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1.
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.  相似文献   

2.
Summary The proximal half of the A (=X) chromosome ofD. madeirensis has a gene arrangement very similar to the A1 or A6 inversions found inD. subobscura. Polytene chromosome analysis of hybrids betweenD. madeirensis and strains ofD. subobscura homozygous for such inversions shows, however thatD. madeirensis has a gene arrangement different from any known forD. subobscura. These results provide evidence for a greater differentiation of the X chromosome in these species than has previously been described; it seems that the X chromosome is the only one that has undergone structural variation during the speciation process.  相似文献   

3.
Zusammenfassung Der Autor hat bereits früher über den teratogenen Effekt von Thymidin beiD. melanogaster berichtet. Die vorliegende Arbeit befasst sich mit demselben Phänomen bei anderenDrosophila-Arten undMegaselia scalaris (Phoridae). Während der teratogene Effekt beiD. simulans, D. mercatorum undD. funebris der gleiche wie beiD. melanogaster ist, tritt beiD. subobscura andMegaselia scalaris keine teratogene Wirkung auf. Die für die genannten Arten verwendete Thymidinkonzentration erweist sich fürD. hydei als stark toxisch und verhindert die Verpuppung vollkommen. Das Ergebnis zeigt, dass verschiedene genetische Systeme sehr unterschiedlich auf ein und dieselbe chemische Substanz reagieren können.

This work was done in the Institute of Biology of the University of Vienna (Head: Prof. Dr. F.Mainx) and the author is thankful for guidance and laboratory facilities.  相似文献   

4.
Summary The relative band staining intensities of ADH isoenzymes in wheat and triticale suggest alloploid genome interactions. Rye ADH is scarcely affected by anti-wheat-ADH. Despite the evolutionary divergence of their Adh genes, ADH monomers of wheat and rye form enzymatically active heterodimers in triticale.Dedicated to Prof. Dr V. Schwartz, Tübingen, on the occasion of his 70th birthday.I thank Miss Hiltrud Wambach and Miss Rita Lippert for technical assistance.  相似文献   

5.
Zusammenfassung Auf histochemischer Basis wird anTilapia (Cichlidae, Teleostei) die bereits 1880 vonSolger geäusserte und später in Vergessenheit geratene Auffassung bestätigt, dass die Verbindungsstränge zwischen den Neuromasten in den Seitenkanälen bei Knochenfischen marklose Nervenfasern, ähnlich jenen des vegetativen Nervensystems, sind.

Acknowledgments: I am most grateful to Dr.K. Reutter (Anatomisches Institut der Universität Tübingen) who undertook the histochemical investigations for this account. This work was supported by the Deutsche Forschungsgemeinschaft.  相似文献   

6.
Summary The photosensitivity of orellanine, the main toxin ofCortinarius orellanus Fries mushrooms, and its transformation to orelline via orellinine is discussed. All three substances were found in methanolic extracts ofCortinarius orellanus andCortinarius speciossimus mushrooms. The problem of homogeneity of orellanine is also discussed.Acknowledgment. The authors wish to express their gratitude to Prof. Dr W. Steglich from the Institut für Organische Chemie und Biochemie der Universität Bonn (Federal Republic of Germany) for having provided them with a sample of dried material ofC. speciossisimus.  相似文献   

7.
Susammenfassung Es wurde festgestellt, dass zwischen den Asparaginase-empfindlichen und resistenten Tumorzellen ein Unterschied bezüglich der Häufigkeit des Vorkommens von Marker-Chromosomen besteht.

We are grateful to Prof.A. Levan for his kind comments, suggestions and encouragement. We are also thankful of Prof.C. G. Schmidt for the laboratory and research facilities, to MissE. Wenderhost for helping us with the photography and to Dr.D. K. Hossfeld for making the summary in German. Our thanks are due Dr.R. Bierlig of Wuppertal-Elberfeld who provided us with the leukemic tumours.  相似文献   

8.
Summary Heterologous antibodies of the Ehrlich ascites tumor, in the presence of complement, cause a rapid drop of the ATP in the cells of this tumor. Probably there is a relation between this effect and the immune cytolysis.

