A reinvestigation of the chemistry of the Dufours gland of the formicine ant,Anoplolepis custodiens

The components of individual Dufours glands excised fromAnoplolepis custodiens workers were analysed by GC-MS. In addition to then-alkanes andn-alkenes previously reported² in these glands, primary alcohols (C₁₉-C₂₂), secondary alcohols (C₂₀-C₂₃), 2-ketones (C₂₀-C₂₃) and possibly carboxylate ethyl esters (C₁₉ and C₂₁) were identified as components of these glands. It seems possible that these high-boiling compounds are used by the workers in laying trails on the hot sandy surfaces of their characteristic habitat and in lining of the inner walls of nests, but no standard compounds have been available to us for any behavioral studies.     

Endocytosis and inositol hexakisphosphate levels inras transformants ofDictyostelium discoideum amoebae

Summary Fluid-phase pinocytosis kinetics and lysosomal enzyme secretion parameters were measured inDictyostelium discoideum amoebae constructed from strain AX3 by transformation with a multicopy plasmid carrying either a normalras gene (ras-Gly12), a mutatedras gene (ras-Thr12) or by the vector carrying the geneticin resistance gene only (pDNEO2). It was found that the pinocytosis rate and extent as well as the lysosomal enzyme secretion were slightly different in the three strains. These changes, however, were related to minor modifications of the cellular volumes. The overall concentration of inositol hexakisphosphate was similar in the three strains.This work was supported in part by a grant from the Ligue Nationale Française contre le Cancer (n^o 880258) to MS, and by a grant from the Fonds National Suisse de la Recherche Scientifique (No. 3.623-087) to CR.     

Chromosomes of some Asian and South American squirrels (rodentia: Sciuridae)

Zusammenfassung Chromosomensätze verschiedener Sciurinae sind:Sciurus anomalus (2n=40),S. granatensis (2n=42),Callosciurus flavimanus (2n=40),Dremomys rufigenis (2n=38) undMenetes berdmorei (2n= 62). Ein Vergleich mit früher beschriebenen Sciurinae-Karyotypen ergibt als ursprünglich diploide Sätze 38–40, Spaltung, sowie Fusion zu grösseren und kleineren2n's führend.     

Karyotypic data for five species of anguid lizards

Zusammenfassung Die Chromosomensätze von 5 Eidechsenarten der Familie Aguidae, davon vier vom GenusGerrhonotus und eine vom GenusDiploglossus werden beschrieben.D. costatus ist 2n=36 mit 12 grossen metazentrischen Chromosomen und 24 Mikrochromosomen.G. multicarinatus ist 2n=48,G. paucicarinatus 2n=46 undG. coeruleus 2n=38. Diese 3 Arten haben einen identischen «nombre fondamentale» von 48 und alle haben 26 Mikrochromosomen.G. monticolus besitzt 2n=30. Die Anzahl der Mikrochromosomen ist auf 12 reduziert.     

Chromosomes of three Asian mammals:Meriones meridianus (Rodentia: Gerbillinae),Spermophilopsis leptodactylus (Rodentia: Sciuridae),Ochotona rufescens (Lagomorpha: Ochotonidae)

Zusammenfassung Chromosomenanalyse von 3 asiatischen Säugetieren:Meriones meridianus (2n=50),Ochotona rufescens (2n=60) undSpermiophilopsis lepto-dactylus (2n=38), Deren 2n's und Karyotypen wurden mit verwandten Formen ninsichtlich der Geschlechter und Gattungen verglichen und zur Klassifizierung diskutiert.     

New chromosome numbers in Australian Leptodactylidae (Amphibia,Salientia)

Summary Fra i Leptodactylidi Australiani,Cyclorana alboguttatus ha 2n=26 come le forme più generalizzate della famiglia, mentre alcune specie diLimnodynastes hanno 2n=22; specie di altri 5 generi hanno 2n=24. Fra questi ultimi, il problematicoRheobatrachus, completamente acquatico, possiede alcuni microcromosomi come i membri più primitivi dell'ordine.     

Purification and properties of glutamine synthetase I fromRhizobium sp. UMKL 20

Summary Glutamine synthetase I was purified fromRhizobium sp. UMKL 20 following polyethylene glycol precipitation. The enzyme had a subunit molecular weight of 58 kd. Apparent K_m values for ammonia and glutamate were 5.6 and 15.2 mM, respectively. Glutamine synthetase I activity was inhibited by several end products of glutamine metabolism. The purified enzyme was highly adenylylated (E _n ^– =8.5).Acknowledgment. I would like to thank Mr J. C. Lai for technical assistance. This work was carried out with the support of Vote F 153/79 from the University of Malaya.     

