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.     

A new neurosecretory system in fish,located in the gill region

Summary A peculiar neurosecretory system is reported in 6 teleost species;Clarias batrachus, Heteropneustes fossilis, Mystus seenghala, Ompak pabda, Glassogobius giuris andNotopterus notopterus. It is located in the gill region close to the pseudobranch or to the carotid labyrinth. The neurosecretory cells have been identified using stains specific for neurosecretion. The results are discussed in the light of the association of the neurosecretory system with the pseudobranch or the carotid labyrinth, and the airbreathing habit of these fishes.We are grateful to Prof. U.S. Srivastava for providing laboratory facilities and for encouragement. The work was financially supported by U.G.C. Research Project grant awarded to C.B.L.S., which is thankfully acknowledged. Thanks are due to M. Seal and Amarlata for technical help rendered.     

Y chromosome in the sibling speciesAnopheles atroparvus (van Thiel, 1927) andA. labranchiae (Falleroni, 1926) (Diptera: Culicidae): Differential behaviour of the short arm after acid-alkaline treatment and Coriphosphine-O staining

Summary An acid-alkaline treatment followed by Coriphosphine-O staining was used for detecting chromosomal differences between the 2 sibling speciesAnopheles atroparvus (van Thiel) andA. labranchiae (Falleroni) (Diptera: Culicidae). The short arm of the Y chromosome was found to stain differently in the 2 species.The authors wish to thank the entomologist C. Contini for collecting and classifyingA. labranchiae larvae and Prof. U. Bianchi and Prof. U. Laudani for helpful discussions and suggestions on the subject.     

RNA editing in plant organelles: machinery, physiological function and evolution

In plants, RNA editing is a process for converting a specific nucleotide of RNA from C to U and less frequently from U to C in mitochondria and plastids. To specify the site of editing, the cis-element adjacent to the editing site functions as a binding site for the trans-acting factor. Genetic approaches using Arabidopsis thaliana have clarified that a member of the protein family with pentatricopeptide repeat (PPR) motifs is essential for RNA editing to generate a translational initiation codon of the chloroplast ndhD gene. The PPR motif is a highly degenerate unit of 35 amino acids and appears as tandem repeats in proteins that are involved in RNA maturation steps in mitochondria and plastids. The Arabidopsis genome encodes approximately 450 members of the PPR family, some of which possibly function as trans-acting factors binding the cis-elements of the RNA editing sites to facilitate access of an unidentified RNA editing enzyme. Based on this breakthrough in the research on plant RNA editing, I would like to discuss the possible steps of co-evolution of RNA editing events and PPR proteins. Received 30 September 2005; received after revision 5 November 2005; accepted 28 November 2005     

Mitosis in the haemocytes ofSarcophaga ruficornis (diptera)

Summary Among the haemocytes ofSarcophaga ruficornis, only the prohaemocytes divide. Injection of phytohaemagglutinin-P induces 100% prohaemocytes to undergo mitosis but does not induce mitosis in other cells. Mitotic stages other than the prophase are apparently very short lived.Acknowledgment. We express our gratitude to the State Council of Scientific and Industrial Research, U.P. for the grant of financial assistance to U.S.S.     

Anatomical identification of the presumed electroreceptors of two air breathing catfishes,Clarias batrachus andHeteropneustes fossilis

Summary Histological preparations for light microscopy have revealed for the first time the structure of the electroreceptor ofClarias batrachus andHeteropneustes fossilis, the 2 Indian air-breathing catfishes. These sensory organs are found to resemble the ampullary organs of many weakly electric and nonelectric electroreceptive teleost.The work was in part supported by grant of SCST (U.P.) during the period 1974–76 which is acknowledged.     

Allantoinase in the marine polychaeteEudistylia vancouveri

Summary Allantoinase, an enzyme in the purine-urea cycle, was found inEudistylia vancouveri (Polychaeta). The enzyme had a pH optimum at 7.6 TheK _m was 0.012M allantoin, and the Arrhenius energy of activation was 12.6 to 14.6 kcal/mol.Supported by the U. S. National Science Foundation (Institutional Grant) and by the U. S. Environmental Protection Agency Grant No. T-900204 (WP-175). Publication No. 10 of the Laboratory of Biochemical Ecology; College of Fisheries Contribution No. 458. We thank Dr.Robert L. Fernald for generously making available to us the facilities of the Friday Harbor Laboratories, Friday Harbor, Washington.     

