with respect to the two principal spindles. After meiosis, radial systems of microtubules measure cytoplasmic domains around each nucleus in the coenocyte. Cleavage planes are established in regions where opposing radial arrays interact and the cytoplasm cleaved around micronuclei is proportionately smaller than that around the four principal nuclei. These observations clearly demonstrate that nuclei in plant cells are of fundamental importance in microtubule organization and provide strong evidence in support of our recently advanced hypothesis that division planes in simultaneous cytokinesis following meiosis are determined by establishment of cytoplasmic domains via radial systems of nuclear-based microtubules rather than by division sites established before nuclear division.
Type of Medium:
Electronic Resource
URL:
http://dx.doi.org/10.1007/BF01403988
