Ecdysteroids inLimulus larvae

Summary Free ecdysteroids were extracted from intermolt and premolt larvae ofLimulus polyphemus in the first posthatch stage, purified by TLC and HRLC, and assayed by RIA and theLimulus bioassay 20-hydroxyecdysone appears to be a principal ecdysteroid and occurs at least 3 times higher a concentration in premolt vs intermolt animals.Supported by NSF grant GB-40620.Acknowledgments. We are indebted to Prof. G. R. Wyatt for the antibody, Prof. K. Nakanishi for use of his laboratory for HRLC separations, and to Dr David King for the³H-ecdysone and for performing radio-TLC analyses.     

Experiments on sexual isolation between Chilean and European strains ofDrosophila subobscura

Summary Males and females of Chilean strains ofDrosophila subobscura exhibit a pronounced tendency toward homogamic mating. This tendency shows a clear relation to the distance between the geographic localities from which the respective strains came. Nevertheless, when the Chilean flies are confronted with European strains, the ethological isolation is observed in some cases but not in others, depending on the geographic origin of the strains.Acknowledgments. This work has been partially supported by grants from the Univ. of Chile (Project B 729-8345) and PNUD/UNESCO (RLA 78/024). We are most grateful to Prof. D. Sperlich of the University of Tübingen who provided theD. subobscura strains from Tübingen and Sicily, and Prof. A. Prevosti from the University of Barcelona and R. de Frutos from the University of Valencia who provided the strains of Mallorca and Almería. We are finally obliged to Mr E. Zárate for his technical assistance.     

Hemolymph proteins in an ascitic condition,induced by lethal1(3)gl tumorous tissue inDrosophila hydei

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.     

A specific protein in the genusRhynchosciara (Diptera,Sciaridae)

Summary Proteins immunologically related toRhynchosciara americana larval protein 10 occur in the hemolymph and ovaries of five different fly species of the genusRhynchosciara. Electrophoretic analyses showed these proteins to have a mol.wt similar to that of theR. americana protein 10 (43,000), e.g. theR. hollanderi protein 44,300, theR. milleri protein 45,500.     

Cytotaxonomy of the myobatrachid frogs of the genusLimnodynastes

Summary 4 of the 5 species ofLimnodynastes of theperoni group show 2n=24. Onlysalmini has 2n=22, thus resembling the species ofPlatyplectron (thedorsalis andornatus complexes) which all show 22 chromosomes. This 2nd group also includes species (ornatus) with very low DNA amounts. From a karyological point of view, the species of thePlatyplectron (plus eventuallysalmini) group appear more differentiated than the species of theperoni group, from which they have probably arisen.Research partly supported by a contribution from C.N.R., Rome.     

Myosin heavy chains in fast skeletal muscle of chick embryo

Summary The peptide map obtained by electrophoresis after digestion of purified myosin heavy chains from pectoralis muscle of embryonic chicken with theStaphylococcus aureus V8 protease, produces a peptide pattern very similar but not identical to that of adult fast myosin. In fact, some components that are present in a small amount in the map of slow adult myosin are visible in the embryonic pattern.Acknowledgments. I wish to acknowledge the enthusiastic encouragement of Dr Ugo Carraro and the help of Prof. Stefano Schiaffino's group and of Dr Marcello Cantini for embryonic tissue isolation. The skillful technical assistance of Mr Silvio Belluco is also gratefully acknowledged. This work was supported in part by a grant of Muscular Dystrophy Association of America to Prof. Massimiliano Aloisi.     

Localization of wheat germ agglutinin receptor sites on yeast cells by scanning electron microscopy

Summary WGA receptor sites on the surface ofSaccharomyces cerevisiae cells pretreated with an - mannanase were localized by gold granules labelled with WGA. The receptor sites were found on the bud scars, the mother cell-bud junction (chitin) and the bud, but not on the mother cell.Acknowledgment. We thank Prof.C. E. Ballou for supplying theArthrobacter strain GJM-1 and MrsM. Weber for the photographic work.     

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.     

Mikrobiologische Spaltung razemischer Steroide. Synthese vond-Aldosteron

Summary A racemic intermediate in the total synthesis ofd, l-aldosterone, thed, l-20-oxo-pregnene derivative I, was converted by incubation with a mold hydroxylating in the 21-position into thed-20-oxo-21-hydroxy-pregnene derivative II, whereas thel-antipode of the starting material remained unchanged. This stereospecific microbiological reaction, comprising a separation of racemic modifications, represents the last remaining step in the synthesis of naturald-aldosterone.Other microbiological conversions of racemic steroids, dehydrogenation and hydrogenation, were also shown to proceed only with thed-enantiomer, leaving thel-form of thed, l-substrate intact.The advantages of this new microbiological method for the resolution of racemic modifications during the total synthesis of steroids are discussed.     

The sterols of two hadromerida sponges

Summary Sterols were extracted and identified from 2 marine sponges,Aaptos aaptos andSuberites domuncula. The sponges contained conventional C₂₆–C₃₀ sterols with a saturated ring system. Minor amounts of cholest-7-en-3-ol and cholesterol were also present. Cholestanol and 24-ethylcholestanol were the major components of the sterol mixtures.We thank Prof. L. Boniforti (Istituto Superiore di Sanità, Roma) for CG-MS analysis, Prof. R. Pronzato (Istituto di Zoologia dell'Università di Genova) for identifying the sponges and A. Senatore for G.C. measurements. This research was supported by grants of Ministero P.I. and C.N.R.     