Chromosomal abnormalities in an anholocyclic biotype ofMyzus persicae (sulzer)

Résumé Le karyotype normal deMyzus persicae (Sulzer) provenant de diverses sources fut de 2n=12. Une forme anholocyclique verte de cette espèce possède un karyotype de 2n=13 ou 2n=14, avec 1 ou 2 autosomes non appariés. Une comparaison des dimensions relatives des chromosomes des karyotypes normaux et anormaux suggère que ces derniers dérivent des chromosomes par fragmentation.

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The work is sponsored by a British Science Research Council grant for research on variation inM. persicae, as part of the United Kingdom contribution to the International Biological Programme project on biological control of aphids.     

Der Mitosezyklus im diploiden und triploiden Wurzelmeristem vonScilla sibirica

Summary In meristematic root tip cells ofScilla sibirica (2n=12 and 3n=18) the following results were obtained with the aid of autoradiography: 1. The average duration of the mitotic cycle (2n=12) is 69.5 h. The G₁-phase lasts 36.5 h, the DNA synthetic phase 17.5 h, the G₂-phase 8 h and mitosis 7.5 h. 2. There are no marked differences in the lengths of the cell cycles nor in the duration of the various phases between diploid and triploid plants.     

On the question of American eels,Anguilla rostrata versus European eels,Anguilla anguilla

Zusammenfassung Der amerikanische AalAnguilla rostrata (2n=38; 20M+18A) gehört einer anderen Spezies an als der europäischeAnguilla anguilla (2n=38; 32M+6A).

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This work was supported in part by a grant No. CA 05138 from the National Cancer Institute, U.S. Public Health Service.     

Instar-specific defensive secretions of stink bugs (Heteroptera: Pentatomidae)

Defensive secretions (allomones) from first-instar nymphs of stink bugs in the subfamily Pentatominae contain (E)-4-oxo-2-decenal as a major constituent, whereas this compound is absent from later instars. In contrast, first instars ofEdessa meditabunda (Edessinae) produce allomones like those of later instars. The C₆ and C₈ (E)-4-oxo-2-alkenals are common, characteristic exocrine compounds of nymphal and adult Heteroptera, but (E)-4-oxo-2-decenal is previously unknown as a major natural product for which a biological role has yet to be established.     

I cromosomi di alcuniPipidae (Amphibia Salientia)

Summary The karyotype of the African PipidHymenochirus boettgeri (2n=24, all meta- or submetacentric chromosomes) is different from the one of the African PipidXenopus laevis (2n=36). The karyotype of the American PipidPipa (Protopipa)parva (2n=30, all acrocentric chromosomes) is very primitive and different from the karyotypes of the African Pipids and from that ofPipa pipa; the male meiotic chromosomes ofP. parva, usually with 1 procentric chiasma, show a clear difference from the male bivalents of the other Pipids, all with 2 terminal chiasmata.     

Chromosome polymorphism in the malayan house shrew,Suncus murinus (insectivora,soricidae)

Zusammenfassung 15 Exemplare vonSuncus murinus aus Kuala Lumpur und Petaling Jaya, Selangor (Malaysia) zeigten 3 Exemplare mit einer diploiden Zahl von 40, 9 weitere mit 2n=39 und 3 Exemplare mit 2n=38. Der Untrschied der Chromosomenzahl innerhalb einer Intrapopulation wird mit der Robertson'schen Translokation in Zusammenhang gebracht.     

A diploid population of the polyploid amphibianOdontophrynus americanus and an artificial intraspecific triploid hybrid

Resumen La ocurrencia de poliploidia ha sido relatada en anuros de la familia Ceratophrydidae incluyendo la especie tetraploideO. americanus (4n=44). En una área geográfica distinta, sin embargo, fue observada una población diploide deO. americanus (2n=22). Fueron obtenidos híbridos intraespecíficos triploides (3n=33) por cruzamiento de ejemplares diploides y tetraploides deO. americanus.     

Aberrant,canavanyl protein formation and the ability to tolerate or utilize L-canavanine

Summary L-Canavanine, 2-amino-4-(guanidinooxy)butyric acid, and L-arginine incorporation into de novo synthesized proteins was compared in six organisms. Utilizing L-[guanidinooxy¹⁴C]canavanine and L-[guanidino¹⁴C]arginine at substrate saturation, the canavanine to arginine incorporation ratio was determined in de, novo synthesized proteins.Caryedes brasiliensis andSternechus tuberculatus, canavanine utilizing insects;Canavalia ensiformis, a canavanine storing plant; and to a lesser extentHeliothis virescens, a canavanine resistant insect, failed to accumulate significant canavanyl proteins. By contrast,Manduca sexta, a canavanine-sensitive insect, andGlycine max, a canavanine free plant, readily incorporated canavanine into newly synthesized proteins. This study supports the contention that the incorporation of canavanine into proteins in place of arginine contributes significantly to canavanine's antimetabolic properties.     

