The Mutation Spectrum of the CFTR Gene in Cystic Fibrosis Patients from Bashkortostan

Mutations of CFTR were studied in patients with cystic fibrosis (CF) from Bashkortostan. In total, 15 mutations were observed and 51% of all mutant alleles identified. The most diagnostically significant mutations were delF508 (33.8%), 394delTT (3.52%), CFTRdele2,3(21kb) (1.41%), R334W (1.41%), 3849 + 10kbC T (1.41%), and N1303K (1.41%). Mutations G542X, 2184insA, S1196X, and W1282X were each found in less than 1% patients. Five new mutations and two neutral substitutions were revealed. These were I488M (exon 10), 1811 + 12A C (intron 11), T663S (exon 13), I1226R (exon 19), 4005 + 9A C (intron 20), 2097A C (A655A, exon 13), and 3996G C (V1288V, exon 20). Bashkortostan was shown to differ in the CFTR mutation spectrum from other regions of Russia. The results will allow direct DNA diagnostics of CF in far more families. Molecular screening of probands" relatives will contribute to identification and medical genetic counseling of heterozygous carriers, which is essential for CF prevention.     

Corresponding Caricion bicolori-atrofuscae communities in western Greenland,northern Europe and the central European mountains

The alliance Caricion bicolori-atrofuscae comprises plant communities of more or less wet calcareous fens on shallow peat with a high base saturation, occurring in arctic as well as alpine, more seldom subalpine areas. The characteristic species are presented and compared with those from communities of the Caricion lavallianae growing in lowland and mountain sites of temperate and boreal calcareous fens.An abbreviated ecological characteristic is given and the contact communities of the different community complexes are pointed out. The regional floristic differences within the communities are shown, and the geographical distribution and regional frequency of the differentiated associations are given. The synsystematic ranks of three central European mountain to alpine associations are discussed in detail (Caricetum frigidae, Juncetum alpini, Equiseto-Typhetum minimi). They should be excluded from this alliance.Generally, the alpine phytocoenoses are more often invaded by species from neighbouring communities, presumably as an effect of competition in sites less favouring fen development in comparison to the oro-arctic and arctic sites, especially those with an oceanic to suboceanic climate.We conclude, that the observed floristic differences are mainly caused by historical processes and not by the different ecology of the sites in question. This must be taken into consideration when discussing the synsystematic delimitation and rank of the corresponding communities.Nomenclature follows: Lid (1974), Nyholm (1954–68). Acknowledgement. The authors are grateful to the Deutsche Forschungsgemeinschaft for travel grants since 1973 for their investigations in Scandinavia and Greenland.     

Mouse–Torpedo Chimeric α-Subunit Used to Probe Channel-Gating Determinants on the Nicotinic Acetylcholine Receptor Primary Sequence

1. To determine if structural domains are important for nicotinic acetylcholine receptor (nAChr) channel function, six mouse–Torpedo chimeric -subunits were constructed (Fig. 2) and coexpressed with Torpedo californica -, -, and -subunits in Xenopus laevis oocytes.2. nAChRs containing a chimeric -subunit were examined by voltage- and patch-clamp methods to determine their functional characteristics. Dose–response curves from voltage-clamped oocytes were used to estimate EC₅₀'s and Hill coefficients. Whole-cell currents were normalized against the -bungarotoxin (-BTX) binding sites to obtain normalized responses to acetylcholine (ACh). Open time constants at 4 M ACh were used to examine single-channel behavior.3. The EC₅₀ for ACh was modulated by the N-terminal half of the -subunit. When the Torpedo subunit sequence between position 1 and position 268 was replaced by mouse sequence, the EC₅₀ shifted toward the value for the wild-type mouse subunit. Replacement of either the 1–159 or the 160–268 positions of the Torpedo sequence with the mouse sequence lowered the EC₅₀. This suggests that at least two regions play a role in determining the EC₅₀.4. When the primary sequence (160–268) of the Torpedo -subunit was introduced in the mouse -subunit (T160–268), the expressed chimeric receptor was nonfunctional. The inverse chimera (M160–268) was functional and the open time constant and EC₅₀ were similar to those of mouse but the normalized response was characteristic of Torpedo.5. The normalized macroscopic response to ACh (300 M) of the chimera containing the mouse -subunit showed a ninefold increase relative to the Torpedo wild type. Receptors which contain the C terminal of the mouse -subunit also show an increase in the maximum normalized current. Receptors with the -subunit which contain the Torpedo C-terminal sequence have a lower normalized response.6. The combined results suggest that AChR channel function is modulated by structural determinants within the primary sequence. These structural domains might modulate channel function through specific allosteric interactions. The lack of response of the T160–268 chimera suggests that a critical interaction essential for the coupling of agonist binding and channel gating was disrupted. This result suggests that the interaction of structural domains within the nAChR primary structure are essential for channel function and that these intractions could be very specific within different nAChR species.     

