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11.
N. V. Shamina Zh. M. Mukhina N. M. Kovaleva V. A. Filiurina 《Cell and Tissue Biology》2011,5(2):186-195
The paper presents previously undescribed abnormalities of phragmoplast formation in pollen mother cells of grass haploids
and allohaploids (wide hybrids of the first generation). These abnormal phenotypes reveal and illustrate occasional unknown
stages of phragmoplast formation in dividing plant cells and indicate the special regulation of their initiation, as well
as confirm data on this process obtained by other approaches. 相似文献
12.
By means of morphological analyses of meiotic abnormalities in pollen mother cells (PMCs) of cereal wide hybrids, haploids and meiotic mutants, the processes involved in cytoskeleton cycle at late prometaphase (a sub-stage of transition from chaotic figure to bipolar spindle) were studied. A significance of the four processes of late prometaphase--axial orientation, lateral association, consolidation and convergance of spindle fibers--is discussed. 相似文献
13.
Morphogenesis and functioning of polyarchal spindles in higher plant meiosis were studied. A mechanism of anastral spindle formation in discussed. 相似文献
14.
Rearrangements of microtubular cytoskeleton during telophase in pollen mother cells of some dicotyledon plants with the simultaneous cytokinesis during normal and abnormal meiosis were studied. At telophase I, a potentially functional phragmoplast forms between daughter nuclei, but no cell plate is present. During interkinesis, the phragmoplast plays the role of an interphase cytoskeleton array. Dynamics of microtubule reorganization in polar regions of the telophase spindle is discussed in addition to the role played by microtubule convergence centers in cytoskeleton rearrangements during meiosis. 相似文献
15.
An overview of a set of our previous papers titled "Dynamics of microtubular cytoskeleton in higher plant meiosis" is presented, in addition to some data on subcellular mechanisms underlying cytoskeleton reorganization during meiotic division in pollen mother cells. An illustrated scheme of cytoskeleton rearrangements during plant meiosis, both with successive and simultaneous cytokinesis, is given. 相似文献
16.
The inability of phragmoplast to stop its centrifugal movement after reaching the mother cell membrane is described in abnormal meiosis with the arrest of cell plate formation. The excess of phragmoplast expansion leads to rotation of the whole telophase figure (phragmoplast with daughter nuclei) within the cell through 90 degrees. It has been suggested that this phenomenon may occur because of a the lack of signal stopping cytokinesis. Such a signal arises due to formation of daughter cell membranes. 相似文献
17.
18.
N. V. Shamina L. F. Dudka V. Ya. Kovtunenko E. U. Bolobolova 《Cell and Tissue Biology》2009,3(2):168-172
The compensation for phragmoplast dysfunction in the male meiosis of F1 wheat × rye hybrids was described. In pollen mother cells (PMCs), he transition from central spindle fibers (forming a solid bundle) to phragmoplast (hollow cylinder) was blocked. This blockage suppresses the centrifugal movement of the phragmoplast and cell-plate formation. As a result, cells become binucleate. Sometimes, two nuclei fuse and form one restitution nucleus. In PMCs of the wheat × rye F1 hybrid D-144 gp 06 year (T. aestivum n. 93-60 t 9 × S. cereale n. Saratovskaya 7) with this phenotype, an additional phragmoplast is formed at the late telophase. This occurs by a common mechanism for the development of the immobile phragmoplast in the meiosis in bicotyledons; new phragmoplasts arise as a result of microtubule polymerization starting from the spindle poles. The accessory phragmoplast facilitates a new cell plate assembly and achievement of cytokinesis. 相似文献
19.
Monopolar spindles in pollen mother cells of cereal wide F1 hybrids are described; details of the formation of anastral spindles are discussed. 相似文献
20.
Fourteen Indian populations ofD. melanogaster collected along a 22° latitudinal range were analyzed electrophoretically to compare the geographical patterns of allozymic variation at 13 loci. The data show higher genetic differentiation on the basis of moderate to higherF
ST values and significant statistical correlation of allelic frequencies at six polymorphic loci with latitude. The results add support to the hypothesis that the occurrence of parallel or complementary latitudinal clines across different continental populations provides evidence of natural selection maintaining such clinal variation. 相似文献