Microtubule organization in sperm cells in the pollen tubes ofBrassica oleracea L.

PROTOPLASMA ◽  
1990 ◽  
Vol 154 (2-3) ◽  
pp. 151-156 ◽  
Author(s):  
M. Cresti ◽  
M. Murgia ◽  
C. H. Theunis
Keyword(s):  
Pollen Tubes ◽  
Sperm Cells ◽  
Microtubule Organization

scholarly journals Persistent directional growth capability in Arabidopsis thaliana pollen tubes after nuclear elimination from the apex

2021 ◽  
Vol 12 (1) ◽  
Author(s):  
Kazuki Motomura ◽  
Hidenori Takeuchi ◽  
Michitaka Notaguchi ◽  
Haruna Tsuchi ◽  
Atsushi Takeda ◽  
...  
Keyword(s):  
Arabidopsis Thaliana ◽  
Pollen Tube ◽  
Sperm Cell ◽  
Pollen Tubes ◽  
Vegetative Nucleus ◽  
Sperm Cells ◽  
Apical Region ◽  
Basal Region ◽  
Specific Expression ◽  
Directional Growth

AbstractDuring the double fertilization process, pollen tubes deliver two sperm cells to an ovule containing the female gametes. In the pollen tube, the vegetative nucleus and sperm cells move together to the apical region where the vegetative nucleus is thought to play a crucial role in controlling the direction and growth of the pollen tube. Here, we report the generation of pollen tubes in Arabidopsis thaliana whose vegetative nucleus and sperm cells are isolated and sealed by callose plugs in the basal region due to apical transport defects induced by mutations in the WPP domain-interacting tail-anchored proteins (WITs) and sperm cell-specific expression of a dominant mutant of the CALLOSE SYNTHASE 3 protein. Through pollen-tube guidance assays, we show that the physiologically anuclear mutant pollen tubes maintain the ability to grow and enter ovules. Our findings provide insight into the sperm cell delivery mechanism and illustrate the independence of the tip-localized vegetative nucleus from directional growth control of the pollen tube.

Sperm cells of the pollen tubes of Brassica: Ultrastructure and isolation

1991 ◽  
Vol 4 (3) ◽  
Author(s):  
P.E. Taylor ◽  
J. Kenrick ◽  
C.K. Blomstedt ◽  
R.B. Knox
Keyword(s):  
Pollen Tubes ◽  
Sperm Cells

scholarly journals Isolation of living sperm cells and in vitro fusion of Torenia fournieri gametes

2006 ◽  
Vol 12 (4) ◽  
Author(s):  
P. Vági ◽  
K. Imre ◽  
Z. Kristóf
Keyword(s):  
Male Gametophyte ◽  
Embryo Sac ◽  
Pollen Tubes ◽  
Sperm Cells ◽  
Torenia Fournieri ◽  
Isolation Medium ◽  
Vitro Fertilization ◽  
Crucial Part

In contrast to most angiosperms, Torenia contains a naked embryo sac and therefore has been considered since many years as an exciting model plant to study the double fertilization process of flowering seed plants. It is thus not surprising that the isolation of protoplasts from the female gametophyte has been reported already 20 years ago by Mol, the isolation of megaspores and megagametophytes has been published by the authors of this manuscript in 1996 and in 1999. The isolation of the male gametophyte and of sperm cells was published by the authors in 2004. The isolation of viable Torenia sperm cells is a crucial part of the elaboration of an in vitro fertilization system. Torenia sperm cells were isolated from in vivo — in vitro cultured pollen tubes. In this system pollen tubes first grow inside a cut style then follow their elongation in a solid isolation medium. The medium contained agarose in order to detain pollen tube contents. Released sperm cells and enzymatically isolated egg cells were collected and handled using glass micropipettes and transmitted to an electrofusion apparatus or polyethylene glycol containing media for fusion probes.

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.

Isolation of viable sperm cells from tobacco (Nicotiana tabacum)

Zygote ◽  
1996 ◽  
Vol 4 (2) ◽  
pp. 81-84 ◽  
Author(s):  
Yajuan Cao ◽  
Adonis Reece ◽  
Scott D. Russell
Keyword(s):  
Nicotiana Tabacum ◽  
Pollen Tubes ◽  
Growth Chamber ◽  
Sperm Cells ◽  
Mannitol Solution ◽  
Viable Sperm

SummaryViable sperm cells of Nicotiana tabacum were isolated by the semi-vivo technique. After pollination, excised styles were floated, cut end immersed, in a solution of 15% sucrose with 0.01% boric and 0.03% Ca(NO3)2 at 27°C in a growth chamber until pollen tubes emerged. After sperm cells were formed (at least 8 h after pollination) tubes were immersed in a 9% mannitol solution. In this solution, sperm cells are nearly ellipsoidal and retain viability for over 6 h.

Ultrastructure of sperm cells and the male germ unit in pollen tubes ofNicotiana tabacum

PROTOPLASMA ◽  
1989 ◽  
Vol 152 (1) ◽  
pp. 29-36 ◽  
Author(s):  
Hong-Shi Yu ◽  
Shi-Yi Hu ◽  
Cheng Zhu
Keyword(s):  
Pollen Tubes ◽  
Sperm Cells ◽  
Male Germ Unit ◽  
Ofnicotiana Tabacum

scholarly journals A Tug-of-War Model Explains the Saltatory Sperm Cell Movement in Arabidopsis thaliana Pollen Tubes by Kinesins With Calponin Homology Domain

2021 ◽  
Vol 11 ◽  
Author(s):  
Saskia Schattner ◽  
Jan Schattner ◽  
Fabian Munder ◽  
Eva Höppe ◽  
Wilhelm J. Walter
Keyword(s):  
Arabidopsis Thaliana ◽  
Pollen Tube ◽  
Sperm Cell ◽  
Cell Movement ◽  
Pollen Tubes ◽  
Vegetative Nucleus ◽  
Sperm Cells ◽  
Calponin Homology Domain ◽  
Calponin Homology ◽  
Actin Cables

Upon pollination, two sperm cells are transported inside the growing pollen tube toward the apex. One sperm cell fertilizes the egg cell to form the zygote, while the other fuses with the two polar nuclei to form the triploid endosperm. In Arabidopsis thaliana, the transport of the two sperm cells is characterized by sequential forward and backward movements with intermediate pauses. Until now, it is under debate which components of the plant cytoskeleton govern this mechanism. The sperm cells are interconnected and linked to the vegetative nucleus via a cytoplasmic projection, thus forming the male germ unit. This led to the common hypothesis that the vegetative nucleus is actively transported via myosin motors along actin cables while pulling along the sperm cells as passive cargo. In this study, however, we show that upon occasional germ unit disassembly, the sperm cells are transported independently and still follow the same bidirectional movement pattern. Moreover, we found that the net movement of sperm cells results from a combination of both longer and faster runs toward the pollen tube apex. We propose that the observed saltatory movement can be explained by the function of kinesins with calponin homology domain (KCH). This subgroup of the kinesin-14 family actively links actin filaments and microtubules. Based on KCH's specific properties derived from in vitro experiments, we built a tug-of-war model that could reproduce the characteristic sperm cell movement in pollen tubes.

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