Regulation of anaerobic respiratory pathways in Wolinella succinogenes by the presence of electron acceptors

In Wolinella succinogenes ATP synthesis and consequently bacterial growth can be driven by the reduction of either nitrate (E₀=+0.42 V), nitrite (E₀=+0.36 V), fumarate (E₀=+0.03 V) or sulphur (E₀=-0.27 V) with formate as the electron donor. Bacteria growing in the presence of nitrate and fumarate were found to reduce both acceptors simultaneously, while the reduction of both nitrate and fumarate is blocked during growth with sulphur. These observations were paralleled by the presence and absence of the corresponding bacterial reductase activities. Using a specific antiserum, fumarate reductase was shown to be present in bacteria grown with fumarate and nitrate, and to be nearly absent from bacteria grown in the presence of sulphur. The contents of polysulphide reductase, too, corresponded to the enzyme activities found in the bacteria. This suggests that the activities of anaerobic respiration are regulated at the biosynthetic level in W. succinogenes. Thus nitrate and fumarate reduction are repressed by the most electronegative acceptor of anacrobic respiration, sulphur. By contrast, in Escherichia coli a similar effect is exerted by the most electropositive acceptor, O₂. W. succinogenes also differs from E. coli in that fumarate reductase is not repressed by nitrate.Abbreviations BV benzyl viologen - DMN 2,3-dimethyl-1,4-naphthoquinone - DMSO dimethylsulfoxide - TMAO trimethylamine-N-oxide     

RexAB proteins of bacteriophage lambda enhance the effect of photolyase-dimer complexes on lacZ gene expression in Escherichia coli.

Summary Expression of the lacZ gene in Escherichia coli is inactivated by exposure to ultraviolet light (UV). Inactivation is exceptionally effective when cells contain amplified levels of DNA photolyase (which forms complexes with pyrimidine dimers in the absence of light for actual photoreversal) and a prophage. Without amplified photolyase, the prophage or both, inactivation rates are similar and much lower. UV-inactivation of lacZ gene expression in the presence of both amplified photolyase and is even more effective if cI857 is used in place of the wildtype prophage but is wholly unexceptional if the prophage carries defects in the genes rexA or rexB. When Rex AB proteins are provided by expression from a plasmid and the cell also contains amplified photolyase, exceptional inactivation rates again obtain; in fact inactivation is most effective under these conditions. The data are considered to reveal a role for Rex AB proteins, which mediate superinfection exclusion, in the exceptional inactivation of gene expression by photolyase bound to pyrimidine dimers in DNA. Photolyase-dimer complexes may mimic the structure of certain complexes that arise during phage development and thus influence Rex A and/or B proteins, thereby shutting down cell metabolism.     

In vitro pollen selection in Brassica napus L. for resistance to phytotoxic compounds from Alternaria brassicicola (Schw.) Wilts

Summary Pollen samples from Brassica napus cvs Arran and Herkules were incubated for 1 h in a germination medium or in a medium to which 20 mg ml^–1 of a toxic extract from Alternaria brassicicola had been added. The pollen samples were then used to pollinate cv Primor. A number of the plants, obtained from pollinations using pollen incubated in the toxic extract, produced pollen with a significantly increased ability to germinate in medium containing 10 mg ml^–1 of the extract, evidence that some selection for resistance to the toxic compounds produced by A. brassicicola had occurred. The potential application of in vitro pollen selection and conditions necessary for its success are discussed.     

Metabolic formation of dodecanedioic acid from n-dodecane by a mutant of Candida tropicalis

Summary These experiments studied the metabolic formation of a,-dodecanedioic acid using the mutant S 76 developed from the wild strain Candida tropicalis 1230 (capable of producing large amounts of a,-dodecanedioic acid).Our results show for the first time that 12-hydroxydodecanoic acid was excreted into the medium as a free acid.n-Dodecanol and n-dodecanoic acid were also detected in the n-dodecane medium. The mutant S 76 was able to produce a,-dodecanedioic acid using either n-dodecanol or dodecanoic acid as the sole carbon source. Quantitative cahnges in the concentrations of 12-hydroxy-dodecanoic acid and other intermediates were recorded during the formation of a,-dodecanedioic acid. S 76 was rapidly able to convert large amounts of 12-hydroxy-dodecanoic acid to a,-dodecanedioic acid.The formation of a,-dodecanedioic acid from n-dodecane via the sequence n-dodecanoln-dodecanoic acid 12-hydroxy-dodecanoic acid was confirmed.     

