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International audience; To investigate whether landscape structures act as insurmountable barriers for foraging bees, we conducted mark-recapture studies with two pollen-specialist solitary species. Foraging options of the bees were confined to host plant stands across different landscape structures. Differences in altitude of more than 130 m were overcome and forests covering a distance of up to 480 m were crossed by Chelostoma florisomne. A broad river and a motorway with intense traffic did not represent insurmountable barriers for Hoplitis adunca. For C. florisomne, total foraging distances of up to 650 m were measured, but foraging females were recorded predominantly on host plant patches available in relatively close vicinity to their nesting site. While landscape structures might impede foraging in endangered bees, the investigated landscape structures clearly did not act as insurmountable physical barriers for the two common solitary bee species tested in our study.

Journal of Insect Conservation, 11 (3), ISSN:1366-638X, ISSN:1572-9753

In the highly fragmented landscape of central Europe, dispersal is of particular importance as it determines the long-term survival of animal populations. Dispersal not only secures the recolonization of patches where populations went extinct, it may also rescue small populations and thus prevent local extinction events. As dispersal involves different individual fitness costs, the decision to disperse should not be random but context-dependent and often will be biased toward a certain group of individuals (e.g., sex- and wing morph-biased dispersal). Although biased dispersal has far-reaching consequences for animal populations, immediate studies of sex- and wing morph-biased dispersal in orthopterans are very rare. Here, we used a combined approach of morphological and genetic analyses to investigate biased dispersal of Metrioptera bicolor, a wing dimorphic bush-cricket. Our results clearly show wing morph-biased dispersal for both sexes of M. bicolor. In addition, we found sex-biased dispersal for macropterous individuals, but not for micropters. Both, morphological and genetic data, favor macropterous males as dispersal unit of this bush-cricket species. To get an idea of the flight ability of M. bicolor, we compared our morphological data with that of Locusta migratoria and Schistocerca gregaria, which are very good flyers. Based on our morphological data, we suggest a good flight ability for macropters of M. bicolor, although flying individuals of this species are seldom observed.

The stability and long-term survival of animal populations in fragmented landscapes largely depends on the colonisation of habitat patches and the exchange of individuals between patches. The degree of inter-patch dispersal, in turn, depends on the dispersal abilities of species and the landscape structure (i.e. the nature of the landscape matrix and habitat distribution). Here, we investigated the genetic structure of populations of Metrioptera bicolor, a wing-dimorphic bush cricket, in a spatially structured landscape with patches of suitable habitat distributed within a diverse matrix of different habitat types. Using six microsatellite markers, we assessed the effects of geographic distance and different matrix types on the extent of genetic differentiation among 24 sampling sites. We found that forest and a river running through the study area both impede inter-patch dispersal. The presence of these two matrix types was positively correlated with the extent of genetic differentiation between sites. In addition, we found a significant positive correlation between pairwise genetic and geographic distances for a subsample of sites which were separated only by arable land or settlements. For the complete data set, this correlation could not be found. This is most probably because the adverse effect of forest and river on gene flow dominates the effect of geographic distance in our limited set of patches. Our analyses clearly emphasize the differential resistance of different habitat types on dispersal and the importance of a more detailed view on matrix “quality” in metapopulation studies.

Protandry, the earlier adult emergence of males, is explained as either an adaptive strategy maximizing male mating opportunities at the same time as minimizing female pre-reproductive mortality, or as an incidental by-product of sexual dimorphism fuelled by selection for other life-history traits. Adult emergence sequences are monitored of broods of the gregarious larval endoparasitoid Cotesia glomerata L. (Hymenoptera: Braconidae) undergoing pupal development under different temperature regimes. As a haplodiploid species with single-locus complementary sex determination, gender in C. glomerata is determined by the genotype at one sex locus. Haploids are always male, whereas diploids are female when heterozygous but male when homozygous at the sex locus. Sibling mating promotes homozygosity and thus the production of diploid males. Diploid males are produced at the expense of females, and impose a genetic burden on individuals and populations, despite their exceptional fertility in C. glomerata. Emergence of broods is typically completed within 2 days. Irrespective of temperature, males emerge earlier and within a shorter time interval than females, and a majority of the males in a cluster emerge before the first female. The implications of an incomplete temporal segregation of the sexes on the incidence of inbreeding in C. glomerata are discussed in the light of its sex determination mechanism and its patterns of mating, host exploitation and natal dispersal.

The ability of a sufficient number of individuals to disperse is crucial for long-term survival of populations. However, dispersal is often energetically costly, and thus is expected to trade-off against other life-history traits. In insect pest species, the occurrence of individuals with high flight activity challenges management practices. We performed artificial selection on flight activity and measured correlated responses to selection in the oriental fruit moth, Grapholita (= Cydia) molesta, a widely distributed and expanding lepidopteran pest of fruit crops. Both sexes rapidly responded to the imposed regime of divergent selection, indicating an adaptive potential of flight activity in this species. Upward-selected moths died sooner than downward-selected ones, providing evidence for a cost of flight activity to adult survival, reputedly associated with enhanced metabolic rates. Oppositely-selected females had similar total reproductive output, disproving a trade-off between dispersal and reproduction, although females with higher flight activity laid their eggs sooner. The ratio of body weight to forewing surface (forewing loading) did not significantly differ between selected lines. The present study contributes to the understanding of dispersal evolution, and also provides new insights into life-history theory as well as important baseline data for the improvement of pest management practices. © 2010 The Linnean Society of London, Biological Journal of the Linnean Society, 2010, 100, 879‐889.

