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.     

C-banding pattern on the chromosomes of the Japanese house shrew,Suncus murinus riukiuanus,and its implication

Summary The C-band on the chromosomes of the Japanese house shrew,Suncus murinus riukiuanus (Insectivora), was studied. Various types of C-banding pattern were found in the genome of this subspecies. Such banding patterns could be useful for an understanding of autosome and sex-chromosome polymorphisms withinS. murinus.Acknowledgment. The authors are very grateful to Prof. T. Wasano of Fukuoka University for his encouragement, Dr K. Ogawa of Fukuoka University, the Nohara family for help in collecting specimens, and Prof. E.W. Jameson, Jr, University of California, Dr J.W. Bickham and his students of Texas A & M University for comments.     

The structure of jhanilactone

Summary The molecular structure and absolute configurationI was assigned to jhanilactone, a new lactone fromEupatorium jhanii Robinson, on the basis of X-ray crystallography and circular dichroism data.Part 37 in the series Chemistry of the Composites. For Part 36, see A.G. González, J. Bermejo, I. Cabrera, G.M. Massanet, H. Mansilla and J.M. Amaro, Phytochemistry, submitted for publication.Acknowledgment. We thank Prof. S. García-Blanco, Instituto Rocasolano, Madrid for the use of an X-ray diffractometer and Prof D.N. Kirk, Westfield College, London for the CD data.     

Seasonal variations in the fertilizing capacity ofBufo arenarum (Amphibia Anura) spermatozoa

Resumen La capacidad fecundante de los espermatozoides deBufo arenarum decae más rápidamente en verano que en invierno. Ello probablemente sea debido a la presencia, durante el invierno, de factores testiculares de protección.

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This work was supported by a grant from the Consejo Nacional de Investigaciones Cientificas y Técnicas de la República Argentina and by the Population Council grant No. 71.68 awarded to the Consejo Nacional de Investigaciones Cientificas y Técnicas to be administered by the Instituto de Biología, Facultad de Bioquímica, Química y Farmacia, Universidad Nacional de Tucumán.

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The author is most grateful to Dr.F. D. Barbieri for his kind discussion and helpful advice in the course of the present study.     

Marine indoles of novel substitution pattern from the acorn wormGlossobalanus sp.

Summary 4,6-Dibromoindole and 4,6-dibromo-2-methylindole have been isolated from the acorn wormGlossobalanus sp. The biosynthetic implications of this finding are discussed.We wish to thank Prof. Paul J. Scheuer, University of Hawaii for his encouragement and for use of his facilities during spectroscopic work. T.H. gratefully acknowledges the giving of a travel grant by the University of the Ryukyus Foundation for International Exchange.     

Absorption of glycine,L-alanine and L-phenylalanine in the midgut of the larvae ofBombyx mori

Summary A net absorption of glycine, L-alanine and L-phenylalanine occurs across the isolated midgut of the larvae ofBombyx mori. Although glycine and L-phenylalanine are not metabolized, L-alanine is converted by the midgut and has a metabolic effect on the transepithelial electrical potential difference of the tissue.Acknowledgments. We are very much indebted to Prof. V. Capraro for helpful advice and criticism. We are also grateful to Prof. G. Reali for his interest and support of this research.     

Chromosomal translocations in 2 Italian populations ofReticulitermes lucifugus (Rossi) (Insecta,Isoptera: Rhinotermitidae)

Summary The chromosomes of 2 Italian populations ofReticulitermes lucifugus (Rossi) were studied in both spermatogonial and oogonial divisions. The diploid chromosome complement is 2=42. All the first meiotic metaphases in Sardinian males show a complex translocation arranged in chains of 4 bivalents. The Apulian males show either 21 bivalents or 19 bivalents and a chain of 2.The authors express their thanks to Prof. A. Springhetti for his kind help in supplying the materials and for criticism in preparation of this paper, and to Prof. G. Colombo for valuable advice and criticism.     

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.     

A chromosome study ofScarites occidentalis (Coleoptera,Caraboidea)

Summary Scarites occidentalis has 2n=41 (females 2n=42), n=19+X₁X₂Y. This multiple sex-chromosome system and other karyotypic characteristics suggest that this species andS. buparius share a recent common ancestor in which the sex trivalent was probably originated.Thanks are due to Dr N. Virkki for his valuable comments and his help with the English, to Dr Ramos and Dr Aparicio for discussion and advice, to Dr F. Hiraldo and M. Mañez for collecting the specimens. This work has been supported by a postdoctoral fellowship of the Consejo Superior de Investigaciones Científicas.     

Tissue- and stage-specific RNA patterns inDrosophila as revealed by gradient formamide gel electrophoresis

Summary The in vitro labeled RNAs in the accessory glands from male adults, and in the salivary glands and fat body from developing larvae ofDrosophila melanogaster were separated on linear gradient acrylamide gels in formamide. The patterns appear to be tissue- and stage-specific, and several lines of evidence indicate that the visualized radioactive bands include both hnRNA and messages.Acknowledgments. The financial support by the Swiss National Science Foundation and the George and Antoine Claraz-Schenkung is gratefully acknowledged. I thank Prof. Max Birnstiel for providing me with the sea urchin histone mRNA and Prof. Martin Billeter for providing me with the rabbit globin mRNA as RNA markers.     