Role of trichomes in soybean resistance to cabbage looper, Trichoplusia ni

Role of leaf trichome density and length in Glycine max (L.) Merr. resistance to Trichoplusia ni (Hübner) was evaluated at different leaf positions on a relatively resistant soybean, plant introduction (PI) 227687, and a relatively susceptible cultivar, Davis. The uppermost (juvenile) leaf within both PI 227687 and Davis plants, which is densely covered with trichomes, was most resistant to T. ni larval feeding and survival. When these trichomes were shaven off, such leaves became as susceptible to T. ni larval feeding as unshaven TL3 and TL5 leaves (PI 227687) or all other unshaven leaves (Davis). Bioassays for antifeedants in ethyl acetate and hexane extractables from leaves at the different positions on PI 227687 and Davis plants showed that the resistance observed in the uppermost Davis leaf is attributable to trichomes (i.e., a morphological factor); whereas, in the uppermost PI 227687 leaf it involves both morphological (trichomes) and chemical factors, but the trichome parameter is dominant.

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Résumé L'influence de la densité et de la longueur des trichomes de Glycine max sur la résistance à Trichoplusia ni a été évaluée suivant la position des feuilles sur une lignée résistante (PI 227687) et sur un cultivar sensible (Davis).Les feuilles apicales (juvéniles) tant de PI 227687 que de Davis, recouvertes de trichomes denses, résistèrent mieux à l'alimentation larvaire et à la survie de T. ni.Quand ces trichomes étaient éliminés, ces feuilles ne résistaient pas plus à l'alimentation des larves de T. ni que les feuilles non rasées TL3 et TL5 de PI 227687 ou toutes les autres feuilles de Davis.Les tests avec des extraits dans l'acétate d'éthyle et l'hexane de feuilles provenant de différentes positions de PI 227687 et Davis, destinés à mettre en évidence des phagodissuadants, ont montré que la résistance observée chez les feuilles apicales de Davis était attribuable aux trichomes (c'est-à-dire à un caractère morphologique), tandis que chez les mêmes feuilles de PI 227687 elle impliquait à la fois des trichomes (morphologie) et des substances chimiques, mais avec une prédominance de l'influence des trichomes.

     

Oviposition behaviour of Dasineura brassicae on a high- versus a low-quality Brassica host

The oviposition behaviour of the brassica pod midge, Dasineura brassicae Winn. (Diptera: Cecidomyiidae), on a preferred host, Brassica napus L. (summer oilseed rape) was compared to that on a nonpreferred, less suitable host for larval growth, Brassica juncea (L.) Coss & Czern (brown mustard). The experiments were done under field conditions with wild females.The number of landing females was significantly higher on B. napus than on B. juncea, indicating host differences in olfactory and/or visual stimuli. After landing, the behaviour differed in that females stayed longer and laid more egg batches on B. napus than on B. juncea plants. The probability that oviposition would occur after landing and the potentially adjustable egg batch size were similar on the high- and the low-quality host.A larger egg load on B. napus than on B. juncea can thus be attributed mainly to a higher landing rate and more repeated ovipositions occurring on B. napus.

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Comportement de ponte de Dasineura brassicae sur des Brassica de qualites élevée et basse

Résumé La comparaison porte sur le comportement de ponte de D. brassicae Winn. (Dept. Cecidomyiidae) sur Brassica napus L., hôte préféré, et sur B. juncea L., hôte non-préféré, qui convient moins au développement larvaire. Les expériences réalisées en champ ont porté sur des femelles sauvages.Le nombre de femelles qui atterrissent sur B. napus est significativement plus élevé que sur B. juncea, ce qui indique des différences entre les stimuli olfactif et visuel des plantes-hôtes. Aprés atterrisage, le comportement diffère en ce que les femelles restent plus longtemps et déposent plus de pontes sur B. napus que sur B. juncea. La probabilité pour que la ponte suive l'atterrissage et les tailles des ooplaques potentiellement ajustables sont semblables sur les hôtes de qualité élevée ou basse.Une charge supérieure en oeufs sur B. napus que sur B. juncea peut ainsi être principalement attribuée à un taux d'atterrissage plus élevé et à une plus grande fréquence de ponte sur B. napus.

     

Cucurbitacins and predation of the spotted cucumber beetle, Diabrotica undecimpunctata howardi

Two hypotheses about the ralationship of diabroticina beetles and plants in the family Cucurbitaceae are tested: (1) evolution of sensory receptors for cucurbitacins by diabroticina beetles was in part due to the predator protection offered by ingestion of these compounds, and (2) commercial varieties of cucurbitacin-producing cucumber offer Diabrotica undecimpunctata howardi Barber chemical protection from some potential sources of natural controlSpotted cucumber beetles fed either Marketmore 70 cucumber which contains cucurbitacin-C or Marketmore 72 which totally lacks cucurbitacin were presented to four species of vertebrate predators that commonly occur in the summer and/or winter habitats of D. u. howardi: Bufo americanus, B. fowleri, Peromyscus maniculatus, Colinus virginianus. None of the four species were significantly deterred from preying on beetles that had eaten Marketmore 70 cucumber. These results do not support either of the two hypotheses. The limitations of these negative results as evidence for refutation of the first hypothesis are discussed.

