title: Interactions between janus and bcd cortical pattern mutants in Tetrahymena thermophila : An investigation of intracellular patterning mechanisms using double-mutant analysis.
abstract: An analysis of bcd, janA; bcd, janB; and bcd, janC double-mutant phenotypes in Tetrahymena thermophila has allowed us to examine patterning processes affected by two different classes of mutations. bcd brings about a broadening of the oral and contractile vacuole pore domains in the ciliate cortex, while the janus mutations generate a mirror-image duplication of the ventral cortical pattern. We observed both bcd and janus characteristics expressed in the double mutants, as well as features unique to the double-mutant. Temperature-shift experiments employing the temperature-sensitive janB mutation in a double-mutant (bcd, janB) combination allowed us to observe the changes in pattern as a mirror-image geometry was brought into expression and subsequently removed within the bcd, janB double homozygote. These experiments suggest that there are multiple pattern-mechanisms at work with differing kinetics of expression in the ciliate cortex. We discuss how the bcd mutation could influance expression of the janus mutations in light of a model previously proposed to account for the janus phenotype.
authors.affiliation: Biology Department, University of Iowa, 52242, Iowa City, Ia., USA.
authors.forename: Eric Stephen
authors.initials: ES
authors.lastname: Cole
authors.affiliation: Biology Department, University of Iowa, 52242, Iowa City, Ia., USA.
authors.forename: Joseph
authors.initials: J
authors.lastname: Frankel
authors.affiliation: Biology Department, University of Iowa, 52242, Iowa City, Ia., USA.
authors.forename: Leslie Meek
authors.initials: LM
authors.lastname: Jenkins
keywords: Cell surface patterns; Ciliate development; Double mutant analysis; Tetrahymena thermophila