Intercontinental trade has led to multiple introductions of invasive pest species at a global scale. Molecular analyses of the structure of populations support the understanding of ecological strategies and evolutionary patterns that promote successful biological invasions. The oriental fruit moth, Grapholita (= Cydia) molesta, is a cosmopolitan and economically destructive pest of stone and pome fruits, expanding its distribution range concomitantly with global climate warming. We used ten newly developed polymorphic microsatellite markers to examine the genetic structure of G. molesta populations in an agricultural ecosystem in the Emilia-Romagna region of northern Italy. Larvae collected in eight sampling sites were assigned to a mosaic of five populations with significant intra-regional structure. Inferred measures of gene flow within populations implicated both active dispersal, and passive dispersal associated with accidental anthropogenic displacements. Small effective population sizes, coupled with high inbreeding levels, highlighted the effect of orchard management practices on the observed patterns of genetic variation within the sampling sites. Isolation by distance did not appear to play a major role at the spatial scale considered. Our results provide new insights into the population genetics and dynamics of an invasive pest species at a regional scale.

Summary 1. Solitary bees are central place foragers returning to their nests several times a day with pollen and nectar to provision their brood cells. They are especially susceptible to landscape changes that lead to an increased spatial separation of suitable nesting sites and flower rich host plant stands. While knowledge of bee foraging ranges is currently growing, quantitative data on the costs of foraging flights are very scarce, although such data are crucial to understand bee population dynamics. 2. In this study, the impact of increased foraging distance on the duration of foraging bouts and on the number of brood cells provisioned per time unit was experimentally quantified in the two pollen specialist solitary bee species Hoplitis adunca and Chelostoma rapunculi. Females nesting at different sites foraged under the same environmental conditions on a single large and movable flowering host plant patch in an otherwise host plant free landscape. 3. The number of brood cells provisioned per time unit by H. adunca was found to decrease by 23%, 31% and 26% with an increase in the foraging distance by 150, 200 and 300 m, respectively. The number of brood cells provisioned by C. rapunculi decreased by 46% and 36% with an increase in the foraging distance by 500 and 600 m, respectively. 4. Contrary to expectation, a widely scattered arrangement of host plants did not result in longer mean duration of a foraging bout in H. adunca compared to a highly aggregated arrangement, which might be due to a reduced flight directionality combined with a high rate of revisitation of already depleted flowers in the aggregated plant arrangement or by a stronger competition and disturbance by other flower visitors. 5. The results of this study clearly indicate that a close neighbourhood of suitable nesting and foraging habitats is crucial for population persistence and thus conservation of endangered solitary bee species.

To preserve populations of endangered bee species, sound knowledge of their maximum foraging distance between nest and host plants is crucial. Previous investigations predicted maximum foraging distances of 100–200 m for small bee species and up to 1100 m for very large species based on mainly indirect methods. The present study applied a new and direct approach to experimentally investigate maximum foraging distances in solitary bees. One endangered and two common species of different body sizes, all of which restrict pollen foraging to a single plant genus, were established in a landscape lacking their specific host plants. Females were forced to collect pollen on potted host plants that were successively placed in increasing distance from fixed nesting stands. The maximum foraging distance recorded for the small Hylaeus punctulatissimus was 1100 m, for the medium sized Chelostoma rapunculi 1275 m and for the large Hoplitis adunca 1400 m, indicating that maximum foraging distances at species level have been underestimated. However, the capability to use resources on such a large spatial scale applied only to a small percentage of individuals as 50% of the females of H. punctulatissimus and H. adunca did not forage at distances longer than 100–225 m and 300 m, respectively. This finding suggests that a close neighbourhood of nesting and foraging habitat within few hundred meters is crucial to maintain populations of these species, and that threshold distances at which half of the population discontinues foraging are a more meaningful parameter for conservation practice than the species specific maximum foraging distances.

The survival of hymenopteran populations especially that of ecologically and economically important pollinators and parasitoids, has become a major topic for empirical and theoretical studies. Complementary sex determination (CSD) in Hymenoptera may impose a substantial genetic load through the production of inviable or sterile diploid males. Modelling and laboratory studies have indicated that this genetic load may trigger a ‘diploid male vortex’ leading to rapid extinction of populations. Here we take a broader theoretical approach to analyze why populations exhibiting CSD persist in nature, even if they contain large proportions of homozygous diploid individuals. Using an individual-based model of spatially structured hymenopteran populations, we show that (i) inviability or reduced fertility of homozygous individuals, (ii) female-biased sex ratio, and (iii) strong intra-specific competition can mitigate the negative influence of CSD on population persistence and that (iv) already extremely low dispersal rates will result in long term survival. These findings underline the importance of life history traits for population survival and demonstrate that rather specific conditions must be met to initiate the ‘diploid male vortex’.

