A Mutational Analysis of Conjugation inTetrahymena thermophila

摘要: Abstract Conjugation following pair formation in Tetrahymena can be divided into three distinct sequences of events: prezygotic development, postzygotic and exconjugant development. The decision to proceed with development is governed by a developmental checkpoint occurring sometime during the middle stages conjugation. A second made initiate separation This paper examines phenotypes five newly isolated conjugation mutants ( cnj6–cnj10 ) which affect late events within program. cnj6 exhibit normal nuclear behavior throughout up including differentiation new macronuclear anlagen. Pairs arrest at this endpoint, unable dissociate. cnj7 cnj8 eliminate third division first division. All subsequent appear normal. cnj9 eliminates division, subsequently, macronuclei fail develop despite parental degradation. cnj10 results pleiotropic phenotype characterized failure numerous all involve nuclear–cytoskeletal interactions. These defects include selection (anchoring nuclei exchange junction), pronuclear exchange, fusion, anchoring products posterior cell cortex. mutant are used draw inferences regarding dependencies that govern cell's entry programs.