An evaluation of quarterly national institute forecasts

This paper examines the quarterly forecasts by the U.K. National Institute of Economic and Social Research of the rate of inflation and the change in real gross domestic product and its components for horizons of one to four quarters ahead in the U.K. The forecasts are tested to see if they satisfy three implications of the rational expectations hypothesis: unbiasedness, efficiency and consistency. Explicit consideration is given to the information set available when the forecasts are made. In general, the data are consistent with the rational expectations hypothesis and our results provide encouragement for the view that aggregate expectations will meet the ex post requirements of rationality.     

Asynchronous puffing in the foot pad chromosomes ofParasarcophaga

Summary The foot pad polytene chromosome IIIL ofParasarcophaga ruficornis andP. misera shows a heterozygous puff in the region 7B-C. InP. ruficornis the heterozygosity is manifested as a difference in the timing of puffing between the 2 homologues. The outer and inner dorsal cells of the same foot pad also reveal asynchrony in puffing at this locus.Acknowledgments. Thanks are due to Prof. U.S. Srivastava, Head, Dept. of Zoology, University of Allahabad for providing the laboratory facilities.     

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.     

The effect of sulfhydryl reagents upon the activity of 40S ribosomal subunits

Summary p-Chloromercuribenzoate inhibited the poly (U)-dependent binding of Phe-tRNA to the 40S ribosomal subunit but displayed no inhibitory effect on the binding of poly (U) to the ribosome. Other sulfhydryl reagents tested, likeN-ethylmaleimide and iodoacetamide, did not affect the binding of Phe-tRNA to the small ribosomal subunit.     

Cytogenetic studies with atrazine (2-chloro-4-ethyl-amino-6-isopropylamino-s-triazine) on plants

Zusammenfassung Untersuchungen anVicia faba- undHordeum-Wurzelspitzen sowie anSorghum-Pollenmutterzellen ergeben keine Hinweise für eine zytogenetische Wirksamkeit des Triazin-Herbizides Atrazin in Pflanzen.

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The authors are greatly indebted to Dr.U. Leuthold for his help in conducting the experiments. The excellent technical assistance of Mrs.J. Determeyer and MissD. Kempf is gratefully acknowledged.     

Structural diversity of trypsin from different mosquito species feeding on vertebrate blood

Summary Mosquito trypsin was purified using a combination of ion exchange and affinity chromatography with the ligand soybean trypsin inhibitor. ThreeAedes and threeAnopheles species were tested, all of which are specialized in the digestion of vertebrate blood. Amino-terminal sequences of HPLC-purified trypsins fromAedes aegypti andAnopheles quadrimaculatus revealed homologies of 30–40% with vertebrate and other invertebrate proteases previously identified as serine-proteases. The purified mosquito trypsins have molecular masses between 25 kDa and 36 kDa, as determined by denaturing polyacrylamide electrophoresis, and are heterogeneous in size and number in the various species. The number of SDS-bands varies between 3 and 6 inAedes and between 1 and 3 inAnopheles. The specific activities, determined with the substrate TAME, range from 240 U/mg inAedes aegypti to 1065 U/mg inAnopheles quadrimaculatus. All mosquito trypsins tested have acidic isoelectric points between pH 3.5 and pH 5.4. No alkaline proteases were detected. Polyclonal antisera againstAedes aegypti andAnopheles albimanus trypsin do not cross-react with bovine trypsin. Cross-reactivity of the two sera with trypsin from six mosquito species suggests the presence of at least 2 enzyme families.     