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Résumé Deux hypothèses concernant les relations entre les Diabroticina et les Cucurbitaceae ont été examinées: (1) l'évolution chez les Diabroticina des récepteurs pour les Cucurbitacines est due en partie à la protection contre les prédateurs apportée par la consommation de ces produits (2) les variétés modernes de concombres produisant de la cucurbitacine fournissent à D. undecimpunctata howardi Barber une protection chimique contre quelques sources potentielles de lutte biologique.Des D. undecimpunctata howardi, ayant consommé soit des concombres Marketmore 70 contenant de la cucurbitacine C, soit des concombres Marketmore 72 qui ont totalement perdu leur cucurbitacine, ont été présentés à quatre espèces de vertébrés prédateurs, qui s'observent fréquemment dans les habitats d'été ou d'hiver de D. undecimpunctata howardi soient Bufo americanus, B. fowleri, Peromyscus maniculatus, Colinus virginianus. Aucune de ces quatre espèces n'est significativement dissuadée d'attaquer les coléoptères qui on consommé les concombres Marketmore 70. Ces résultats n'étayent aucune des deux hypothèses. La discussion porte sur les limites de ces résultats négatifs comme preuve de la réfutation de l'hypothèse 1.

     

Cloning and expression of the α-amylase gene and oxytetracycline production in Streptomyces rimosus

An 8.4 kb Sau3AI DNA fragment containing the Streptomyces rimosus TM-55 -amylase gene (amy) was ligated to a vector pIJ702, named pCYL01, and cloned into amylase deficient mutant S. lividans M2 (amy ^–). Subcloning study showed that the amy gene was localized in 3.3 kbKpnI-PstI fragment. The molecular weight of the purified -amylases of S. lividans M2/pCYL01 and S. rimosus TM-55 were estimated to be 65.7 kDa. Different sizes of recombinant plasmids carrying the amy gene had been retransferred into the parental strain of S. rimosus TM-55. Among these S. rimosus transformants, TM-55/pCYL01, TM-55/pCYL12 and TM-55/pCYL36 showed amylase activity 1.36- to 2.05-fold at the seventh day (1.61 to 2.42 units vs 1.18 units), and oxytetracycline (OTC) production 2.00- to 2.50-fold at the ninth day (approximate 140 to 170 g ml^–1 vs 72 g ml^–1), higher than that of S. rimosus TM-55 alone, respectively. These results showed that industrial microorganisms could be improved by genetic and metabolic engineering.     

Discrimination of alfalfa weevil strains by allozyme analysis

Allozyme profiles of eastern weevils (Beltsville, Maryland; Washington Co., Illinois), western weevils (Logan and St. George, Utah), and Egyptian weevils (Yuma, Arizona; Westmorland, California) were compiled by acrylamide gel electrophoresis. Twenty-two gene loci from 12 enzymes (ACPH, ADH, AMY, AO, EST, GOT, G-6PDH, MDH, ME, SOD, TYR, XDH) were analyzed. Mean heterozygosity of these populations was 0.231, with an average proportion of polymorphic loci of 0.536. The mean genetic distance of all weevil populations was 0.033 and the fixation index was 0.024. Diagnostic loci were found which could distinguish western weevils from eastern and Egyptian weevils. The small genetic distance between the eastern and Egyptian weevils suggests that they may be the same strain and are certainly different from the western weevil strain. Based on this and other evidence, we conclude that all weevil strains in the United States are Hypera postica (Gyllenhal), and that the use of H. brunneipennis (Boheman) for the Egyptian alfalfa weevil of North America should be discontinued.

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Résumé Les allozymes d'Hypera de l'est des USA (Beltsville, Maryland; Washington Co., Illinois), de l'ouest des USA (Logan et St Georges, Utah) et égyptiens (Yuma, Arizona; Westmorland, Californie) ont été analysés par électrophorèse sur gel d'acrylamide. L'étude a porté sur 22 loci de 12 enzymes (ACPH, ADH, AMY, AO, EST, GOT, G-6PDH, MDH, ME, SOD, TYR, XDH). L'hétérozygotie moyenne de la population était 0.231, avec une moyenne de loci polymorphes de 0.536. La distance génétique moyenne de l'ensemble des populations était de 0.033 et l'indice de fixation de 0.024. Des loci caractéristiques ont été trouvés qui pourraient permettre de distinguer les Hypera occidentaux des orientaux et des égyptiens. La faible distance génétique entre les Hypera orientaux et égyptiens suggère qu'ils appartiennent à la même souche et sont certainement différents des occidentaux. A partir de cela et d'autres éléments, nous concluons que tous les Hypera des USA sont H. postica Gyllenhal et que l'utilisation d'H. brunneipennis Boheman pour désigner les Hypera égyptiens d'Amérique du Nord doit être abandonnée.