FräuleinMarianne Kaestner und FrauChrista Duba danke ich für ihre gewissenhafte Mitarbeit. Die Untersuchungen wurden 1957–1959 am Max-Planck-Institut für Virusforschung in Tübingen und am Pathologischen Institut der Universität München, zum Teil mit Mitteln der Deutschen Forschungsgemeinschaft, durchgeführt.  相似文献   

9.
Summary The glutathione peroxidase activity in the plasma of rats on the 20th day of pregnancy was found to be 50% lower than in nulliparous control animals. During lactation, the level rose again but was still significantly different from that of the control rats on the 20th day post partum. The erythrocyte enzyme activity remained unchanged.Acknowledgments. We should like to thank Dr A. Wendel, Physiologisches Institut der Universität Tübingen, for his advice on carrying out the glutathione peroxidase assay.  相似文献   

10.
Summary Drosophila hydei larvae homozygous for the gene1(3)gl may survive to the age of 3 weeks, become bloated and be incapable of metamorphosis. Wild-type flies after the injection of a fragment of the1(3)gl disc, which has been previously culture in vivo for 40–500 days, also become bloated (ascitic reaction). In the hemolymph of both the advanced1(3)gl larvae and ascitic adult hosts the accumulation of a specific protein is observed.Acknowledgments. This work was supported by the Swiss National Science Foundation under Grant No.3.792-0.76 and the Georges und Antoine Claraz-Schenkung. We thank Prof. H. Gloor, University of Geneva, and Prof. P.S. Chen, University of Zürich, for advice and criticism.  相似文献   

11.
Summary The fronds of the fernAsplenium trichomanes contain kaempferol 3,7-dirhamnoside (1) and the new compounds kaempferol 3-O-a-rhamnoside-7-O-a-arabinoside (2) and kaempferol 3-O-a-arabinoside-7-O-a-rhamnoside (3). The presence of the above flavonoids has been shown by spectroscopic methods and chemical degradations.Acknowledgments. The author thanks Prof. H. Wagner (Institut für pharmazeutische Arzneimittellehre der Universität München, München) for a sample of kaempferol 3,7-dirhamnoside, Dr K. R. Markham (Chemistry Division, D.S.I.R., Petone, New Zealand) for a gift of pectinase and Mr A. D'Urso (Botanic Institute, University of Catania) for help in acquiring the plant material.  相似文献   

12.
Zusammenfassung Chromosomen von 12 Männchen und 12 Weibchen vonRattus rattus wroughtoni sowie 2 Weibchen vonRattus rattus wurden untersucht und es wurden überall 38 Chromosomen gefunden, verursacht durch Robertsonische Verbindung von 4 akrozentischen Paaren vonRattus rattus mit 42 Chromosomen.

Authors respectfully thank their teacher Prof.S. P. Ray-Chaudhuri for constant encouragement. The financial assistance provided by University Grants Commission, India, is also gratefully acknowledged.  相似文献   

13.
Summary In the female Indian frog,Rana tigrina (2n=26; NF=52), the female is heterogametic. The heterochromosomes (ZW) are morphologically indistinguishable, but the W chromosome proves by C-banding analysis to be entierly heterochromatic.Acknowledgment. S.C. is grateful to Prof. G.K. Manna, Zoology Department, Kalyani University, Prof. Archana Sharma, Botany Department, Calcutta University and to Prof. T. Sharma, Zoology Department, Banarus Hindu University for encouragements. He is also thankful to Prof. D.K. Choudhuri, Burdwan University for support.  相似文献   

14.
Zusammenfassung Ein wässeriger Extrakt einer besonderen Krabbenart (Lophozozymus pictor) erweist sich als toxisch gegenüber HeLa-Zellen. Es kommt zu Umwandlungen der Zellform sowie des Cytoplasmas. Die Reaktion scheint leicht erfassbar und ist für einen Toxizitätstest besser geeignet als der bis jetzt verwendete Mäusetest.

