Fine structure of sperm cells in pollen grains ofBeta

PROTOPLASMA ◽  
1969 ◽  
Vol 68 (1-2) ◽  
pp. 237-240 ◽  
Author(s):  
Lynn L. Hoefert
Keyword(s):  
Fine Structure ◽  
Pollen Grains ◽  
Sperm Cells

Isolation and Characterization of Viable Sperm Cells from Tricellular Pollen Grains

1988 ◽  
pp. 245-250 ◽  
Author(s):  
E. Matthys-Rochon ◽  
S. Detchepare ◽  
V. Wagner ◽  
P. Roeckel ◽  
C. Dumas
Keyword(s):  
Pollen Grains ◽  
Sperm Cells ◽  
Isolation And Characterization ◽  
Viable Sperm

Development of sperm cells in barley

1975 ◽  
Vol 53 (10) ◽  
pp. 1051-1062 ◽  
Author(s):  
David D. Cass ◽  
Ilana Karas
Keyword(s):  
Cell Membrane ◽  
Vegetative Cell ◽  
Generative Cell ◽  
Pollen Grains ◽  
Complete Separation ◽  
Pollen Wall ◽  
Vegetative Nucleus ◽  
Sperm Cells ◽  
Subsequent Stage ◽  
Microspore Stage

Ultrastructural events in barley sperm development were examined from the uninucleate microspore stage to establishment of two mature sperm cells in pollen grains. Microspore mitosis produces a vegetative nucleus and a naked generative cell, both embedded in vegetative cell cytoplasm. The generative cell membrane is enclosed by vegetative cell membrane. The generative cell, at first apparently unattached, becomes attached to the pollen wall and acquires a cell wall by centripetal vesicle accumulation. Wall formation may be complete at the time of generative cell karyokinesis; karyokinesis occurs while the generative cell is attached to the pollen wall. Cytokinesis of the generative cell is delayed. The subsequent stage is a binucleate, attached generative cell with a wall. Generative cell cytokinesis appears to involve formation of a partition between the two sperm nuclei. Eventual complete separation of the sperm cells occurs only after the two-celled derivative of the generative cell detaches from the pollen wall. Final stages in sperm cell separation are considered to result from degradation of the partitioning and surrounding wall, not from furrowing of a naked binucleate generative cell according to previous suggestions. Mature plastids were not observed in the generative cell or the sperms.

scholarly journals KAKU4-mediated deformation of the vegetative nucleus controls its precedent migration over sperm cells in pollen tubes

2019 ◽  
Author(s):  
Chieko Goto ◽  
Kentaro Tamura ◽  
Satsuki Nishimaki ◽  
Naoki Yanagisawa ◽  
Kumi Matsuura-Tokita ◽  
...  
Keyword(s):  
Competitive Ability ◽  
Pollen Grains ◽  
Nuclear Lamina ◽  
Pollen Tubes ◽  
Vegetative Nucleus ◽  
Sperm Cells ◽  
Wild Type ◽  
Cell Nuclei ◽  
In The Wild ◽  
Dense Accumulation

AbstractA putative nuclear lamina protein, KAKU4, modulates nuclear morphology in Arabidopsis thaliana seedlings but its physiological significance is unknown. KAKU4 was strongly expressed in mature pollen grains, each of which has a vegetative cell and two sperm cells. KAKU4 protein was highly abundant on the envelopes of vegetative nuclei (VNs) and less abundant on the envelopes of sperm cell nuclei (SCNs) in pollen grains and elongating pollen tubes. VN is irregularly shaped in wild-type pollen. However, KAKU4 deficiency caused it to become more spherical. These results suggest that the dense accumulation of KAKU4 is responsible for the irregular shape of the VNs. After a pollen grain germinates, the VN and SCNs migrate to the tip of the pollen tube. In the wild type, the VN preceded the SCNs in 91–93% of the pollen tubes, whereas in kaku4 mutants, the VN trailed the SCNs in 39–58% of the pollen tubes. kaku4 pollen was less competitive than wild-type pollen after pollination, although it had an ability to fertilize. Taken together, our results suggest that controlling the nuclear shape in vegetative cells of pollen grains by KAKU4 ensures the orderly migration of the VN and sperm cells in pollen tubes.HighlightThe nuclear envelope protein KAKU4 is involved in controlling the migration order of vegetative nuclei and sperm cells in pollen tubes, affecting the competitive ability of pollen for fertilization.

