Preadult lethality in four populations ofDrosophila melanogaster treated with formaldehyde

Summary Samples from 4 populations ofD. melanogaster were treated with formaldehyde by the larval feeding method, and induced lethality was scored. The results showed relevant differences among the populations analyzed.     

Kynurenine localization in the egg ofDrosophila melanogaster

Zusammenfassung Papierchromatographische und fluoreszensmikroskopische Untesuchungen von Ovarien der Wildtypen und der Vermilion- und Cinnabar-Mutanten vonDrosophila zeigen, dass sich Kynurenin (der Hauptbestandteil der fluoreszierenden Komponente des Eies) in den proteinhaltigen Dotterschollen des reifenden und des reifen Eies befindet.

---

---

Supported in part by NIH grant No. GM 14891 and a grant from the Research Foundation of the State University of New York.     

Abnormal organization of ovarian follicles in the mutantl(1)su(f) mad-ts ofDrosophila melanogaster

Summary The morphology of ovarian follicles in the temperature-sensitive female-sterile mutantl(1)su(f) ^mad-ts has been studied by means of light and electron microscopy. As the follicle cells gradually degenerate at the restrictive temperature (29°C) the follicles become increasingly disorganized with respect to shape and polarity.Acknowledgments. This work was supported by the Deutsche Forschungsgemeinschaft (SFB 46). We wish to thank Mrs R. Koppa for excellent technical assistance and Mrs G. Mahlke for photographic work. We are also indebted to Dr D. Zissler, Dr E. Gateff and Prof. K. Sander for many helpful suggestions.     

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.

---

---

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

Changes of chromosome number in cells ofDrosophila melanogaster cultured in vitro

Riassunto Cellule embrionali diD. melanogaster, coltivate in vitro fino a 120 h, presentano un progressivo aumento delle variazioni dei numeri cromosomici interessanti principalmente il I e il IV paio di cromosomi.     

Crystal cell pattern modification in a melanotic tumor strain ofDrosophila melanogaster

Summary 3rd instar larvae of the melanotic tumortu-pb strain ofDrosophila melanogaster hold a lower number of free-circulating crystal cells in their hemolymph than the wild type ones. This pattern could result from an abnormal retention of mature crystal cells in the hematopoietic organs, as the strong hemocyte melanization inside the lymph glands of heat-treatedtu-pb larvae seems to demonstrate. Melanotic tumor formation and modification of the crystal cell pattern may be related.     

Genetic and autoradiographic studies of tritiated thymidine in testes ofDrosophila melanogaster

Zusammenfassung Die Aufnahme von H³-Thymidin in 16 h alte männliche Larven vonDrosophila melanogaster wurde autoradiographisch verfolgt und die mutagene Wirkung des einverleibten H³-Thymidin durch die Bestimmung der Häufigkeit der geschlechtsgebundenen rezessiven Mutationen gemessen. Es zeigte sich, dass das der männlichen Larve derDrosophila melanogaster verabreichte H³-Thymidin eine bedeutende Häufigkeit der Mutationen verursacht.

---

---

Supported in part by Grant G-6097 of the National Science Foundation.     

Regeneration ofDrosophila melanogaster male leg disc fragments in sugar fed female hosts

Zusammenfassung Fragmente von Beinimaginalscheiben regenerieren nicht, wenn sie in restriktiv ernährten Wirten kultiviert werden, wo Proliferation unterdrückt wird. Die Regenerationshemmung ist reversibel, da solche Fragmente in gut ernährten Wirtslarven normal regenerieren.     

The cell cycle of an established line ofDrosophila melanogaster cells in vitro

Riassunto La durata media delle fasi del ciclo cellulare (G₁, S e G₂) e del tempo di generazione totale (G _T ) in una linea stabilizzata di cellule diDrosophila melanogaster risulta essere rispettivamente di 1.8, 10.0, 7.2 e 18.8 ore.     

Genetic load and effective size of natural populations ofDrosophila melanogaster in Korea

Summary The effect of 750 second chromosomes ofDrosophila melanogaster on viability was studied. 19.3% of them proved letal or semilethal (=drastics) in homozygous condition. Compared to data obtained in previous years at the same sampling site, a significant frequency decrease of drastics during the past decade could be observed. The dynamic processes taking place in the Korean wild populations ofD. melanogaster are discussed.Acknowledgment. This work was supported by a research grant from the Korean Science and Engineering Foundation.     

Xanthine dehydrogenase in the biosynthesis of the eye pterin pigments ofDrosophila melanogaster

Riassunto Il trattamento con HPP di mutanti SE diDrosophila melanogaster ha dato la fenocopia biochimica del doppio mutante MAL/SE (diminuzione della sepiapterina, aumento delle biopterine e, nei maschi, assenza della isoxantopterina con accumulo del precursore 2-amino-4-idrossipterina). Si discute il ruolo dell'enzima XDH nel metabolismo in istudio.

---

---

We are indebted to Wellcome Italia S.p.A., Rome, for a generous gift of HPP (Allopurinol®).