An attempt to induce crossing-over in males ofDrosophila melanogaster with ovarian extract

Zusammenfassung Von zwei früheren, sich widersprechenden Befunden wird einer gestützt: Ovarialextrakte vonDrosophila lösen in Männchen keine «crossing-over» aus.

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The author wishes to express her gratitude to Dr. P. G.Kale for guidance and to Prof. S. P.Ray-Chaudhuri for the facilities provided.     

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.

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

Properties of the larval hemocytes ofDrosophila melanogaster

Summary Contrary to Srdi and Gloor's report, we find crystal cells (cc) in the lymph glands ofD. melanogaster larvae; the size and number of inclusions in the cc cannot be used to distinguish the 2 sibling species,D. melanogaster andD. simulans; cc in the hemocoel are not phagocytic cells; the surface properties of the lamellocytes are consistent with their derivation from plasmatocytes and not cc.Supported by grant No. CA16619 awarded by the National Cancer Institute, DHEW, USPHS.     

A female-sterile mutant(deep orange) ofDrosophila melanogaster Increasing isoxanthopterine content

Zusammenfassung Der Bestand an fluoreszierenden Stoffen in verschiedenen Entwicklungsstadien der Weibchen-steril-Mutantedeep orange wurde papierchromatographisch festgestellt. In allen geprüften Stadien vondor/dor- undClB/dor-Weibchen ist mehr Isoxanthopterin nachweisbar als bei +-Weibchen. Bei Männchen der Mutante findet sich in Puppenstadien weniger Isoxanthopterin als bei +-Männchen; nur bei frisch geschlüpften Fliegen entsprechen sich normale unddor-Männchen in ihrem Isoxanthopterin-Gehalt. Beidor/dor- unddor/Y-Tieren sind ausserdem noch andere Pterine betroffen. So zeigen die Köpfe derdor-Mutante weniger rote Pigmente, sowie mehr «Xanthopterin» und «Sepia-Pterin» als Fliegen des Wildtyps, dagegen kommen HB₁ und HB₂ in normaler Menge vor. Im Kopf der heterozygoten Weibchen werden für alle diese Pterine Werte gemessen, die sogar den Wildtypus beträchtlich übertreffen. Beidor/dor unddor/Y findet sich in den Malpighischen Gefässen eine stark erhöhte Konzentration an fluoreszierenden Stoffen.     

Temporal and spatial distribution of phosphoglucomutase (PGM) polymorphism in natural populations ofDrosophila melanogaster

Summary Drosophila melanogaster adults were collected for several years in various localities of Italy. The frequencies of thePgm electrophoretic alleles were determined and the similarity of the configuration of allelic frequencies observed. It was concluded that the PGM electrophoretic polymorphism could be maintained by random genetic drift in the natural populations studied only if the effective breeding size (N _e ) during the bottle-neck period is about 5000.I am grateful to Prof. D. Sperlich and Prof. W. Seyffert for their kind hospitality during my sojourn as Research Fellow of the Alexander von Humboldt Foundation in the Institute of Biology II at the University of Tübingen (FRG) where the final version of this paper has been done. The technical assistance of Mr A. Micheli is also acknowledged.     

Studies of selective mating using the melanistic mutants ofDrosophila melanogaster

Résumé L'observation directe a montré qu'il n'y a pas d'isolement sexuel entre le typesauvage et les mutants mélaniquesebony etblack deDrosophila melanogaster, mais il existe de notables différences entre l'activité sexuelle et motrice des mâles des trois génotypes. L'importance sélective de ces différences est soulignée.     

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.

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

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.     

Studies of selective mating using the sex-linked mutantsWhite andBar ofDrosophila melanogaster

Résumé L'observation directe montre qu'il n'y a pas d'isolement sexuel entre le typesauvage (Canton special) et les mutantsBar etwhite deDrosophila melanogaster. L'activité sexuelle des mâles est nettement moindre chezwhite etBar. Par contre les activités locomotrices ne semblent pas inférieures.     

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.

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

Content and synthesis of γ-aminobutyric acid in the larval brain ofDrosophila melanogaster

Zusammenfassung Papierchromatographische Untersuchungen an verpuppungsreifen Larven vonDrosophila melanogaster zeigten, dass der relative Gehalt an -Aminobuttersäure im Gehirn rund zweimal höher ist als in der ganzen Larve. Mittels Isotopentechnik wurde eine aktive Synthese der -Aminobuttersäure im Hirnhomogenat nachgewiesen.

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This investigation was supported by grants from the Schweizerischer Nationalfonds zur Förderung der wissenschaftlichen Forschung and the Karl-Hescheler-Stiftung.     

Effects of the inhibitor of xanthine dehydrogenase, 4-hydroxypyrazolo(3,4 d)pyrimidine (or HPP) on the red eye pigments ofDrosophila melanogaster

Riassunto Esemplari diD. melanogaster di tipo selvaggio o del mutantest, allevati su terreno contenente l'inibitore della xantino-deidrogenasi 4-idrossipirazolo-(3, 4 d)pirimidina (HPP), presentano l'occhio colorato in arancione scuro o in giallo. Cromatograficamente è stato possibile precisare che siffatte modificazioni dipendono dalla diminuzione dei pigmenti rossi contenuti nell'occhio, diminuzione che risulta molto più accentuata nel caso della neodrosopterina, il cui colore proprio è più rosso di quello degli altri pigmenti.

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This research was supported by the Consiglio Nazionale delle Ricerche, Rome (Italy).     

A duplication involving the esterase 6 locus in a wild population ofDrosophila melanogaster

Summary A possible duplication of the esterase 6 locus inD. melanogaster is reported. Recombination between the duplicated loci is about 30%.     

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.     

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.