We thank Prof.J. E. Gardiner for supporting the project and the Department of Bacteriology, University of Singapore, for the supply of HeLa cells.  相似文献   

15.
Summary Comparison of superoxide dismutase activity in homogenates of wild and vestigial strains ofD. melanogaster revealed a lower enzyme activity in the short-living vestigial strain.Acknowledgments. We are indebted to Prof. M. Olszewska for giving us fly specimens. This work was partly supported by the project No. R. III. 13. 2. 4.  相似文献   

16.
Zusammenfassung Die Saugtätigkeit der JassideEmpoasca flavescens (F.) führte zu einer um 44% gesteigerten Respiration von geschädigten, anfälligen Rizinuspflanzen (Ricinus communis L.) im Vergleich zu 11.6% und 3.7% bei Pflanzen einer toleranten und resistenten Sorte. Diese Zunahme war bei der anfälligen Sorte verknüpft mit einer gesteigerten Anhäufung von Rohrzucker, Gesamtstickstoff und Gesamtaminosäuregehalt.

This study formed part of the Doctoral Thesis submitted to the University of Madras and financial support was given by the Council of Scientific and Industrial Research, Government of India, New Delhi. Grateful appreciation is extended to Prof. A. R.Seshadri, Agricultural College and Research Institute, Coimbatore, India and Prof. R. H.Painter, Kansas State University, Kansas, U.S.A. for their valuable suggestions made during the course of the study.  相似文献   

17.
Resumen DelAspergillus fonsecaeus (N. R. R. L. 67, O 16-1) se han aislado dos nuevos pigmentos que fueron identificados como monometil éteres de la fonsecina y de la rubrofusarina, respectivamente.

Acknowledgement. The authors thank Prof.S. Shibata of Tokio University for reference compound, the Cátedra de Microbiologia Industrial of their Faculty for fermentation work and the Consejo Nacional de Investigaciones Cientificas y Técnicas for a grant.  相似文献   

18.
Summary Survival time ofDrosophila buzzatii adults on anOpuntia (prickly pear) medium was significantly longer than that of its nearest relativeD. serido. A significant difference was also found betweenD. buzzatii adults from two experimental populations, one of them fed onOpuntia rots for more than two years and another one kept on standardDrosophila medium for the same period of time. These results suggest that adult selection may be taking place in cactiphilicDrosophila in their natural habitats and could be responsible for the niche differentiation betweenD. buzzatii andD. serido.This work has been supported by the Comisión Asesora de investigación Científica y Técnica, Spain, by funds to project 4514/79 awarded to the third author.  相似文献   

19.
Summary Treatment of neonatal mice with an antiviral factor, (AVF), obtained from the leaves ofMelia azederach L. protected them against lethal encephalitis caused by Tacaribe virus inoculation. The degree of protection obtained varied from 66% to 100% depending on the virus dose. Similarly, administration of AVF to nursing mothers protected their offspring from developing virus encephalitis. AVF does not directly inactivate Tacaribe virus; it inhibits an early step (s) in the replication process in cell cultures.Dedicated to Prof. Luis Leloir on his 80th birthday.Acknowledgment. This study was supported by Grant 9353/84 from the Consejo Nacional de Investigaciones Cientificas y Técnicas (CONICET), Argentina.  相似文献   

20.
Summary The longitudinal and circular muscle cells of the alimentary canal of the oligochaete wormBranchiura sowerbyi show intercell couplings. These couplings occur between adjoining cells of the same or of the other orientation.We wish to thank Dr S. Kawaguti, Prof. emeritus of Okayama University, for his kind advice.  相似文献   

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