0000000000133399
AUTHOR
Heinz Sass
Interspecific transgenic analysis of basal versus heat-shock-induced expression of a Drosophila pseudoobscura hsp82-neo fusion gene in D. melanogaster
Drosophila melanogaster transformants containing a D. pseudoobscura hsp82-neo fusion gene were used to examine the relationship between chromosome structure and its variation to transcriptional activation and gene expression. At normal temperatures (25° C) transgenic hsp82-neo was transcribed in diffuse polytene chromosomal bands encoding antibiotic G418-resistance without intensive puff formation. Substantial basal expression of the transgene was observed in all tissues examined: salivary glands, brain, ventral ganglion, foregut, gastric caeca, midgut, imaginal discs, nurse cells and oocytes. In addition, basal hsp82-neo expression occurred throughout embryogenesis. In third-instar larvae …
Transcription of heat shock gene loci versus non-heat shock loci in Chironomus polytene chromosomes: evidence for heat-induced formation of novel putative ribonucleoprotein particles (hsRNPs) in the major heat shock puffs
The heat shock response of Chironomus polytene chromosomes was reexamined. The in vivo effects of heat shock on chromosomal [3H]uridine labeling, RNA polymerase II distribution and ribonucleoprotein (RNP) formation were investigated. One primary result is a clarification of the number and location of chromosomal sites strongly induced by treatment at 37 degrees C for 60 min. In total, seven major heat shock loci were identified by transcription autoradiography in Chironomus tentans: I-20A, II-16B, II-10C, II-4B, II-1C, III-12B, and IV-5C. Secondly, combining immunofluorescence with transcription autoradiography, I find RNA polymerase II occurring after heat shock at multiple chromosomal sit…
Genetic and molecular analysis of six tumor suppressor genes in Drosophila melanogaster
Six Drosophila melanogaster tumor suppressor genes causing malignant or benign tumors in specific cell types are described. The wild-type alleles of these genes are instrumental in the differentiation of particular cell types. In the homozygous state, recessive mutations in the genes interrupt the differentiation of the cells and thus cause their uncontrolled, autonomous, lethal proliferation. The tumors show all major characteristics of malignant and benign neoplastic growth. Genomic sequences of four of the genes have been identified and are currently being characterized. ImagesFIGURE 1.FIGURE 2.FIGURE 2.
GAL4-responsive UAS- tau as a tool for studying the anatomy and development of the Drosophila central nervous system
To improve the quality of cytoplasmic labelling of GAL4-expressing cells in Drosophila enhancer-trap and transgenic strains, a new GAL4-responsive reporter UAS-tau, which features a bovine tau cDNA under control of a yeast upstream activation sequence (UAS), was tested. Tau, a microtubule-associated protein, is distributed actively and evenly into all cellular processes. Monoclonal anti-bovine Tau antibody reveals the axonal structure of the labelled cells with detail similar to that of Golgi impregnation. We demonstrate that the UAS-tau system is especially useful for studying processes of differentiation and reorganisation of identified neurones during postembryonic development.