Über den Einfluss der Königin auf die arbeiterinnen Fertilität im Ameisenstaat

Zusammenfassung Es wird die Eiablage weiselloser vonLeptothorax tuberum unifasciatus und einiger anderer Arten untersucht. Die weisellosen legen mehr Eier als die Königin in einer gleichstarken-Gruppe. Entweiselte brauchen einen gewissen Zeitraum (Inkubationszeit), bis sie fertil werden. Aus diesen Befunden geht hervor, dass die in natürlich zusammengesetzten Völkern steril sind. Der -Duft allein kann die-Fertilitä nicht hemmen. Von der abgetrennte legen keine Eier, wenn ihnen täglich aus der Umgebung der zugesetzt werden. Zur Erklärung dieser Vorgänge wird die Hypothese der profertilen Stoffe entwickelt und dem -Duft eine wesentliche Rolle als Auslöser für ihre Weitergabe zugeschrieben.Herrn Prof. Dr.K. Gösswald danke ich für Anregung und Förderung der Untersuchungen.     

The secant condition for instability in biochemical feedback control—I. The role of cooperativity and saturability

This paper concerns oscillations arising in a sequence of biochemical reactions      

Leptothorax (Mychothorax) muscorum Nylander undLeptothorax (M.) gredleri Mayr zwei gute Arten

Zusammenfassung Körpergrösse, Epinotaldornlänge, Kopulationsorgane der , Form des Clypeus und Färbung von und sind beiLeptothorax (Mychothorax) muscorum Nyl. undL. (M.) gredleri Mayr so verschieden, dass beide Arten eindeutig zu unterscheiden sind. In der Umgebung von Würzburg kommen beide Arten eng nebeneinander vor und schwärmen zur gleichen Zeit ohne sich zu kreuzen. Sie sollten daher als gute Arten betrachtet werden.

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Summary Length of body and epinotal spines, male genitalia, structure of clypeus and colour of and ofLeptothorax (Mychothorax) muscorum Nyl. andL. (M.) gredleri Mayr are as much different that the two species are clearly to distinguish. Around Würzburg both species are found closely together and swarm simultaneously without crossbreeding. Therefore they should be considered as valable species.

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Résumé La longueur du corps et des épines épinotales, les génitalia mâles, la façon du clypeus et la coloration de et deLeptothorax (Mychothorax) muscorum Nyl. etL. (M.) gredleri Mayr sont assez différentes que l'on peut distinguer les deux espèces nettement. Autour de Würzburg les deux espèces sont trouvées souvent ensemble; l'essaimage a lieu au même temps sans croisement. C'est pourquoi elles doivent être considérées comme des espèces valables.

     

Callionymus leucopoecilus,a new dragonet (Callionymidae) from the Yellow Sea

Callionymus leucopoecilus, a new species of dragonet from the Yellow Sea, is described and illustrated. The new species is characterized by 4 spines in the first dorsal fin, 9 rays each in the second dorsal and anal fins, ii, 5, ii principal caudal fin rays, a preopercular spine formula of      

Contribution on the diagnosis ofStaphylococcus aureus rosenbach

Возможность трансформации прогестерона, стероида ?S? (11-дезокси-17-гидроксикортикостерон), дегидроэпиандростерона и

     

Morphologie et comportement des fourmis lestobiotiques du genreEpixenus Emery

Résumé Les petides Fourmis du genreEpixenus, considérées comme parasites et sans parEmery (1922), sont en réalité souvent pourvues nombreuses et capables de nicher indépendamment. C'est le cas d'E. algiricus Bernard, décrit ci-dessus, qui peut avoir plus de 1 000 ouvrières et 8 reines. Le quart seulement des nids observés aux environs d'Alger semblaient associés à d'autres genres, surtoutMessor etCamponotus. LesEpixenus (4 espèces certaines) sont surtout insectivores et assez proches desMonomorium, avec toutefois des larves et des reines plus primitives.