     

Development and survival of Telenomus lobatus, a parasitoid of chrysopid eggs: effect of host species

Telenomus lobatus Johnson & Bin (Hymenoptera: Scelionidae), previously known only from the eggs of a berothid species, emerged from field-collected eggs of the chrysopid Mallada macleodi. In the laboratory, host species differentially influenced development, survival, and size of the parasitoid. Females parasitized between 55 and 65% of the available eggs of Chrysoperla (C. carnea, C. harrisii, and C. rufilabris), and these yielded 98 to 100% adult parasitoids within an average of 13 days. In contrast, eggs of Chrysopa were parasitized less frequently, (C. chi: 50%; C. oculata: 16%; C. quadripunctata: 1.3%) and relatively few (C. chi: 5.6%; C. oculata: 21%) or no (C. quadripunctata) parasitoids survived to adult emergence. Preimaginal development of T. lobatus in eggs of C. chi and C. oculata was approximately two days longer than in eggs of Chrysoperla spp. Although eggs of Meleoma dolicharthra were parasitized infrequently (approx. 16%), they yielded 100% adult parasitoids. Anomalochrysa maclachlani eggs were parasitized at low rates (1.8%) and parasitoid survival was intermediate (40.7%). Among all species, size of the host egg was positively related to the size of the emerging parasitoid adult.

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Résumé T. lobatus Johnson & Bin (Hym. Scelionidae) connu jusqu'ici uniquement comme parasitoïde des ufs de Berothidae, a étè obtenu d'ufs du chrysope, Mallada macleodi récoltés dans la nature. Au laboratoire, l'espèce de l'hôte influe sur le développement, la survie et la taille du parasitoïde. Les femellles ont parasité 55 à 65% des ufs disponibles de Chrysoperla (C. carnea, C. harrisii, C. rufilabris) et ceux-ci ont donné 98 à 100% de parasitoïdes adultes en 13 jours en moyenne. Par contre, les ufs de Chrysopa étaient moins souvent parasités,-C. chi: 50%; C. oculata: 16%; C. quadripunctata: 1,3%-, et relativement peu de parasitoïdes avaient survecu jusqu'à l'émergence,-C. chi: 5,6%; C. oculata: 21%; C. quadripunctata: 0. Le développment préimaginal est approximativement 2 jours plus long dans les ufs de C. chi et C. oculata que dans ceux de Chrysoperla spp. Bien que les ufs de Meleoma dolicharthra aient été peu parasités,-environ 16%-, 100% ont donné des parasitoïdes adultes. Les ufs de Anomalochrysa maclachlani ont été peu parasités,-1,8%-, et le taux de survie a été moyen: 40,7%. Pour toutes les espèces, la taille de l'uf de l'hôte était liée positivement à la taille du parasitoïde obtenu.

     

Z-linked inheritance of male olfactory response to sex pheromone components in two species of tortricid moths, Ctenopseustis obliquana and Ctenopseustis sp.

The olfactory response from male pheromone sensitive sensilla was investigated in the endemic New Zealand brownheaded leafrollers Ctenopseustis obliquana (Walker) and C. sp. ropeana (Lepidoptera, Tortricidae). The responses from 281 sensilla from the parental strains and from both the reciprocal crosses, including F₁, F₂ and maternal and paternal backcrosses were recorded, and statistically analysed using a multivariate analysis.In males of both the parental strains, a large amplitude cell responded to the main pheromone component of the conspecific female, in C. obliquana (Z)-8-tetradecenyl acetate (Z8-14:OAc) and in C. sp ropeana (Z)-5-tetradecenyl acetate (Z5-14:OAc). Both male types also possessed a small amplitude cell, which in C. obliquana responded weakly to Z5-14:OAc and tetradecyl acetate (14:OAc), and in C. sp ropeana responded to Z8-14:OAc. The responses from the different types of hybrid males were more variable than the responses from parental males. A main pattern could, however be seen, corresponding with the expected pattern in a sex-linked inheritance on the Z-chromosome of a C. sp ropeana type dominant genetic factor. The more pronounced variation in the hybrids could not be explained by this model, and might be due to the involvement of additional genes.

