Trypsin activity in the midgut ofSarcophaga ruficornis andMusca domestica (Diptera: Insecta)

Summary The pH and temperature for the optimum activity of trypsin from the midgut ofSarcophaga ruficornis andMusca domestica was 7.5 and 8.0 respectively and 50°C. The enzymic activity increased with the increase in incubation period and enzyme concentration.Thanks are due to Prof.R. Rakshpal for guidance.     

A study on the parameters of digestion inPeriplaneta americana L

Summary An attempt was made to provide evidence for the regulatory mechanism for digestion inPeriplaneta americana by studying possible correlations between digestive enzymes, taking midgut protease activity into considerationI wish to acknowledge Prof. J. Bahadur, Jiwaji University, Gwalior, India, for his supervision, criticism and encouragement during the course of this study. Award of Junior Research Fellowship by C.S.I.R., New Delhi is also thankfully acknowledged.     

Amino acid requirements of the bugDysdercus similis freeman (hemiptera: Heteroptera)

Summary The amino acid requirements for moulting, growth and development ofDysdercus similis have been investigated. The insects could not moult and reach maturity when given 10 essential amino acids only. However, if these were supplemented either with glutamic acid, glycine or aspartic acid growth and moulting was found to be normal.Dysdercus has an unusual synthetic mechanism for converting tyrosine into phenylalanine.The author is grateful to Prof.R. S. Saini for his guidance, critical discussions and encouragement.     

Immunocytochemical reaction of a haemocyanin antibody in the midgut gland ofNautilus (Cephalopoda,Tetrabranchiata)

The branchial gland of the dibranchiate cephalopods is described as the site of haemocyanin synthesis. Because there is no equivalent to this organ in tetrabranchiate cephalopods the localization of haemocyanin synthesis remained unknown for a long time. In this study we could confirm the conclusions from prelimnary investigations concerning the copper content of the midgut gland ofNautilus, which gave the first indications for a possible localization of haemocyanin synthesis in this organ. We developed a polyclonal antibody againstNautilus haemocyanin, tested its specificity, and used it on ultra-thin sections of the tissue of the midgut gland. It could be shown that there is a clear imunogold precipitation only on the triangular basal cells in the terminal alveoli. All the other types of cell in this organ were free of any immunoreactivity. It can be supposed that the triangular basal cells in the terminal alveoli of the midgut gland are the sites of haemocyanin synthesis inNautilus.     

Giffordene, 2Z, 4Z, 6E, 8Z-undecatetraene,is the odoriferous principle of the marine brown algaGiffordia mitchellae

Summary Giffordene, 2Z, 4Z, 6E, 8Z-undecatetraene, and five stereoisomers are new odoriferous C₁₁H₁₆-hydrocarbons from the marine brown algaGiffordia mitchellae. Their isolation and identification is described.Acknowledgments. We thank Prof. G. Ohloff for kindly providing us with synthetic 1,3,5,7-undecatetraenes and Prof. P. Schreier for GC/FTIR-analyses.     

Presence of intrachromatidic bands in mitotic chromosomes ofTriturus marmoratus (Amphibia: Caudata)

Summary The C-banding technique has revealed the existence of single and double intrachromatidic bands in mitotic chromosomes ofTriturus marmoratus. The presence of the bands is discussed on the basis of the helical coil model versus the radial loop model, which assumes a different packing of the DNA fiber.We are very indebted to Prof. C. García de la Vega for his indispensable help, to Prof. Dr J. Martín for his comments and to M. Herrero for his support.     

Chromosomes of the squirrelFunambulus palmarum bellaricus Wroughton

Summary The chromosome complement ofFunambulus palmarum bellaricus Wroughton (Mammalia-Rodentia-Sciuridae) has been studied for the first time, and the diploid number established to be 54, in contrast to the subspeciesF. p. palmarum which has 2n=46 chromosomes. The known karyotypes within the genusFunambulus are compared. We thank Prof. G. T. Tonapi for providing the laboratory facilities and the Zoological Survey of India, Western Regional Station, Pune for identifying the specimens.     

C-band positive W chromosome in the female Indian frog

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.     

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.     

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.     

The occurrence of arachidonic acid in the venom duct of the marine snailConus textile

Summary A crude extract of the venom of the marine snailConus textile Linné caused a powerful contraction in the guinea-pig isolated ileum. The extract of the venom has been fractionated, and the fractions monitored by the contractile effect. Arachidonic acid was shown to be present as an active substance.Acknowledgment. We are grateful to Mr Z. Nagahama of Okinawa island for suppling specimens ofC. textile and to Dr T. Higashijima and Prof. T. Miyazawa (Department of Biophysics and Biochemistry, Tokyo University) for 270 MHz¹H-NMR-measurements.     

