摘要:

SummaryIn this report, the isolation ofParamecium tetraureliamutants resistant to the polyene antibiotics amphotericin B and filipin are described. These antibiotics are known to specifically interact with membrane sterols to produce a cytotoxic effect. Four mutants resistant to amphotericin B and two mutants resistant to filipin have been isolated. In each case, an individual mutant shows resistance to both amphotericin B and filipin. Genetic analysis indicates that all 6 mutations map to the same complementation group and are not allelic to any of the 3 pawn mutations or to either of the two“barium shy”mutations. The behavioral analysis suggests that these mutations cause an alteration of normal ion channel function. Direct electrophysiological analysis of one mutant indicates mutations to polyene antibiotic resistance cause a specific decrease in voltage-sensitive Ca2+channel activity.

ISSN:0167-7063    

DOI:10.3109/01677068609106896

出版商:Taylor&Francis    

年代:1986

数据来源: Taylor

摘要:

SummaryIn stationary flightDrosophila melanogasterproduces yaw torque in response to visual movement stimuli. The residual optomotor yaw torque response of the mutantoptomotor-blindH31(omb), which lacks the horizontal (HS) and vertical (VS) giant fibers in the lobula plate, differs from that of wild-type in several aspects: it is restricted to the frontal visual field, it is only elicited by front-to-back motion and appears to be mediated by a different set of elementary movement detectors (EMDs). Using a single black stripe as motion stimulus the torque response is, even in wild-type flies, dominated by the frontal visual field and by front-to-back motion. We thus propose thatDrosophila'soptomotor yaw control is organized as two partially parallel subunits. The component still displayed byombis called“object response”; the component missing in the mutant (which is presumably mediated by the giant HS-cells in the wild-type) is called“large field response”Several properties of the object response are described.

ISSN:0167-7063    

DOI:10.3109/01677068609106897

出版商:Taylor&Francis    

年代:1986

数据来源: Taylor

摘要:

SummaryTo test the hypothesis that associative learning is the basis for conditioned courtship, maleDrosophila melanogasterwere paired with virgin females in the presence of quinine, known to be a negative reinforcer in a learning paradigm independent of courtship. Such“experienced”wild-type males failed to court virgin females and remained refractory to them for 1-2 h. But experienced males from the learning-defective strain,dunce, continued to court females at high levels; and experienced males from the retention-defective strain,amnesiac, failed to demonstrate the wild-type refractory period. Finally, males from thedon giovannistrain, defective with respect to fertilized-female conditioning, were conditioned by presentation of virgin females and quinine. Courtship-depressing effects of cis-vaccenyl alcohol, which can be recovered from fertilized females, were confirmed, but no evidence for its role as a negative reinforcer of male courtship was obtained.

ISSN:0167-7063    

DOI:10.3109/01677068609106898

出版商:Taylor&Francis    

年代:1986

数据来源: Taylor

摘要:

SummaryTwo brothers aged 75 and 61 years, born from non-consanguineous non-affected parents, had spinocerebellar ataxia and impaired proprioception in the lower limbs, associated with sensorineural deafness, amyotrophy of the hands and spastic paraparesis. The older patient also had vitiligo of the right hand, and both displayed likely dysendocrine features. The disease was present since the second-third decade and showed a slow course. An EMG confirmed a neurogenic disorder strictly localized to the distal upper limbs. This new phenotype of heredoataxia is compared with previously reported similar syndromes and, in particular, with diseases featuring localized amyotrophy of the hands.

ISSN:0167-7063    

DOI:10.3109/01677068609106899

出版商:Taylor&Francis    

年代:1986

数据来源: Taylor