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Résumé Les réactions olfactives des sensilles mâles sensibles aux phéromones ont été examinées par enregistrement de l'extrémité de la sensille chez les tordeuses C. obliquana Walker et C. sp. ropeana. Les enregistrements ont porté sur 281 sensilles des lignées parentales et des croisements réciproques de F₁, F₂ et de croisements en retour maternel et paternel. Les résultats des enregistrements d'une sensille ont été soumis à une analyse en composantes principales.Chez les mâles de chaque lignée parentale un seul type physiologique de sensille a été découvert; une cellule répond par un pic grand au principal constituant de la phéromone femelle conspécifique. (Z)-8-acétate tétradécényl (Z8-14:OAc) pour C. obliquana, et (Z)-5-acétate tétradécényl (Z5-14:OAc) pour C. sp. ropeana. Une seconde type de cellule dans les sensilles des deux espèces de mâles présente un pic petit pour Z5-14:OAc et pour l'acétate tétradécyl (14:OAc) chez C. obliquana, et pour C. sp. ropeana au Z8-14:OAc. Les réponses des sensilles des différents types de mâles hybrides sont plus hétérogènes que celles des sensilles de leurs pères. Un schéma général pourrait cependant être décelé, correspondant au schéma prévu avec une hérédité d'un facteur dominant liée au sexe sur le chromosome Z de C. sp. ropeana. La variation plus accentuée chez les hybrides ne peut être expliquée par ce modèle, et pourrait impliquer des gènes additionnels.

     

Encapsulation of micropropagated buds of six woody species

Regrowth after encapsulation in a sodium alginate matrix of micropropagated buds from six different in vitro proliferated woody species was evaluated. Actinidia deliciosa Liang & Ferguson (kiwifruit), Betula pendula Roth (birch), Crataegus oxyacantha L. (hawthorn), Malus spp. (apple), Rubus spp. (blackberry) and Rubus idaeus L. (raspberry) propagated in vitro were used as bud sources. Encapsulation with sodium alginate and subsequent regrowth on nutrient rich medium was compared to encapsulation with nutrient-enriched alginate capsules followed by regrowth on nutrientless medium. Apical and sub-apical buds of Malus (rootstock M. 27 and cultivar Starkspur Red) were also compared for encapsulation and regrowth ability. All species showed a regrowth after encapsulation, but only if cultured on enriched media. M.27 apical and sub-apical buds showed different regrowth ability after encapsulation with sodium alginate. Applicability of encapsulation of single micropropagated tree buds is discussed.     

Fagus silvatica L. und das aceri-fagetum an der alpinen Waldgrenze in Mitteleuropäischen gebirgen

Summary In the Central Europaean mountain ranges, the alpine timberline is usually formed by Picea abies or by other conifers (Larix decidua, Pinus mugo, Pinus cembra). Unlike in the East Europaean mountains, the Balkan Peninsula, the Europaean Mediterranean and Les Vosges, Fagus silvatica occurs sporadically on the alpine timberline in this area where it forms very specific woods.This type of the alpine timberline is bound to the association Aceri-Fagetum (Bartsch 1940, Moor 1952). This association is found on the highest sites of the Fagion alliance in the subalpine vegetation zone. Within this zone, the association is bound to localities with heavy snowfall and a submaritime climat. It occupies larger areas in the Swiss Jura and in Les Vosges. In other Central Europaean mountains (the Alps, Schwarzwald, Krkonoe etc.) it occus in isolated areas only.Many trunk deformations and bush forms are found with Fagus on a large scale in the snow impacted localities (steep slopes, periphery of corries, avalanche slopes etc.). Crawling and sliding snow causes these growth deformations in the Fagus seedlings since their first year.The general increase of the vegetative propagation is a remarkable and exceptional response of Fagus in adapting to these extreme growth conditions. Under alpine timberline conditions, the generative propagation is very limited.The vegetative shoots with adventitious root systems are formed mainly from branches layering in the humus. The typical monocormonal tree-form of Fagus from lower altitudes turns in this way into a polycormon. From an evolutionary point of view, it is a suitable substitution; but from the ecological viewpoint, however, it is a sturdy growth form. In its typical form, the polycormon is formed by a number of vegetative shoots, which may be deformed but are very elastic and resistent. The number of shoots in a polycormon varies from 3–5 below, and up to 40–50 at and above the timberline. They are formed by shoots of a number of filial successions. The decay of a polycormon results from decreasing vitality of single shoots or, very often, it is caused by the impact of snow and ice. Considering, however, the fact that single shoots have a sufficient adventitious root system and are thus physiologically independent, the dying of the other shoots does not mean a danger for the existence of the remaining part of the polycormon. The age of a polycormon as a whole is difficult to determine. Fagus polycormons can be considered as a typical growthform of the highest sites of the association Aceri-Fagetum. No other tree species is able to form close stands under these conditions. This phenomenon is of primary importance for the existence of this plant community.The unusual character of the structure and dynamics of the highest Aceri-Fagetum stands gives rise to a special type of the alpine timberline which should be understood not as a line but as a transitional zone between the closed stands and the hon-wooded plant communities of the subalpine vegetation zone. The dynamic succession of the Fagus polycormons guarantees the stability of the Fagus stands forming the alpine timberline.