Tissue distribution and substrate specificity of an epoxide hydrase in the gypsy moth,Lymantria dispar

The stereoselectivity of the enzymatic hydration of disparlure, the pheromone for the gypsy mothLymantria dispar, and for twomeso analogues was determined. A single expoxide hydrase (EH), present in various male and female moth tissues, converted disparlure and the analogues to their respectivethreo-(R,R)-diols with high stereoselectivity as determined by analysis of the diols by chiral phase capillary gas chromatography. This EH recognizes thecis-nature of the dialkyl oxirane, but shows poor discrimination of the two alkyl chains.     

Rana esculenta complex: An experimental analysis of lethality and hybridogenesis

Summary Experiments designed to analyze the lethality and hybridogenesis in the European green frog complex have yielded the following results: 1. As a rule the inter-se cross ofRana esculenta is lethal, but several crosses have produced fully viable progeny. The frequency of such break-through crosses appears to be related to parental population structure. 2. Parabiotic joining of lethal to viable embryos indicates that manifestation of the lethal effect is autonomous. There is, however, a 16–18% increase in the life span of the lethal partner. 3. Studies of LDH isozyme patterns revealed that thelessonae-specific alleles coding for the B^a and B^c subunits can be passed to the F₁ progeny from a parental female or male of theesculenta phenotype. This demonstrates that there is no total elimination of thelessonae genome in theesculenta germ cells. 4. Immunologically, offspring from the inter-se cross ofR. esculenta show a closer relationship to theridibunda than to theesculenta phenotype. Variations of antigenic protein patterns suggest the possibility of chromosomal recombination betweenlessonae andridibunda in theesculenta hybrid. These results are confirmed by two-dimensional electrophoretic analysis of proteins in the oocytes of the three frog phenotypes.This work was supported by grants from the Swiss National Science Foundation and the Georges and Antoine Claraz Schenkung.     

Étude cytologique d'une translocation chromosomeY-autosome chez la souris

Summary A male mouse with one translocation involving theY-chromosome has been observed in the F1 offspring of a male mouse given 300 R of X-irradiation. 6 types of spermatocytes were recorded. Our observations appear to confirm that the acrocentricX of the mouse associates end-to-end with theY at its centromeric end.     

The effect of leafhopper infestation on the respiration of castor bean varieties in relation to their resistance toEmpoasca flavescens (F.) (Homoptera: Jassidae)

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.

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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.     

Two novel metabolites ofAspergillus fonsecaeus

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.

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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.     

A non-peroxide norsesterterpene from a marine spongeHyrtios erecta

Summary A new norsesterterpene, hyrtial4, and known sesterterpenes,1–3, have been isolated from an anti-inflammatory active crude extract of the spongeHyrtios erecta.This sponge,Hyrtios (Heteronema) erecta Keller 1889, collected in 1980/81, from Tonga was extremely abundant in the Vava'u Is. Group.We thank Prof. R. Jacobs and his research group at UCSB for this data.     

Quinone tanning in Agnatha

Summary The buccal teeth and notochordal sheath of the marine hagfish,Petromyzon marinus (L.) are phenolically tanned like the cuticle of insects and other arthropods.Acknowledgments. We are grateful to Dr Bill Lovejoy for generously supplyingP. marinus L. A.R.V. is thankful to Prof. R.G. Michael for encouragement.Previously called A. Sannasi.     

Superoxide dismutase and life span ofDrosophila melanogaster

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.     

Dynamic biomagnetism associates bean seeds

Summary Water uptake by bean seeds (Phaseolus vulgaris) over 4 h in 4 adjacent Faraday cages and in 4 similar, but mumetal-lined, Faraday cages disclosed comparable interactional patterns among both cage types. This indicates a role of dynamic, or fluctuating, biomagnetic fields. An inverted relationship over time between the 2 cage types is probably due to geomagnetic attenuation.I wish to thank Carol S. Chow and Kate M. Scow for overseeing the collection of data, and Profs J.A. Lippincott and R.C. Gesteland of the Dept. of Biological Sciences and Prof. M.R. Brodwin of the Dept. of Electrical Engineering, Northwestern University, for helpful discussions. This study was aided by grants No. GB-41392X, No. BMS73-0191-A01, and No. BMS73-01591-A02 from the National Science Foundation.     

Electrophysiological characteristics ofBombyx mori L. ventral nerve cord (effect of sodium and potassium on the membrane potential)

Summary Na⁺ and K⁺ effects on the resting cellular membrane potential of desheathed ganglia of theBombyx mori L. ventral nerve cord have been studied. The cells are depolarized by high concentrations of external potassium ions in the same way as in vertebrates, mollusca and crustacean cells. The possibility that the behaviour of the resting potential is not only influenced by the potassium equilibrium potential, but also by the conductances to other ions, is discussed.The authors are indebted to Prof V. Capraro, Drs B. Giordana and F. Sacchi for helpful comments and criticism.