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Summary The small Ants of the genusEpixenus, described byEmery (1908) as probably parasitic and without workers, are in fact often with numerous workers and have independent nests. The best known isE. algiricus Bernard, described here, having sometimes more than 1 000 and 8 queens. Only one fourth of the nests observed in the neighbourhood of Algiers seems to be associated with other genera, chieflyMessor andCamponotus. Epixenus (4 sure species) are mainly insectivorous and nearMonomorium, with, however, queens and larvae more primitives.

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Laboratoire de Zoologie. Faculté des Sciences d'Alger.     

Enzyme kinetics of a highly purified mitochondrial creatine kinase in comparison with cytosolic forms

Summary Mitochondrial creatine kinase (CK) purified from canine myocardium showed a single protein band on SDS-PAGE and was free of MMCK. Its amino acid composition was different than MMCK or BBCK and did not react to antiserum to MMCK or BBCK. Using purified mitochondrial, MM and BBCK, the velocity of reaction (V) was estimated for creatine phosphate (CP), creatine (C), adenosine triphosphate (ATP) and adenosine diphosphate (ADP) over a wide range of concentrations including those at V_max. The values for K_m (mM/L) derived from Lineweaver-Burke plots are shown: The affinity of mitochondrial CK for C is much greater than MMCK which is compatible with the energy shuttle hypothesis, namely ATP is converted by mitochondrial CK to CP, and then diffuses to the myofibril for conversion to ATP for utilization.     

Proline peptide isomerization and protein folding

The unfolding-refolding of proteins is a cooperative process and, as judged by equilibrium properties, occurs in one step involving the native,N, and the unfoldedU, conformational states. Kinetic studies have shown that the denatured protein exists as a mixture of slow-(U)_Sand fast-(U)_Frefolding forms produced by proline peptidecis-trans isomerization. Proline residues inU _Fare in the same configuration as in the native protein while they are in non-native configuration inU _S. For protein folding to occur quicklyU _Smust be converted intoU _F. The fact that the equilibrium and kinetic properties of are the same as those found for prolinecis-trans isomerization taken together with the absence of slow phase in the kinetics of refolding of a protein devoid of proline, support this view. However, the absence of a linear correlation between half-time of reactivation of denatured enzymes and their proline-contents, as well as the dissimilarities in the kinetic properties of in unfolding and refolding experiments are not consistent with the model. Conformational energy calculation and experimental results on refolding of proteins suggest that some proline residues are non-essential. They will not block protein folding even in wrong isomeric form. The native-like folded structure with incorrect proline isomers will serve as intermediate state(s) in which these prolines will more readily isomerize to the correct isomeric form. The picture becomes more complex when one considers the consequence ofcis-trans isomerism of non-proline residues on protein folding.     

Human population growth: Local dynamics-global effects

This communication presents a very simple model for the global growth of the human population. It is shown that the solution of the simple equation describes the experimental data remarkably well. This equation is derived by introducing a new, local concept: the individual quality of life and by assuming that human breeding strategy consists in keeping this quantity constant through the ages. However the model should be enlarged with a saturation mechanism if future growth is to be described.     

Leaf surface fungi of Oryza sativa Linn

An investigation into the fungal population of phyllosphere and phylloplane regions of green and newly detached yellow leaves ofOryza sativa was undertaken. The dominant fungal species in the phyllosphere-regions of green and yellow leaves mostly differed. The following trend was exhibited in the appearance of the dominant species in the phyllosphere at different stages of plant growth. No dominant form was isolated from phyiloplane region of green leaves.Phoma sp. was continuously isolated as dominant from the phylloplane of yellow leaves.A number of species, though present abundantly on the phyllosphere regions of green and yellow leaves, were not obtained from their respective phylloplane regions.     

A quantum model for controlled enzymic reactions

A quantum model for the general enzymic reaction,E+S ⇌ ES → P, is presented, starting with the assumptions that any chemical substanceS, which may be a substrate for a particularE _(S)-enzyme is a microphysical system and any enzymeE-molecule, capable of interacting with anS-substrate is a “measuring system” which will “measure” one or more of theS-observables. According to the above assumptions a stochastic model of the reaction is constructed and a computer simulation of the steady state performed. The results thus obtained predicted fluctuations in the enzymic reaction rate, function of the substrate “perturbation”. On an experimental basis it is demonstrated that the irradiation of an enzymic substrate with low energies results in the inducement of a dose-dependent oscillatory behavior in the corresponding enzymic reaction rate. In the reaction type, the oscillations thus induced in theE-activity by the corresponding substrates are out-of-phase, realizing a biochemical discriminating net. Likewise, in an reaction type, the oscillations induced by the irradiatedS-substrate in the activities of the respective enzyme, realize a biochemical switching net.     

