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Evidence for the discontinuity of plastids in the sexual reproduction of a plant


, : Evidence for the discontinuity of plastids in the sexual reproduction of a plant. Journal of Ultrastructure Research 15(1): 108-121

Investigation of the fine structure of the egg cell of Pteridium aquilinum, a fern, reveals that the mature egg contains only large amoeboid proplastids, strikingly different from the plastids of the central cell. Early in the life of the egg there is a phase in which numerous vesicular bodies, less than 1 u in diameter and identified as degenerate plastids, are present in the cytoplasm. As the egg matures these bodies gradually disappear, and simultaneously the nucleus of the egg throws out conspicuous evaginations. Many of these, particularly toward the end of the maturation process, and for about 6 hours after fertilization, are saclike, the contents being in continuity with the nucleoplasm. Arguments are presented for believing that these saclike evaginations become detached, and form plastid initials. Their subsequent development is similar to that of the plastid initials of embryonic cells, and the proplastids so formed replace those eliminated early in the maturation of the egg. This interpretation is held to be compatible with the results of breeding experiments with variegated plants.

US$19.90

PMID: 5949180

DOI: 10.1016/s0022-5320(66)80098-9


Other references

Asahina S., 1973: Taxonomic notes on japanese blattaria part 5 on 3 recently introduced blattellid species. Medical Entomology & Zoology 24(2): 123-128

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Chen, Y.X.; Qu, P., 1980: Defective polymorphonuclear leucocyte (PMN) chemotaxis and serum inhibition in patients with malignant diseases. Zhonghua Zhong Liu Za Zhi 2(1): 19-23

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Jabusch, Henry W., 1961: Quality control in yeast raised doughnut production. Baker S Digest 35(2): 64-66

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Rance, M.; Boulat, B.; Cavanagh, J.; Krishnan, V.V., 1995: NMR studies of dynamical processes in proteins and nucleic acids. Journal of Biomolecular Structure & Dynamics 12(6): A196