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Fagus silvatica L. und das aceri-fagetum an der alpinen Waldgrenze in Mitteleuropäischen gebirgen

     

The effect of juvenile hormone and its antagonists on JH esterase activity in Tenebrio molitor

The hemolymph juvenile hormone esterase (JHE) and general carboxyl esterase activities in Tenebrio molitor show independent development-associated changes during larval-pupal and pupal-adult metamorphoses. JHE activity was high in pharate pupae and early pupae. Unlike in lepidopteran pupae that have been studied thus far, JH had no effect on JHE activity in pupae and pharate adults of Tenebrio. A JH antagonist, ethyl 4,2,tert butyl carboxy n benzoate (ETB), and 20-hydroxyecdysone had no effect on JHE activity. These observations suggest that although JHE activity in Tenebrio is precisely regulated during larval-pupal metamorphosis, JH and molting hormone do not appear to be involved in its regulation and that the proximate cues that influence JHE activity in Tenebrio pupae are different from that of lepidopterans.

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Résumé Les activités JHE (estérase juvénile hormone) de l'hémolymphe et carboxyl estérase générale de T. molitor changent indépendamment du développement pendant les métamorphoses larve-nymphe et nymphe-adulte. L'activité JHE est élevée chez les prénymphe et les jeunes nymphes. Contrairement aux chrysalides de papillons, JH n'a pas d'effet sur l'activité JHE chez les nymphes et les préadultes de Tenebrio. Un antagoniste de JH, l'éthyl 4,2,tert butyl carboxy n benzoate (ETB), 20-hydroxyecdysone et le précocène 2-agent anti-allate chez plusieurs insectes-, n'ont aucun effet sur l'activité JHE. Ces observations suggèrent que, bien que l'activité JHE chez T. molitor soit ajustée avec précision pendant la métamorphose larvo-nymphale, JH et hormone de mue ne paraissent pas être impliquées dans sa régulation et que les signaux immédiats, qui influent sur l'activité JHE de la nymphe de T. molitor, diffèrent de ceux des Lépidoptères.

     

Conformation of the circular dumbbell d〈pCGC-TT-GCG-TT〉: Structure determination and molecular dynamics

Summary The circular DNA decamer 5-dpCGC-TT-GCG-TT-3 was studied in solution by means of NMR spectroscopy and molecular dynamics in H₂O. At a temperature of 269 K, a 50/50 mixture of two dumbbell structures (denoted L2L2 and L2L4) is present. The L2L2 form contains three Watson-Crick C-G base pairs and two two-residue loops in opposite parts of the molecule. On raising the temperature from 269 K to 314 K, the L2L4 conformer becomes increasingly dominant (95% at 314 K). This conformer has a partially disrupted G(anti)-C(syn) closing base pair in the 5-GTTC-3 loop with only one remaining (solvent-accessible) hydrogen bond between NH of the cytosine dC(1) and O6 of the guanine dG(8). The opposite 5-CTTG-3 loop remains stable. The two conformers occur in slow equilibrium (rate constant 2–20 s^–1). Structure determination of the L2L2 and L2L4 forms was performed with the aid of a full relaxation matrix approach (IRMA) in combination with restrained MD. Torsional information was obtained from coupling constants. Coupling constant analysis (³J_HH, ³J_HP, ³J_CP) gave detailed information about the local geometry around backbone torsion angles , , and , revealing a relatively high flexibility of the 5-GTTC-3 loop. The values of the coupling constants are virtually temperature-independent. Weakly constrained molecular dynamics in solvent was used to sample the conformational space of the dumbbell. The relaxation matrices from the MD simulation were averaged over r^–3 to predict dynamic NOE volumes. In order to account for the 1:1 conformational mixture of L2L2 and L2L4 present at 271 K, we also included S² factors and r^–6 averaging of the r^–3-averaged relaxation matrices. On matrix averaging, the agreement of NOE volumes with experiment improved significantly for protons located in the thermodynamically less stable 5-GTTC-3 loop. The difference in stability of the 5-CTTG-3 and 5-GTTC-3 loops is mainly caused by differences in the number of potential hydrogen bonds in the minor groove and differences in stacking overlap of the base pairs closing the minihairpin loops. The syn conformation for dC(1), favored at high temperature, is stabilized by solvation in the major groove. However, the conformational properties of the dC(1) base, as deduced from R-factor analysis and MD simulations, include a large flexibility about torsion angle .     

