Survival at 20� C and cryopreservation of isolated sperm cells from Zea mays pollen grains

Roeckel, P.; Dumas, Christian

doi:10.1007/bf00228651

Cited by 12 publications

(6 citation statements)

References 14 publications

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“…Using solutions containing 4.27 mM calcium, Roeckel and Dumas (1993) found spontaneous sperm cell fusions that formed large, initially multinucleated cells in isolated maize gametes. Using solutions containing 4.27 mM calcium, Roeckel and Dumas (1993) found spontaneous sperm cell fusions that formed large, initially multinucleated cells in isolated maize gametes.…”

Section: Calcium and Fusion Of Gametesmentioning

confidence: 99%

Calcium function and distribution during fertilization in angiosperms

Tian²,

Russell³

2007

American J of Botany

111

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Calcium has an essential signaling, physiological, and regulatory role during sexual reproduction in flowering plants; elevation of calcium amounts is an accurate predictor of plant fertility. Calcium is present in three forms: (1) covalently bound calcium, (2) loosely bound calcium typically associated with fixed and mobile anions (ionic bonding); and (3) cytosolic free calcium-an important secondary messenger in cell signaling. Pollen often requires calcium for germination. Pollen tube elongation typically relies on external calcium stores in the pistil. Calcium establishes polarity of the pollen tube and forms a basis for pulsatory growth. Applying calcium on the tip may alter the axis; thus calcium may have a role in determining the directionality of tube elongation. In the ovary and ovule, an abundance of calcium signals receptivity, provides essential mineral nutrition, and guides the pollen tube in some plants. Calcium patterns in the embryo sac also correspond to synergid receptivity, reflecting programmed cell death in one synergid cell that triggers degeneration and prepares this cell to receive the pollen tube. Male gametes are released in the synergid, and fusion of the gametes requires calcium, according to in vitro fertilization studies. Fusion of plant gametes in vitro triggers calcium oscillations evident in both the zygote and primary endosperm during double fertilization that are similar to those in animals.

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Section: Calcium and Fusion Of Gametesmentioning

confidence: 99%

Calcium function and distribution during fertilization in angiosperms

Tian²,

Russell³

2007

American J of Botany

111

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“…At 1×10 5 cells/ml, the frequency of bicellular fusion was 26%; at 1×10 6 cells/ml, this decreased to 18%, with many fusions involving more than two cells. Large multinucleated fusion products were also reported in experiments using maize sperm cells in calcium-containing media (Roeckel and Dumas 1993). Recently, Zhang et al (1997) reported calcium-induced fusion of maize sperm cells, and also found that the rates of fusion increased with increasing concentrations of calcium.…”

Section: Requirements For Sperm Cell Fusionmentioning

confidence: 81%

“…Apparently, once inhibitors to fusion have been removed, the fusion of two sperm cells in tight contact is possible. Roeckel and Dumas (1993) and Zhang et al (1997) report that calcium is a critical element in the fusion of sperm cells of maize. Although sperm cells of tobacco could be fused in enzymatic solutions without calcium, calcium increased fusion efficiency and decreased the time required for the fusion process from 5 min to 20 s. Our results indicate that the sperm cells of tobacco are strongly fusigenic under these conditions, but that spontaneous fusion is normally prevented in vivo.…”

Section: Requirements For Sperm Cell Fusionmentioning

confidence: 99%

The fusion of sperm cells and the function of male germ unit (MGU) of tobacco ( Nicotiana tabacum L.)

Tian

Russell

1998

Sexual Plant Reproduction

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“…Our microscopic observations have revealed that these large cells are multinucleate (unpublished data), suggesting the occurrence of sperm fusion. Roeckel and Dumas (1993) also reported aggregates of multinucleate maize sperms in the presence of BKS and 3 mM (total 4.27 mM) calcium. However, detailed information regarding the formation and nature of such multinucleate cells is not available.…”

Section: Introductionmentioning

confidence: 91%

Calcium-induced sperm fusion in Zea mays L.

Zhang

Liu

Cass

1997

Sexual Plant Reproduction

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In this study, we examined morphological changes of isolated maize (Zea mays L.) sperm cells in the presence of Brewbaker and Kwack salts (BKS) or the individual components of BKS using light, transmission electron and scanning electron microscopy. Freshly isolated sperms are 7.5 µm in diameter. Treatment with BKS for 5 h resulted in large cells with a diameter up to 41 µm. Staining of sperm nuclei with 4′, 6-diamidino-2-phenylindole (DAPI) revealed two or more nuclei in a single cell, suggesting that BKS induces cell fusion. Treatment with each BKS component showed that cell fusion occurs only in the presence of calcium nitrate. Use of several calcium salts showed the same results, suggesting that the calcium ion, alone, is responsible for the observed cell fusion. Further studies were conducted to examine the relationship between calcium distribution and sperm location in pollen tubes using chlorotetracycline and DAPI. Growing maize pollen tubes exhibited a high membrane calcium region within 20-50 µm from the tip. The Sperms are found no closer than 90 µm to the tip of the tube, suggesting that sperms are located in a low calcium region prior to being released to the degenerating synergid.

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Survival at 20� C and cryopreservation of isolated sperm cells from Zea mays pollen grains

Cited by 12 publications

References 14 publications

Calcium function and distribution during fertilization in angiosperms

Calcium function and distribution during fertilization in angiosperms

The fusion of sperm cells and the function of male germ unit (MGU) of tobacco ( Nicotiana tabacum L.)

Calcium-induced sperm fusion in Zea mays L.

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