摘要:

Theshibirets2mutation ofDrosophila melanogastercauses a temperature sensitive inhibition of endocytosis; this in turn leads to synaptic-vesicle depletion and consequent paralysis. Heat-pulses delivered during development ofshibirets2individuals affect the morphology of a number of adult structures. A simple screening protocol has been used to isolate several mutations that partially suppress the temperature-sensitive paralytic phenotype ofshibirets2mutant animals. All of these mutations very tightly linked toshibireand are likely to be second site intragenic mutations that restore partial activity to theshibirets2product. The mutations suppress both behavioral, and easily-scored developmental phenotypes ofshibirets2characterized in this paper. Our results suggest that defects in endocytosis, and not in microtubule interactions, are responsible for all of the phenotypes ofshibirets2mutantDrosophilaexamined in this study.

ISSN:0167-7063    

DOI:10.3109/01677069309083451

出版商:Taylor&Francis    

年代:1993

数据来源: Taylor

摘要:

The pathologic phenotype of the testis in both prepuberal and postpuberal maleweavermutant mice was studied by light microscopy. Morphometric analysis of seminiferous tubules was carried out. Epididymal fluid was examined for the presence of spermatozoa. The seminiferous tubules of 21-day-old prepuberalweavermutant mice lacked patent lumina and had more degenerated cells than control mice. Fifty-six day-oldweavermutants had many germinal epithelial cells located within the adluminal compartment that were in advanced stages of degeneration. Round spermatids were enlarged and multinucleated. Round spermatids and spermatocytes had sloughed into the lumen. Compared to control mice, elongated spermatids were seen less frequently. In olderweavermice, the degenerative process involved germ cells in both the adluminal and basal compartments. In 143- and 226- day-oldweavermutants, the Sertoli cells were atrophic. Diameters of seminiferous tubules inweavermice were significantly reduced when compared to control mice. Sperm were either absent or very low in number in the epididymal fluid of postpuberalweavermice. We conclude that spermatogenesis is abnormal in maleweavermutant mice. The testicular phenotype is characterized by a degenerative process that affects both germ cells and supporting cells.

ISSN:0167-7063    

DOI:10.3109/01677069309083452

出版商:Taylor&Francis    

年代:1993

数据来源: Taylor

摘要:

no-bridgeKS49(nob) has been shown to have a disturbed protocerebral bridge (pb). Using monoclonal antibodies that stain selectively some central complex regions we found that the protocerebral pridge defect is accompanied by a loss of certain inputs and outputs of the central complex. Mutantnobflies have a reduced climbing activity due to a reduced average walking speed and to a spastic state. Their mean longevity is drastically reduced, suggesting thatnobis a pleiotropic gene. Thenobmutant is impaired in habituation and in Pavlovian conditioning of the proboscis extension reflex (PER), although its initial reactivity to the sucrose stimulus is normal. Tested in habituation of the PER by ipsi- and contralateral stimulations, thenobmutant shows some difficulties in the“data exchange”between the two brain hemispheres, suggesting that the central complex may coordinate information processing in the two hemispheres.

ISSN:0167-7063    

DOI:10.3109/01677069309083453

出版商:Taylor&Francis    

年代:1993

数据来源: Taylor

摘要:

Thescalloped (sd)locus ofDrosophila melanogasterencodes a protein with a novel DNA binding domain bearing a high degree of similarity to the human transcription factor TEF-1 (Campbell et al., 1992). We demonstrate thatsdmutants show defects in response to a number of taste stimuli. Higher stimulus concentrations are required to elicit behavioral responses from mutant larvae and adult flies. The electrophysiological responses of the peripheral taste neurons in the labellum were found to be normal, suggesting that an inability to detect stimuli is not the cause of the mutant phenotype. The range of mutant responses ofsdalleles to salt and sugar stimuli define a functional requirement for the gene in the nervous system and provide an assay for the genetic and molecular analysis of this role.

ISSN:0167-7063    

DOI:10.3109/01677069309083454

出版商:Taylor&Francis    

年代:1993

数据来源: Taylor