Involvement of 14-nm Filament-Forming Protein and Tubulin in Gametic Pronuclear Behavior during Conjugation in Tetrahymena |
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Authors: | IBUKI TAKAGI OSAMU NUMATA YOSHIO WATANABE |
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Affiliation: | Institute of Biological Sciences, University of Tsukuba, Tsukuba 305, Japan |
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Abstract: | We have studied in detail the immunofluorescence localizations of Tetrahymena 14-nm filament-forming protein (49-kDa protein) in relation to tubulin in conjugating wild-type Tetrahymena thermophila (B strain) pairs and in pairs between B strain and star strains with defective micronuclei. The results suggest that germ nuclear behavior during conjugation may involve the following cytoskeletal structures: (1) during meiosis, microtubule structures are involved in micronuclear elongation and meiotic division; (2) at the postmeiotic stage, 49-kDa protein network structures that are formed independently of the existence of pronuclei are involved in the selection and the survival of one of four meiotic products; (3) during the third prezygotic division, gametic pronuclear transfer, and zygote formation, a cytoskeletal structure in which the 49-kDa protein colocalizes with microtubules and which is dependent on the existence of a normal gametic pronucleus is involved in gametic pronuclear behavior, and (4) during the postzygotic divisions, the microtubules are involved in nuclear behavior. |
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Keywords: | Fertilization meiosis microtubules Tetrahymena thermophila. |
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