An improved method for the collection of large numbers of inseminated eggs ofDrosophila melanogaster

Zusammenfassung Es wird eine verbesserte Methode beschrieben, mit der innerhalb einer Sammelperiode von 3 min etwa 50-100 frisch besamte Eier vonDrosophila melanogaster gewonnen werden können. Verglichen mit den bisher üblichen Sammelperioden von 10, 30 oder mehr min erhält man wesentlich stadienhomogenere Gelege. Eine weitere Verkürzung der Sammelperiode unter 3 min ist wegen der stark abnehmenden Anzahl Eier je Gelege nicht möglich. Vorausgesetzt, dass alle Störungen der Fliegen durch Erschütterungen, Licht, Temperaturschwankungen usw ausgeschaltet werden, können z.B. für strahlenbiologische Experimente zahlreiche 3-min-Gelege im Laufe von 6 oder mehr Stunden gewonnen werden.

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Work supported by Schweizerischer Nationalfonds zur Förderung der wissenschaftlichen Forschung and Jubiläumsfond 1930 der ETH.     

Mating patterns of virgin and inseminated Drosophila melanogaster of different alcohol dehydrogenase (Adh) genotypes

Female choice mating experiments showed virgin female D.melanogaster of the 3 Adh genotypes chose heterozygous (AdhF/AdhS) males most commonly. Inseminated females chose mates randomly, but the likelihood of a female remating was genotypically dependent.     

An improved bioassay method for kinins

Zusammenfassung Unter Ausnützung der besonderen Empfindlichkeit der Femoralarterie des Kaninchens für Kinin wurde die autoperfusionierte Hinterextremität beobachtet. Intraarterielle Injektion von 0,5 ng synthetisiertem Bradykinin ergab eine messbare, dosisabhängige Vasodilatation in fast allen Versuchstieren. Dieses Kreislaufpräparat erweist sich zur Kinin-Bestimmung als besonders geeignet.     

Toxicity of ouabain on Drosophila melanogaster

Summary Ouabain, also called g-strophantin, is an inhibitor of the Na⁺/K⁺-activated plasma membrane ATPase. Treatment of Drosophila melanogaster with 3–6 mM of this substance leads to a markedly reduced survival of the flies.     

An improved electrophoretic method for a screening program for haemoglobinopathies

Summary A method for a screening program for haemoglobinopathies in a starch agar gel mixed with saponin is presented. Normal and abnormal blood containing haemoglobins S, C, I, M Boston, D Punjab, beta thalassaemia major and beta thalassaemia minor, were applied, in a tray with the capacity for 100 samples. The electrophoresis was performed in 45 min using 300 V. This method offers special advantages for the examination of a large number of samples, using a small amount of whole blood and without the previous preparation of haemoglobin solution.Acknowledgments. We would like to express our gratitude to Dr C. Daghlian and Dr Lewis J. Greene for their valuable suggestions. We also thank the Conselho Nacional do Desenvolvimento Científico e Tecnológico, CNPq, for financial support.     

An improved method for estimating the activity of a mouse with the photoswitch

Summary A new method for estimating the activity of a mouse by means of the photoswitch is contrived. This device can follow the activity with high fidelity and notable sensitivity, as compared with the conventional method.     

An improved method for estimating the activity of a mouse with the photoswitch

A new method for estimating the activity of a mouse by means of the photoswitch is contrived. This device can follow the activity with high fidelity and notable sensitivity, as compared with the conventional method.     

Enzymes of Sphingolipid metabolism in Drosophila melanogaster

Sphingolipids are important structural components of membranes that delimit the boundaries of cellular compartments, cells and organisms. They play an equally important role as second messengers, and transduce signals across or within the compartments they define to initiate physiological changes during development, differentiation and a host of other cellular events. For well over a century Drosophila melanogaster has served as a useful model organism to understand some of the fundamental tenets of development, differentiation and signaling in eukaryotic organisms. Directed approaches to study sphingolipid biology in Drosophila have been initiated only recently. Nevertheless, earlier phenotypic studies conducted on genes of unknown biochemical function have recently been recognized as mutants of enzymes of sphingolipid metabolism. Genome sequencing and annotation have aided the identification of homologs of recently discovered genes. Here we present an overview of studies on enzymes of the de novo sphingolipid biosynthetic pathway, known mutants and their phenotypic characterization in Drosophila.Received 14 June 2004; received after revision 15 August 2004; accepted 21 August 2004     

An improved method for the isolation of eosinophilic leukocytes from normal human blood

Summary A relatively short and simple method for the isolation of the eosinophils from normal human blood is reported. With a recovery of about 45–55%, cell preparations, showing a degree of purity of 90–98%, are obtained. The isolated cells are morphologically intact and viable, as assessed by the trypan blue exclusion test and by active phagocytosis.The authors are indebted to the Schweizerischer National-fonds zur Förderung der wissenschaftlichen Forschung for financial support.