Buffalo α S1-casein; its terminal residues and amino acid composition

Summary BuffaloaS₁-casein was treated with carboxypeptidase-A to determine the C-terminal amino acid residue, which was — leucine-tryptophan. The Sakaguchi reagent was used to confirm arginine as the N-terminal amino acid. The colored p-phenylazophenyl thiohydantions of tryptophan and arginine released from C- and N-terminals respectively were quantitatively estimated and from this molecular weights of buffaloaS₁ casein were calculated and found to be 26,300 and 26,100 respectively.Acknowledgment. We are thankful to Prof. B. K. Bachhawat, Indian Institute of Chemical Biology, for encouragement. We also thank Prof. S. K. Mukherjee, Bose Institute, for amino acid analysis. Part of this work was completed when the authors were at the University of Kalyani, West Bengal.     

Occurrence of carotid labyrinth in the catfish group of teleost fishes

Summary A structure similar in topography and morphology to the carotid labyrinth of amphibians has been found in 4 catfishes, namely,Clarias batrachus, Heteropneustes fossilis, Rita rita andMystus seenghala. The present finding of the presence of the carotid labyrinth in fishes is the first report, and the results are discussed in the light of the amphibious habit of these catfishes.We are grateful to Prof. U.S. Srivastava for providing laboratory facilities and for encouragement. The work was financially supported by the S.C.S.T., U.P. which is thankfully acknowledged.     

Ageing of the erythrocyte. XVI. Free amino acid content

Summary The concentrations of some free amino acids, especially glycine, histidine, isoleucine, methionine, phenylalanine, serine and tyrosine decrease considerably during the intravascular ageing of bovine erythrocytes. They seem to provide as sensitive an indication of red cell age as creatine does.Stimulating discussions with Prof. W. Leyko and the experimental help of Mrs A. Rogala, are greatly acknowledged.     

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.     

Cyclic AMP during development and ageing of the insectCeratitis capitata

Summary Cyclic AMP was determined during the development of the dipteraCeratitis capitata. The concentration of the nucleotide reaches a peak at apolysis with a sharp decline in the pharate adult stage. A gradual increase takes place through the longevity of adult stage reaching a maximum plateau at the end of life.We are indebted to Prof.A. M. Municio for advice and encouragement and Mr.V. G. Corces for technical assistance.     

Endophenotype of mysore (south india) population of the black rat (Rattus rattus L.)

Résumé Contribution à l'étude du polymorphism chromosomique chez le rat noirRattus rattus L.

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We are grateful to Prof.M. R. Rajasekarasetty for helpful suggestions and one of us (KLSP) to the University Grants Commission, New Delhi, India, for awarding a Research scholarship.     

The site of synthesis of hemocyanin in the crayfish,Astacus leptodactylus

Summary The in vitro incorporation of³⁵S-methionine into hemocyanin was tested in the crayfish,Astacus leptodactylus. All organs assayed (hemocytes, heart, hypodermis, midgut gland, muscle and stomach) were able to synthesize proteins under our experimental conditions, but only midgut gland (=hepatopancreas) incorporated labeled methionine into a protein which was precipitated by an antibody againstAstacus hemocyanin, and which comigrated with authentic hemocyanin on SDS gels.     

Larvale und imaginale Mitteldarmchromosomen vonDrosophila repleta

Summary In certain tissues ofD. repleta-flies, it is possible to observe the interphase chromosomes that are either of larval origin or that occur in imaginal tissues. The imaginal interphase chromosomes from the midgut are similar to the small larval midgut chromosomes in the early phases of their development.     

On the stability of bilirubin

Riassunto Gli autori hanno studiato l'azione della luce sulla stabilità della bilirubina in soluzione alcalina e in soluzione cloroformica. Viene proposto, in via generate, un meccanismo del primo ordine per la trasformazione della bilirubina in pigmenti verdinoidi, sia per le soluzioni irradiate, sia per quelle conservate al buio.

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Research carried out with CNR financial support. A report on this investigation, with more detailed experimental data, has been published in Acta medica romana (Annali della Facoltà di Medicina e Chirurgia dell'Università Cattolica del Sacro Cuore in Roma)2, 192 (1964).

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We are indebted to Prof. P.Fasella, University of Rome, and to Prof. A.Vaciago, Sacred Heart Catholic University Medical School, for their helpful suggestions and constructive criticisms. One of us (I. W. de E.) is also grateful to Prof. Ing. W. S.Hill, University of Montevideo, for his suggestion to her to investigate bilirubin spectroscopically.