Autoradiographic studies on RNA synthesis and transport in the Salivary gland ofLygaeus sp. (Hemiptera-Lygaeidae)

Summary Autoradiographic studies using³H-uridine in the salivary gland of adultLygaeus sp. were carried out. The gland cell nuclei, particularly the multiple nucleoli, are the sites of incorporation of the label exhibiting RNA synthesis. The labelled molecules (RNA) are transported to the cell cytoplasm and then into the gland lumen in which no turnover of the radioactivity is observed.I am grateful to my teacher, Prof. P. S. Ramamurty, School of Life Sciences, University of Hyderabad, for his constant inspiration. Grateful acknowledgement is made to Prof. J. P. Thapliyal, Dept of Zoology, B. H. U. for encouragement and to Dr Om Prakash, Dept of Biochemistry, B. H. U. for his valuable criticism.     

Protease in ascidian endostyle

Summary A proteolytic activity at pH 7.6 was determined in the endostyle of the ascidianStyela plicata. With the use of specific inhibitors, it was demonstrated that a tryptic-like alkaline protease, TLCK-dependent, is involved.The author wishes to thank Prof. A Minganti for his critical revision of the text.     

Cell proliferation in the rat pituitary gland: A mechanism of control in prolactin cells

Summary We investigated the relationship between prolactin content and DNA replication in the anterior pituitary gland. Thymidine incorporation in pregnant rats is significantly lower than in virgin controls. This is accompanied by a decreased activity of DNA polymerase. Sulpiride administration to pregnant rats enhances thymidine incorporation to levels similar to virgin controls. The results indicate a negative feedback between prolactin content and DNA synthesis in the rat anterior pituitary gland.We are grateful to Prof. Carlos J. Gómez for the opportunity to perform this work. These studies were supported by PLA-MIRH 99.178.1.78, by the Consejo Nacional de Investigaciones Científicas y Técnicas and by the Comisión Nacional de Energía Atómica (Argentina).     

DNA synthesis in the pituitary gland of the rat: Effect of sulpiride and clomiphene

Summary Sulpiride administration to rats releases prolactin and increases DNA replication in the anterior pituitary gland. Clomiphene prevents the stimulation of DNA synthesis produced by sulpiride, but does not affect prolactin release from the gland. These findings suggest that the intracellular prolactin content of the anterior pituitary gland plays a role in the regulation of DNA synthesis through a mechanism mediated by oestrogens.This work was supported by PLAMIRH 99.178.1.78, by the Consejo Nacional de Investigaciones Científicas y Técnicas and by the Comisión Nacional de Energía Atómica (Argentina). We are grateful to Dr P. Scacchi for performing the radioimmunoassay and to Prof. C. J. Gómez for the opportunity to perform this work.     

Butanol extracts from myelin fragments. III. SDS-urea gel electrophoretic studies

Summary The butanol extracts from myelin fragments showing 5-HT binding capacity were studied by SDS-urea gel electrophoresis. 5 main bands were observed and their molecular weights were determined by the method of Ferguson relationship, and revealed that these extracts contained proteolipid protein, DM-20 and basic proteins. Furthermore, the reconstituted fraction with crude basic proteins and lipids showed the saturable binding capacity for C¹⁴·5-HT.Acknowledgment. We thank Prof. T. Iwamoto for his encouragement during the course of this study.     

Demonstration of the structural connections of the longitudinal muscle cells and circular muscle cells,and interconnections between the two,in the alimentary canal of an oligochaete,Branchiura sowerbyi B.

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.     

On the inhibitory action of endosperm on germination ofCercis siliquastrum seeds

Summary The endosperm inhibits the growth of embryos isolated fromCercis siliquastrum seeds. The inhibitory activity is present in autoclaved homogenates as well as in homogenates remaining after an extraction with chloroform or isobutanol.Acknowledgment. The authors wish to thank Prof. E. Marré, Milan University, for his help in preparation of this paper.     

Effect of cyproterone acetate on the testis and epididymis of the lizard,Psammophilus dorsalis (Gray)

Summary The effect of cyproterone acetate (CPA) on the testis and epididymis of the lizard,Psammophilus dorsalis has been studied. Treatment with CPA affects spermatogenesis and steroid metabolism in the testis. It also causes regression of the epididymis and a decrease in steroidogenic enzyme activity.Acknowledgments. We wish to thank Prof. M.R. Rajasekarasetty for his encouragement, Dr K.V. Rao, Nagpur, for a generous gift of cyproterone acetate, Dr V.B. Nadkarni, Dharwar, for permitting the use of his cryostat, Sri B.M. Sekharappa for his technical assistance and UGC, New Delhi for their financial help to one of us (GRS).     

A blocked mutant ofClaviceps purpurea accumulating chanoclavine-I-aldehyde

Summary An alkaloid-blocked mutant ofClaviceps purpurea was isolated from a strain which produces ergotoxine alkaloids. The mutant accumulates chanoclavine-I and the corresponding aldehyde. It lacks the ability to form tetracyclic ergolines.Dedicated to Prof. Dr Dr h.c. K. Mothes on the occasion of his eightieth birthday.     

Preformed azulene pigments ofLactarius indigo (Schw.) Fries (Russulaceae,Basidiomycetes)

Summary The structure of a new naturally-occurring azulene, 1-stearoyloxymethylene-4-methyl-7-isopropenylazulene, obtained from an acetone extract of the blue mushroomLactarius indigo, has been determined by chemical and spectral methods.This paper is dedicated to Prof. André Dreiding, Zürich, on the occasion of his 60th birthday.