摘要:

We investigated the neuromuscular transmission in relation with genetic neuronal excitability changes in mutantsT(X;Y)V7andShKS133ofDrosophila.These mutations affect two different genes belonging to theShakergene complex which encode different yet functionally related proteins. Experiments were performed on neuromuscular junctions fromDrosophilalarvae by recording pre- and postsynatic membrane currents using external electrodes. It was found that the neuromuscular electrophysiological phenotype ofT(X;Y)V7is caused by presynaptic membrane hyperexcitability probably in relation with a Ca2+-dependent down regulation of voltage dependent K channels. By contrast, theShKS133phenotype can be explained solely by action potential widening due to the absence of type-A K channels.

ISSN:0167-7063    

DOI:10.3109/01677069109066212

出版商:Taylor&Francis    

年代:1991

数据来源: Taylor

摘要:

Drosophila ebonymutants exhibit a syndrome of morphological and behavioral phenotypes that include an abnormally dark body color and defects in visual and courtship responses. We now show that mutants carrying any one of fiveebonyalleles display complex and variable locomotor activity rhythms. Although in the most extreme cases activity is essentially aperiodic, many individuals express short- and/or long-period activity components. Three differentebonymutants (e, e1, ande11) express free-running rhythmicity in a temperature-dependent manner; activity rhythms are robust at 28°C. but weak or absent at 20°C. Even while maintained in a light-dark (LD) cycle,ebonyhomozygotes characteristically display extremely disorganized patterns of activity: some individuals entrain with an apparently abnormal phase and/or express multiple rhythmic components. Interestingly, the visual system mutationnorpApartially suppresses effects of thee1allele, which suggests that aberrant visual system inputs might contribute to the rhythm deficits ofebonymutants. In contrast to their effects on the locomotor activity rhythm,ebonymutations have no apparent impact on the circadian rhythm of adult eclosion, and thus exert rhythm-specific effects on circadian periodicity.

ISSN:0167-7063    

DOI:10.3109/01677069109066213

出版商:Taylor&Francis    

年代:1991

数据来源: Taylor

摘要:

A new clock mutant, namedAndante, has been identified on the X chromosome ofDrosophila melanogaster. Andantelengthens the period of the circadian eclosion and locomotor activity rhythms by 1.5–2.0 hours. The phase response curves for the eclosion and activity rhythms, indicating light-induced phase shifts, show a similar degree of lengthening.Andantealso lengthens the periods of other clock mutants, includingClock, and alleles of theperiodlocus. Analysis of locomotor activity rhythms reveals thatAndanteis semi-dominant, andAndanterhythms are highly temperature compensated. Thesine oculismutation, which eliminates the outer visual system, has no effect on the period ofAndante.Deficiency mapping indicates thatAndanteis located in the IOEI-2 to IOFI region of the X chromosome, close to theminiature-duskylocus. WhereasAndanteflies have aduskywing phenotype,duskyflies do not have anAndanteclock phenotype.

ISSN:0167-7063    

DOI:10.3109/01677069109066214

出版商:Taylor&Francis    

年代:1991

数据来源: Taylor

ISSN:0167-7063    

DOI:10.3109/01677069109066215

出版商:Taylor&Francis    

年代:1991

数据来源: Taylor