Maintenance of mating reactivity and capacity of transferring meiotic induction by an activated to a homotypically united cell inBlepharisma
✍ Scribed by Santangelo, Giovanni ;Nobili, Renzo
- Publisher
- John Wiley and Sons
- Year
- 1981
- Tongue
- English
- Weight
- 504 KB
- Volume
- 218
- Category
- Article
- ISSN
- 0022-104X
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✦ Synopsis
Abstract
The two complementary mating types of Blepharisma japonicum, I and II, undergo cell pairing if activated by the complementary gamones. Pairs form in three possible combinations: I–I, II–II, I–II. In the two former unions (homotypic pairs), no nuclear changes occur in the cells. In the third union (heterotypic pairs), a diffusible factor produced during the first 2 hours of cell contact is assumed to induce meiosis and other nuclear changes in the cells. When cells were surgically separated during the first 2 hours after the onset of pairing, the behavior of cells from heterotypic pairs with respect to the occurrence of meiosis was alike in 93% of the cases. Cells of heterotypic pairs, separated from 0.66 to 2.66 hours after mixing complementary mating types, can homotypically reunite with gamone‐activated cells of their own mating type. The capacity of separated cells to reunite decreases as the time of heterotypic union increases. In 32 cases out of 80, separated cells whose partner underwent meiosis reunited, and three of them were able to induce macronuclear changes correlated to meiosis in the homotypically united cells.