Ueber die Einwirkung von Begiftungen mit Neuzeitlichen Insektiziden auf Soziale Verhaltensweisen von Ameisen

C.—Zusammenfassung der Ergebnisse In ausgedehnten Versuchsreihen wurden vonLasius niger L., die durch Begiftung mit den Kontaktinsektiziden DDT, HCH, E 605 und Chlordan verschieden stark geschädigt waren, auf ihre Fähigkeit hin überprüft, einige für ihr soziales Verhalten typische Tätigkeiten noch richtig auszuführen. Die Störungen bei der Ausführung des Puppensammelns, bei der Fütterung und im Kampfverhalten lassen sich neben allgemeinen Lähmungserscheinungen vor allem auf Ausfallserscheinungen in der Mandibelfunktion zurückführen, die in einer für jedes Insektizid charakteristischen Weise eintreten. Da trotz funktioneller Störungen das jeweils entsprechende Appetenzverhalten erkennbar ist, kann man annehmen, dass anfänglich durch die Vergiftung keine zentralen Ausfallserscheinungen bewirkt werden. Wenn leicht begiftete, die kein Futter mehr annehmen, mit gesunden Futterträgerinnen zûsammengebracht werden, zeigt sich auf Seiten der Futterträgerinnen ein ganz eindeutiges Anbietungsverhalten, das sonst wegen der sofort einsetzenden Fütterung nur schwer zu beobachten ist. Kämpfe zwischen Nestgenossen als Folge der durch die Begiftung gesteigerten Erregbarkeit wurden unter der Einwirkung der appl. Gifte beiL. niger nicht beobachtet. Eine Uebertragung der angewendten Insektizide durch Kontakt zwischen begifteten und unbegifteten Tieren findet leicht statt.

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Summary In extend series of experiments workers ofLasius niger L., poisoned in different stages with the insecticides DDT, HCH, E 605f (Parathion) and Chlordane, were tested if they were still able for doing some works, typical for their social behaviour. The irregular working of ants collectingpupæ, feeding themselves and fighting can be explained above all by changements of the function of the mandibules. Such changements appeare in a manner, typical for each insecticid. Indepedent of the functional changements can be seen an appetence correspondenting with the behaviour. Therefore we can conclude, that primarily no changements of the central functions are effected by the examinated insecticides. Because the hungry but poisoned ants don't eat, the food carring workers offer the food in a typical manner. It's difficult to observe this behaviour in the norm for the workers feed directly themselves. Fightings between poisoned ants of the same colony as a consequence of the higher excitability could not been observed byL. niger. The examinated insecticides are easily transfered by contact between poisoned and unpoisoned ants.

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Résumé Dans des séries étendues d'expériences, des ouvrières deLasius niger L. différemment et fortement intoxiquées par les insecticides DDT, HCH, E 605f (Parathion) et Chlordane, furent éprouvées pour savoir si elles étaient encore capables de faire des actions sociales. Il est possible d'expliquer les dérangements chez les Fourmis recueillant despupæ, donnant le fourrage et combattant par des changements de la fonction des mandibules. Ces changements arrivent dans une manière typique pour chaque insecticide. Parce que l'appétence correspondante est reconnaissable, on peut conclure que ne sont pas effectués de changements des fonctions centrales par l'intoxication commençante. Parce que les ouvrières facilement intoxiquées n'acceptent plus de fourrage, les fourrageurs sains offrent le fourrage avec une manière très typique. Il est très difficile d'observer cette manière dans le cas normal, car les Fourmis se donnent à manger tout de suite. Des combats ne furent pas observés entre les compagnons d'un nid chez lesL. niger. Les insecticides examinés sont transmis facilement par le contact entre les Fourmis intoxiquées et leurs compagnons sains.