RTA2 is involved in calcineurin-mediated azole resistance and sphingoid long-chain base release in Candida albicans

The calcineurin pathway has been reported to be essential for the development of azole resistance in Candida albicans. The depletion or ectopic over-expression of RTA2 increased or decreased susceptibility of C. albicans to azoles, respectively. CaCl₂- induced activation of the calcineurin pathway in wildtype C. albicans promoted resistance to azoles, while the Ca ²⁺ chelator (EGTA), calcineurin inhibitors (FK506 and cyclosporin A) and the deletion of RTA2 blocked the resistance-promoting effects of CaCl₂. Furthermore, we found that RTA2 was up-regulated in a calcineurin-dependent manner. The depletion of RTA2 also made the cell membrane of C. albicans liable to be destroyed by azoles and RTA2 over-expression attenuated the destroying effects. Finally, the disruption of RTA2 caused an increased accumulation of dihydrosphingosine (DHS), one of the two sphingolipid long-chain bases, by decreasing release of DHS. In conclusion, our findings suggest that RTA2 is involved in calcineurin-mediated azole resistance and sphingoid long-chain base release in C. albicans. Electronic supplementary material  The online version of this article (doi:) contains supplementary material, which is available to authorized users. Received 14 July 2008; received after revision 29 August 2008; accepted 16 September 2008     

Der Einfluss der Reizbedingungen auf den initialen Abfall der Cochlearpotentiale bei totaler Ischämie

Summary The rapid initial drop of the cochlear microphonic potential following compression of the aorta was studied in guinea pigs. The intensity of the stimulus, either continuous or intermittent, was without influence on the half-time of amplitude (t/2=52±7 s;n=18). From this it is concluded that the metabolism of the generator responsible for the cochlear microphonic is unaffected by the type or intensity of stimulation. The lower resistance of the neural action potential to ischemia was confirmed (t/2=18±2 s;n=5).     

A new 9,11-secosterol,stellettasterol from a marine spongeStelletta sp

A new 9,11-secosteroid, stellettasterol (1) was isolated from a Japanese marine sponge,Stelletta sp.; its structure was determined by spectroscopic analysis. All NMR signals of1 were unambiguously assigned by application of various 2D NMR techniques. Stellettasterol exhibited antifungal activity againstMortieralla ramannianus.Part 62 of the Bioactive Marine Metabolites series. Part 61: Fusetani, N., Takahashi, M., and Matsunaga, S., Tetrahedron, in press.     

Biomedicine and diseases: the Klippel-Trenaunay syndrome, vascular anomalies and vascular morphogenesis

Vascular morphogenesis is a vital process for embryonic development, normal physiologic conditions (e.g. wound healing) and pathological processes (e.g. atherosclerosis, cancer). Genetic studies of vascular anomalies have led to identification of critical genes involved in vascular morphogenesis. A susceptibility gene, VG5Q (formally named AGGF1), was cloned for Klippel-Trenaunay syndrome (KTS). AGGF1 encodes a potent angiogenic factor, and KTS-associated mutations enhance angiogenic activity of AGGF1, defining ‘increased angiogenesis’ as one molecular mechanism for the pathogenesis of KTS. Similar studies have identified other genes involved in vascular anomalies as important genes for vascular morphogenesis, including TIE2, VEGFR-3, RASA1, KRIT1, MGC4607, PDCD10, glomulin, FOXC2, NEMO, SOX18, ENG, ACVRLK1, MADH4, NDP, TIMP3, Notch3, COL3A1 and PTEN. Future studies of vascular anomaly genes will provide insights into the molecular mechanisms for vascular morphogenesis, and may lead to the development of therapeutic strategies for treating these and other angiogenesis-related diseases, including coronary artery disease and cancer.Received 24 November 2004; received after revision 21 January 2005; accepted 2 March 2005     

Karyotype in two himalayan species of polygonatum

Zusammenfassung Die Chromosomenzahl und der Karyotypus vonPolygonatum verticillatum Allioni (2n = 30, 64) undP. cirrifolium Royle (2n = 38), die im Himalaya vorkommen, wurden mit früher untersuchten europäischen Formen verglichen. Die beobachteten Unterschiede lassen sich durch die Annahme erklären, dass die europäischen Formen aus den Himalaya-Formen durch den Vorgang der Chromosomenverminderung und Veränderungen des Karyotypus hervorgingen.