Einfluß von Penicillin auf die Wurzelkultur(Zea mays) Nachweis von β-Indolylessigsäure (Heteroauxin) im Handelspenicillin

Summary (1) Pure Penicillin Sodium G (150 U/cm³) gives no inhibition in the growth-rate ofmays-roots in sterile organe culture.(2) Commercial penicillin (Penicillin Sodium Squibb, 5 U/cm³) inhibits the growth-rate ofmays-roots in a fairly high degree, due to its content of indole acetic acid. We have been able to separate the substance from the yellow dyes of commercial penicillin by chromatographic adsorption and to identify it colorimetrically as indole acetic acid.     

Disparition de la 5-hydroxytryptamine dans les granulations des glandes de la peau deDiscoglossus pictus et deRana temporaria après injection de réserpine

Summary 30 min after an intraperitoneal injection of reserpine (5 or 10 mg/kg) in the frog (Rana temporaria) and in the toad (Discoglossus pictus), a substance which has the properties of 5-hydroxytryptamine (argentaffine reaction, azoreaction, indoreaction and fluorescence in U.V. after formaldehyde) disappears from the skin glands; the histochemical reactions are more positive again 1 1/2 to 2 h after the injection of reserpine.     

Vitellogenesis in the air breathing fish,Channa punctatus (Bloch)

Summary Two types of yolk develop in the oocyte ofChanna punctatus. The carbohydrate yolk, which develops from the material present in the ooplasm, breaks up for the use of the growing oocyte before ovulation takes place. The proteid yolk, developing from the extraoocytic material, finally crams the fully mature oocyte, perhaps to participate in the process of embryogenesis.Acknowledgments. The authors are grateful to Professor C.C. Das, for his encouragement and the laboratory facilities. The award of a U.G.C. junior fellowship to one of us (U.R.A.) by the Berhampur University is thankfully acknowledged.     

Somatic chromosomes of Indian burrowing toad,Uperodon globulosum (Gunther) (Anura; Amphibia)

Summary Somatic chromosome complements of the Indian burrowing toad,Uperodon globulosum, have been described for the first time. The 2n number is 26 (NF=52) in both the sexes. No heteromorphism in relation to sex chromosome pair has been recorded. Deviations from 2n number (2n=10–28) have been noticed in the cells of different specimens. The result has been compared withU. systoma.Acknowledgment. Sincere thanks are due to Prof. P. K. Ghosh, Hooghly Mohsin College and to Dr A. K. Roy of the same college for encouragement. Thanks are due to Mr Bipul Kumar Das for his help during collection of specimen.     

Quarterly liverpool model with current partial information: An exercise in forecasting

This paper applies an algorithm for the solution of partial current information in rational expectation models to the quarterly Liverpool macroeconomic model of the U.K. The algorithm is shown to produce marginally superior results in forecasts both in ex-post and ex-ante forecasts and can be viewed as an additional tool for the forecaster's kit-bag.     

In vitro metabolism of the trichothecene 4-monoacetoxyscirpenol by fungus- and non-fungus-feeding insects

Summary The metabolism of the trichothecene 4-monoacetoxyscirpenol by intact gut tissue was determined in the fungus-feeding Nitidulid,Carpophilus hemipterus (L.) and the non-fungus-feeding caterpillars, the fall armyworm,Spodoptera frugiperda (J. E. Smith) and the corn earworm,Heliothis zea (Boddie). The primary metabolite was the hydrolysis product scirpentriol. The amount of metabolism by theC. hemipterus larvae was ca 10 times that of the caterpillars on a per mg protein basis, suggesting metabolic adaptation for feeding on fungi that may contain mycotoxins.Acknowledgment. The authors wish to thank S. Taylor for technical assistance.The mention of firm names or trade products does not imply that they are endorsed or recommended by the U.S. Department of Agriculture over other firms or similar products not mentioned.     

Flavonoid profiles of certain species ofRhynchosia of the family Leguminosae (Fabaceae)

Summary A survey of seventy naturally occurring populations ofRhynchosia representing seven species of different subgenera revealed the occurrence of C-glycosides, O-glycosides, prenylated flavonoids and aglycones.Rhynchosia albiflora (R. cyanosperma) differs in gross morphological features and seed coat color and in its flavonoid composition from the other representative species ofRhynchosia.Acknowledgments. P. Ramachandraiah is grateful to U.G.C., New Delhi, for financial assistance.