EDX microanalysis of cellular components in the pollen of an angiosperm, Plumbago zeylanica

1990 ◽  
Vol 48 (3) ◽  
pp. 804-805
Author(s):  
S. D. Russell
Keyword(s):  
Pollen Grains ◽  
Sperm Cells ◽  
Limited Information ◽  
Plumbago Zeylanica ◽  
X Ray ◽  
Distribution Of Elements ◽  
Specific Proteins ◽  
Quantum Detector ◽  
Cellular Components ◽  
Edx Microanalysis

Pollen grains in flowering plants recognize compatible stigmas and transmit the sperm cells that they contain to the egg. The pollen grains bear specific proteins and lipids on their outer walls, which are the principal sources of both pollen-stigma recognition and human allergic response; they also contain the organelles required to form the pollen tube and the two sperm cells that participate in double fertilization. Although limited information is available about x-ray microanalysis of pollen grains, no information is available about the cellular distribution of elements.The contents of pollen of Plumbago zeylanica L. were burst in double-distilled water onto formvar-coated Cu slot grids ( 1 × 2 mm) and air-dried at room temperature. Grids were then examined at 40 kV in a JEOL 2000 STEM (LaB6 e' source) equipped with a high-angle 10 mm2 Kevex Quantum detector and Delta analyzer. Spectra were collected for 100-500 livetime sec; digital x-ray maps were collected at resolutions of up to 128 × 256 (dwell time: 30 msec [10-15 collections], 15-30% deadtime at ca. 1,000 cps, adjusted using the free lens control).

scholarly journals A High Density of rRNA in the Generative Cells and Sperm Cells of Pollen Grains of Five Angiosperm Species.

CYTOLOGIA ◽  
1998 ◽  
Vol 63 (3) ◽  
pp. 293-300 ◽  
Author(s):  
Chieko Saito ◽  
Makoto Fujie ◽  
Atsushi Sakai ◽  
Noriko Nagata ◽  
Sachihiro Matsunaga ◽  
...  
Keyword(s):  
Pollen Grains ◽  
High Density ◽  
Sperm Cells ◽  
Angiosperm Species ◽  
Generative Cells

Fine structure of Rossipollis reticulatus from the Upper Cretaceous of southern Sweden

2004 ◽  
Vol 82 (7) ◽  
pp. 927-937 ◽  
Author(s):  
Annie Skarby ◽  
Marta A Morbelli ◽  
John R Rowley
Keyword(s):  
Fine Structure ◽  
Upper Cretaceous ◽  
Pollen Grains ◽  
Fossil Pollen ◽  
Fluvial Sediments ◽  
Southern Sweden ◽  
Innermost Layer ◽  
Pollen Sacs

Dispersed monosulcate pollen identified as Rossipollis reticulatus Ross and similar pollen in two pollen sacs from a single anther were recovered from Upper Cretaceous fluvial sediments in southern Sweden. In most pollen grains the wall consists of a foot layer, an inner solid reticulum, crowned by columellae, which appear as an infratectal reticulum, and a tectum with irregularly spaced fine perforations. An additional papillate innermost layer, interpreted as a transitory endexin, is present in some pollen grains. A monocotyledonous origin is indicated by the configuration of exine and aperture along with the presence of papillate endexine structures in grains considered to have aborted at earlier stages of development.Key words: Cretaceous, fossil pollen, endexine, monocots.

scholarly journals Fine structure of the male genital systems, spermatophores and unusual sperm cells of Saxidromidae (Acari, Actinotrichida)

Acarologia ◽  
2010 ◽  
Vol 50 (2) ◽  
pp. 243-256 ◽  
Author(s):  
G. Alberti ◽  
Y. Coineau ◽  
N.A. Fernandez ◽  
P.D. Theron
Keyword(s):  
Fine Structure ◽  
Sperm Cells ◽  
Male Genital
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