Summary
Isolated egg cell protoplasts ofZea mays L., inbred line A 188, have been studied at the transmission electron microscope level. Their preparation for electron microscopy has been performed by embedding in ultra-low gelling agarose as a preliminary step. Five isolated egg cell protoplasts were serially ultrathin sectioned and studied in detail. One of these protoplasts was reconstructed in three dimensions to provide additional information on its structure. After enzymatic digestion and microdissection, isolated egg cells are true, highly vacuolized protoplasts. The structure of their organelles agrees with in situ observations, indicating an ultrastructural intactness after isolation: the mitochondria are polymorphic, form reticulate networks, and have well developed cristae; the plastids contain starch grains; and the spherical nucleus is euchromatic. As in situ, the organelles of the isolated egg cell protoplasts are aggregated near the nucleus. The complete picture provided by this work should serve as a comparative base for studies on in vitro fertilization products.
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References
Cass DD (1973) An ultrastructural and Nomarski-interference study of the sperms of barley. Can J Bot 51: 601–605
—, Fabi GC (1988) Structure and properties of sperm cells isolated from the pollen ofZea mays. Can J Bot 66: 819–825
Chaboud A, Perez R (1992) Generative cells and male gametes: isolation, physiology and biochemistry. In: Russell SD, Dumas C (eds) Sexual reproduction in flowering plants. Int Rev Cytol 140: 205–232
Diboll AG (1968) Fine structural development of the megagametophyte ofZea mays following fertilization. Amer J Bot 55: 787–806
—, Larson DA (1966) An electron microscopic study of the mature megagametophyte inZea mays. Amer J Bot 53: 391–402
Dow DA, Mascarenhas JP (1991) Optimization of conditions for in situ hybridization and determination of the relative number of ribosomes in the cells of the mature embryo sac of maize. Sex Plant Reprod 4: 244–249
Dupuis I, Dumas C (1990) Biochemical markers of female receptivity in maize (Zea mays L.) assessed using in vitro fertilization. Plant Sci 70: 11–19
—, Roeckel P, Matthys-Rochon E, Dumas C (1987) Procedure to isolate viable sperm cells from corn (Zea mays L.) pollen grains. Plant Physiol 85: 876–878
Huang B-Q, Russell SD (1989) Isolation of fixed and viable eggs, central cells and embryo sacs from ovules ofPlumbago zeylanica. Plant Physiol 90: 9–12
—, Russell SD, Strout GW, Mao L-J (1990) Organization of isolated embryo sacs and eggs ofPlumbago zeylanica (Plumbaginaceae) before and after fertilization. Amer J Bot 77: 1401–1410
—, Pierson ES, Russell SD, Tiezzi A, Cresti M (1992) Video microscopic observations of living, isolated embryo sacs ofNicotiana and their component cells. Sex Plant Reprod 5: 156–162
Jensen WA (1965) The ultrastructure and composition of the egg and central cell of cotton. Amer J Bot 52: 781–797
Koop HU, Schweiger HG (1985) Regeneration of plants from individually cultivated protoplasts using an improved microculture system. J Plant Physiol 121: 245–257
Kranz E, Bautor J, Lörz H (1990) In vitro fertilization of single, isolated gametes, transmission of cytoplasmic organelles and cell reconstitution of maize (Zea mays L.). In: Nijkamp HJJ, Van der Plas LHW, Van Aartrijk J (eds) Progress in plant cellular and molecular biology. Proceedings of the VIIth International Congress on Plant Tissue and Cell Culture, Amsterdam, The Netherlands, 24–29 June 1990. Kluwer, Dordrecht, pp 252–257
— — — (1991) In vitro fertilization of single, isolated gametes of maize by electrofusion. Sex Plant Reprod 4: 12–16
Matthys-Rochon E, Vergne P, Detchepare S, Dumas C (1987) Male germ unit isolation from three tricellular pollen species:Brassica okracea, Zea mays, andTriticum aestivum. Plant Physiol 83: 464–466
—, Detchepare S, Wagner V, Roeckel P, Dumas C (1988) Isolation and characterization of viable sperm cells from tricellular pollen grains. In: Cresti M, Gori P, Pacini E (eds) Sexual reproduction in higher plants. Springer, Berlin Heidelberg New York Tokyo, pp 245–250
McConchie CA, Hough T, Knox RB (1987) Ultrastructural analysis of the sperm cells of mature pollen of maize,Zea mays. Protoplasma 139: 9–19
Mogensen HL, Suthar HK (1979) Ultrastructure of the egg apparatus ofNicotiana tabacum (Solanaceae) before and after fertilization. Bot Gaz 140: 168–179
—, Wagner VT, Dumas C (1990) Quantitative three-dimensional ultrastructure of isolated corn (Zea mays) sperm cells. Protoplasma 153: 136–140
Perez R, Chaboud A, Dumas C (1992) Molecular study of acquisition of receptivity inZea mays silks. In: Molecular control of flower development and plant reproduction. International Workshop, Amsterdam, The Netherlands, 12–16 April 1992, p 44
Rusche ML, Mogensen HL (1988) The male germ unit ofZea mays: quantitative ultrastructure and three-dimensional analysis. In: Cresti M, Gori P, Pacini E (eds) Sexual reproduction in higher plants. Springer, Berlin Heidelberg New York Tokyo, pp 221–226
Russell SD (1991) Isolation and characterization of sperm cells in flowering plants. Annu Rev Plant Physiol 42: 189–204
Schulz R, Jensen WA (1968)Capsella embryogenesis: the egg, zygote, and young embryo. Amer J Bot 55: 807–819
Spurr AR (1969) A new viscosity resin embedding medium for electron microscopy. J Ultrastruct Res 26: 31–43
Theunis CH, Pierson ES, Cresti M (1991) Isolation of male and female gametes in higher plants. Sex Plant Reprod 4: 145–154
Van Lammeren AAM (1986) A comparative ultrastructural study of the megagametophytes in two strains ofZea mays L. before and after fertilization. Agric Univ Wageningen Papers 86: 1–37
Wagner VT, Song YC, Matthys-Rochon E, Dumas C (1988) The isolated embryo sac ofZea mays: structural and ultrastructural observations. In: Cresti M, Gori P, Pacini E (eds) Sexual reproduction in higher plants. Springer, Berlin Heidelberg New York Tokyo, pp 125–130
—, Dumas C, Mogensen HL (1989 a) Morphometric analysis of isolatedZea mays sperm. J Cell Sci 93: 179–184
—, Song YC, Matthys-Rochon E, Dumas C (1989 b) Observations on the isolated embryo sac ofZea mays L. Plant Sci 59: 127–130
—, Dumas C, Mogensen HL (1990) Quantitative three-dimensional study on the position of the female gametophyte and its constituent cells as a prerequisite for corn (Zea mays) transformation. Theor Appl Genet 79: 72–76
Young SJ, Royer SM, Goves PM, Kinnamon JC (1987) Three-dimensional reconstructions from serial micrographs using the IBM PC. J Electron Microsc Tech 6: 207–218
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Faure, J.E., Mogensen, H.L., Kranz, E. et al. Ultrastructural characterization and three-dimensional reconstruction of isolated maize (Zea mays L.) egg cell protoplasts. Protoplasma 171, 97–103 (1992). https://doi.org/10.1007/BF01403723
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DOI: https://doi.org/10.1007/BF01403723