     

The structure of 5a,6–anhydrotetracycline and its Mg2+ complexes in aqueous solution

Semiempirical molecular orbital theory has been used for a systematic scan of the binding positions for a Mg²⁺ ion with 5a,6–anhydrotetracycline taking both conformational flexibility and possible different tautomeric forms into account. The magnesium ion has been calculated alone and with four or five complexed water molecules in order to simulate the experimental situation more closely. The results are analyzed by comparing the behavior of the title compound with that of tetracycline itself and possible causes for the stronger induction of the Tetracycline Receptor (TetR) by 5a,6–anhydrotetracycline than by tetracycline are considered. Energetically favored 3D -structure of the zwitteranionic 5a,6-anhydrotetracycline magnesium complex in solution Electronic Supplementary Material Supplementary material is available for this article at     

Effects of root temperature on uptake of nitrate and ammonium ions by barley grown in flowing-solution culture

Summary Barley plants (Hordeum vulgare L.) grown from seed for 28 days in flowing solution culture were subjected to different root temperatures (3, 5, 7, 9, 11, 13, 17, 25°C) for 14 days with a common air temperature of 25/15°C (day/night). Uptake of NH₄ and NO₃ ions was monitored separately and continuously from solutions maintained at 10 M NH₄NO₃ and pH 6.0. Effects of root temperature on unit absorption rate , flux and inflow were compared. After 5 days , and increased with temperature over the range 3–11°C for NH₄ ions and over the range 3–13°C for NO₃ ions, with little change for either ion above these temperatures. Q₁₀ temperature coefficients for NH₄ ions (3–13°C) were 1.9, 1.7 and 1.6 for , and respectively, the corresponding values for NO₃ ions being 5.0, 4.5 and 4.6. For both ions, , and changed with time as did their temperature dependence over the range 3–25°C, suggesting that rates of ontogenetic development and the extent of adaptation to temperature may have varied among treatments.     

Primary sequence dependence of conformation in oligomannose oligosaccharides

The oligomannose series of oligosaccharides from bovine thyroglobulin (BTG) and the variant surface glycoprotein (VSG) ofTrypanosoma brucei have been isolated and sequenced by¹H NMR. The structure of Man₉GlcNAc₂, the parent molecule of the series, is shown below. Structural isomerism occurs within this series through the removal of residues D1, D2, D3, and C. Using spin-spin coupling and chemical shift data the rotamer distributions about the dihedral angle ω for the Manα1-6Man\ and Manα1-6Manα linkages were determined for each member of the series. It is shown that the dihedral angle ω of the Manα1-6Man\ linkage exhibits low flexibility with a preference for the ω = 180° conformation when residue D2 is present and high flexibility when this residue is absent. Flexibility of ω for the Manα1-6Manα is largely independent of primary sequence and is intermediate between the two Manoα1-6Man\ extremes, again with a preference for the ω = 180° conformation. There are, however, data which indicate that removal of residue D3 may confer additional flexibility upon the dihedral angle ω of the Manα1-6Manα linkage. Molecular graphics modelling, together with chemical and enzymatic modification studies, suggest that the origin of the observed primary sequence dependence of the Manα1-6Man\ linkage arises from steric factors. On the basis of these observations taken together with previous work, it is postulated that recognition of individual oligomannose conformations may play a role in the control of N-linked oligosaccharide biosynthesis. Offprint requests to: T W Rademacher     

Effects of common soil anions and pH on the uptake and accumulation of perchlorate in lettuce

A mechanistic understanding of perchlorate () entry into plants is important for establishing the human health risk associated with consumption of contaminated produce and for assessing the effectiveness of phytoremediation. To determine whether common soil anions affect uptake and accumulation in higher plants, a series of competition experiments using lettuce (Lactuca sativa L.) were conducted between (50 nM) and (4–12 mM), (1–10 mM), or Cl⁻ (5–15 mM) in hydroponic solution. The effects of (0–5 mM) and pH (5.5–7.5) on uptake were also examined. Increasing in solution significantly reduced the amount of taken up by green leaf, butter head, and crisphead lettuces. Sulfate and Cl⁻ had no significant effects on uptake in lettuce over the concentrations tested. Increasing pH significantly reduced the amount of taken up by crisphead and green leaf lettuces, whereas increasing significantly reduced uptake in butter head lettuce. The inhibition by across all lettuce genotypes suggests that may share an ion carrier with , and the decrease in uptake with increasing pH or provides macroscopic evidence for cotransport across the plasma membrane.     