Distribution in time and space of resistance to the pathogenic fungus Erynia neoaphidis in the pea aphid Acyrthosiphon pisum

Two biotypes of pea aphid, Acyrthosiphon pisum, have been recognized in Australia, by their susceptibility (S) or resistance (R) to certain isolates of the fungal pathogen Erynia neoaphidis. The responses of these two biotypes to 40 isolates of the fungus have shown that the R form is largely confined to two States, New South Wales and Victoria, but appears to have recently spread into Queensland and Tasmania. There is no evidence to suggest it occurs outside Australia. Sequential sampling of two field populations of pea aphids during 1981 and 1982 showed that the proportion of R form remained stable at 10.7±3.0 and 14.6±2.6% (mean±standard error) for the two populations. Glasshouse competition experiments run at the comparatively high temperature of 25°C resulted in the R form becoming dominant even when the initial ratio was 4:1 in favour of the S form. The ecological and genetical implications are discussed.

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Résumé Deux types biologiques d'Acyrthosiphon pisum ont été définis, en Australie, suivant leur sensibilité (S) ou leur résistance (R) à certains isolats du champignon pathogène Erynia neoaphidis. Les réponses des deux biotypes à 40 isolats du champignon ont montré que la forme R est essentiellement cantonnée à deux états: Nouvelle Galle due Sud et Victoria, mais a récemment gagné le Queensland et la Tasmanie. Aucun élément ne fait dire qu'elle existe hors d'Australie. Des échantillonnages séquentiels des deux populations de pucerons dans la nature en 1981 et 1982 ont montré que la proportion de la forme R est restée stable à 10,7 et 14,62 dans les deux populations. Des expériences de compétition en serre à la température relativement haute de 25°C ont rendu la forme R dominante, même quand le rapport initial était de 4/1 en faveur de la forme S. La discussion porte sur les conséquences écologiques et génétiques.

     

Assessment of quality control parameters during mass rearing of a pupal colour genetic sexing strain of the Mediterranean fruit fly

Quality control charts were employed to monitor the quality of several parameters during mass rearing of the T : Y(wp ⁺)30C strain of Ceratitis capitata (Wiedemann), in which male and female flies emerge from brown and white puparia, respectively. Egg hatch and pupal recovery in this genetic sexing strain were below that reported for a wild-type Sohag strain, whereas pupal size, adult emergence and flight ability were higher. The overall recovery from eggs to adult flies capable of flight was similar in the two strains but egg production in T:Y(wp ⁺)30C was reduced to about 56% of that of Sohag. The quality control charts showed an acceptable level of variation within sets of data but the level between data sets was occasionally out of control. This indicated the presence of uncontrolled conditions during the rearing process, possibly arising from variations in the quality of the larval diet. It is concluded that the quality of T : Y(wp ⁺)30C renders this strain suitable for mass rearing in sterile insect technique (SIT) programmes requiring the elimination of the female flies prior to the release of sterilized males. The next step should involve further quality assessments both under field cage and under field release conditions. The importance of optimal and standardized dietary conditions is stressed in relation to the quality of mass reared medflies.

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Résumé Des normes de qualité ont été utilisées pour relever la valuer de plusieurs paramètres lors de l'élevage industriel de la souche T : Y(wp ⁺)30C de C. capitata Wied. dont les mâles et les femelles émergent respectivement de pupes brunes et blanches. Les taux d'éclosion et d'obtention de pupes sont plus faibles avec cette souche qu'avec la souche souvage Sohag; par contre, la taille des pupes, le taux d'émergence des adultes et l'aptitude au vol étaient plus élevés. La fréquence totale des adultes capables de voler par rapport au nombre initial d'ufs a été de 0,297 contre environ 0,311 pour Sohag. Cependant, la production d'ufs a été réduite à environ 56% de celle de Sohag. Les tableaux de contrôle de la qualité ont révélé un niveau de variation acceptable à l'interieur rieur des lots de données, mais la variabilité entre les lots excédait les normes admissibles. Ceci implique des paramètres incontrôlés pendant l'élevage de masse, probablement liés à des variations de la qualité de l'aliment. On peut en conclure que la qualité de la souche T : Y(wp ⁺)30C la rend utilisable pour un élevage de masse dans des programmes d'utilisation d'insectes stériles (SIT) exigeant l'élimination des femelles avant le lâcher de mâles stériles. La prochaine étape impliquera de nouvelles épreuves de qualité dans des cages en champ et dans les conditions de libération dans la nature. L'importance des conditions optimales d'une alimentation standardisée est soulignée par la qualité des mouches obtenues en élevage de masse.