Ref ID : 7495
Mark A. Virtue and Eric S. Cole; A Cytogenetic Study of Development in Mechanically Disrupted Pairs of Tetrahymena thermophila. J.Eukaryot.Microbiol. 46(6):597-605, 1999
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We examined the nuclear behavior of mating Tetrahymena cells that had been mechanically disrupted at various times throughout conjugation. Disruption was achieved by agitating conjugating Tetrahymena in the presence of 0.1-3 mm glass beads. Two minutes of agitation with 1 mm beads yielded optimal pair disruption (70%) with high viability (92%). Disrupting pairs between 0-4.7 hr after the initiation of mating produced mostly disrupted conjugants in which development was aborted. However, as many as 20% of these early disrupted conjugants completed development even without their mating partners. After 5 hr the precentage of disrupted conjugants completing development increased dramatically, reaching 80% by 6.7 hr. These results support a model suggesting that events associated with nuclear exchange and fusion 5 hr into conjugation trigger a commitment to completion of the postzygotic developmental program. The early conjugants that completed development following disruption suggest that development can be sustained even in the absence of a mating partner. This represents a novel method of bringing the micronuclear genome into macronuclear expression with minimal cytoplasmic exchange between partners. We discuss these results in light of a model relating cortical and nuclear signaling events that reciprocally drive conjugal development.