Die systematischen Grundlagen der Waldameisenvermehrung in Deutschland

Résumé Les différences morphologiques entre les deFormica rufa L. et celles deF. polyctena f?rst. sont décrites. Les deux espèces sont distinguées par le nombre des poils. En outre les nids de chaque espèce ont une odeur spéciale. Les nids deF. rufa L. sont en partie monogynes et en partie polygynes, ceux deF. polyctena f?rst., le plus souvent polygynes. Jusqu'à présent on a multiplié les deux espèces ensemble. En se rencontrant, elles se combattent. L'auteur propose de multiplier désormais seulementF. polyctena f?rst, parce que cette espèce est plus souvent polygyne queF. rufa.

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Riassunto Le differenze morfologiche delle diFormica rufa L. eF. polyctena f?rst. sono descritte brevemente. Si possono separare le due specie per mezzo della pelosità del torace e della testa. Oltre a ci? tutte le due hanno un odore specifico. I nidi diFormica rufa L. sono in parte monogini e in parte poligini, quelli diFormica polyctena f?rst. sempre poligini. Finora le due specie sono state trapiantate insieme. Esse si combattono quando si incontrano. L'Autore propone di usare per i trapianti solamente laFormica polyctena f?rst. poichè questa specie è in Germania più abbondante dellaFormica rufa poligina.

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Die Arbeiten wurden mit Unterstützung der Deutschen Forschungsgemeinschaft durchgeführt.     

Three-dimensional structure of the catalytic domain of the yeast β-(1,3)-glucan transferase Gas1: a molecular modeling investigation

The three-dimensional (3D) structure of the catalytic domain of Gas1p, a protein belonging to the only family of β-(1,3)-glucan transferases so far identified in yeasts and some pathogenic fungi (family GH-72), has been predicted by combining results derived from threading methods, multiple sequence alignments and secondary-structure predictions. The 3D model has allowed the identification of several residues that are predicted to play a crucial role in structural integrity, substrate recognition and catalysis. In particular, the model of the catalytic domain can be useful for designing site-directed mutagenesis experiments and for developing inhibitors of Gas1p enzymatic activity. Figure Three-dimensional models of the Gas1p catalytic domain as predicted using as template 7A3H (PDB code) protein Electronic Supplementary Material Supplementary material is available for this article at     

Mycorrhizae are present in cycad roots

We describe the occurrence of arbuscular mycorrhizae in the roots ofZamia pumila andDioon edule. Seedlings were grown on native, unsterilized soil taken from local pinelands of south Florida, whereZ. pumila occurs naturally. Arbuscules, hyphae, hyphal coils, and vesicles occur in the parenchyma cells of the root cortex, especially the half of the cortex next to the stele. Hyphae of the arbuscular mycorrhizal fungi (AMF) occur mainly in longitudinal intercellular spaces and conform to theAcorus type. The finest, ultimate roots have AMF, but these roots are extremely brittle, detach with the slightest disturbance, and are usually lost when plants are uprooted from the ground. No AMF were found in the cortex of coralloid roots. Vovides (1991) previously reported that AMF occur onDioon edule and Ceratozamia mexicana, and we reconfirm this inD. edule. In this species, AMF appear to be mostly associated with the outer and to a lesser extent the inner cortex. However, roots of a potted plant of C.hildae growing in native soil lacked AMF. When grown on low phosphorus soils, legumes are known to require AMF in order for theirRhizobium nodules to fix nitrogen. Without AMF, the legumes are deficient in phosphorus, which inhibits nodule production and nitrogen fixation. It is probable that cycads, with their nitrogen-fixing coralloid roots containingNostoc, may also require AMF for successful nitrogen fixation when phosphorus is limiting.