Summary For the design and declaration of conservation areas as well as for planning habitat management it is important to quantitatively know the habitat preferences of the focal species. To take into account the requirements of as many species as possible, it would be of great advantage if one would either (i) find one or several species whose habitat requirements cover those of a large number of other species or if one could (ii) identify a common set of habitat parameters that is important for the occurrence of many species. Ideally such common habitat parameters should be easy to measure. Only then they may be of practical value in applied conservation biology. In this study, we compared the habitat preferences of different insect species (grasshoppers, bush crickets, butterflies, moths) in the same region by applying identical methods. To identify common explanatory variables that predict the occurrence probability of these species, we first tested the transferability of the specific ‘species models’ to other species within the same insect group. We tested how well the incidence of one species can be predicted by the occurrence probability of another species. The ‘best’ models within each group were then tested for transferability between the different groups. Additionally, we tested the predictive power of the predictor variable ‘habitat type’ as an easy and often available measure for conservation practice. Although in the different ‘species models’ different key factors determine habitat suitability, some models were successfully transferred and were able to reasonably predict the distribution of other species. The habitat preferences of the burnet moth Zygaena carniolica were particularly well suited for the prediction of suitable habitats for all other species. In addition, the predictor variable ‘habitat type’ played a dominant role in all models. Models using this aggregated predictor variable may well predict suitable habitat for all species.

Flowering plant strips providing nectar food sources at field edges might influence habitat exploitation by parasitoids, and are therefore of great interest for biological control. The present field study examines the host-foraging movement of the parasitoid, Cotesia glomerata (L.) (Hymenoptera: Braconidae), and the resulting distribution pattern of parasitism in Pieris brassicae (L.) (Lepidoptera: Pieridae) larvae in cabbage fields in the presence of floral nectar plants. Parasitoids were released in the center of 35 × 35 m field patches with flowering dill plants, Anethum graveolens L. (Apiaceae), arranged at two diagonally opposing corners, and non-flowering dill plants at the other two corners. The movement of released parasitoids marked with the stable isotope 44 Ca was assessed based on parasitized host larvae on trap cabbage plants. This isotope marker is transferred from the parasitoid to host caterpillars through oviposition, and tracking of the marked wasps in the field was feasible in the presence of a native population by analyzing the sedentary host caterpillars. Data from two field trials with two trial areas each consistently showed that the parasitoid females dispersed over the entire cabbage field patches within 3 days and that the caterpillars parasitized by the released wasps were randomly distributed in space. Parasitism rates in sectors with and without flowering dill plants at the edges were not significantly different. In conclusion, C. glomerata females are able to cover the cabbage field patches of 1225 m 2 within 3 days, foraging for hosts, while food sources at field edges remain within their reach.

The aim of this study was the production of the homopolyester poly(4-hydroxybutyric acid) (poly(4HB)) with recombinant strains of Escherichia coli. Wild-type strains and other widely used non-recombinant strains of E. coli are not able to produce polyhydroxyalkanoic acids (PHA) as storage compounds and cannot utilize 4-hydroxybutyric acid as sole carbon source. Accordingly, hybrid plasmids of pBluescript vectors were constructed which harbored the Alcaligenes eutrophus PHA synthase gene (phaC) and the Clostridium kluyveri orfZ putatively encoding a 4-hydroxybutyric acid-coenzyme A transferase. A 3.5-kb genomic SmaI/ApaI fragment from A. eutrophus, which comprises phaC, and a 1.8-kb genomic ApaI/EcoRI fragment from C. kluyveri, which contained orfZ, were inserted into the SmaI and EcoRI sites of the vectors pKS− and pSK−, respectively. The two resulting plasmids pSKSE5.3 and pKSSE5.3 comprising phaC and orfZ colinear or antilinear to lacZ, respectively, were transformed into E. coli XL1-Blue. Recombinant strains synthesized the homopolyester poly(4HB), when the cells were cultivated in Luria-Bertani broth and if glucose and 4-hydroxybutyric acid were provided as carbon sources. If glucose was omitted, a copolyester of 3-hydroxybutyric acid and 4-hydroxybutyric acid was accumulated. The homopolyester poly(4HB) was also accumulated during cultivation of these strains in M9 mineral salts medium containing glucose plus 4-hydroxybutyric acid as carbon sources. Poly(4HB) could amount up to approximately 80% (w/w) of the cell dry matter if E. coli XL1-Blue harboring pKSSE5.3 was cultivated in M9 mineral salts medium and if the cultures were not sufficiently supplied with oxygen. 4HB was also incorporated into PHA if γ-butyrolactone was used as carbon source. If levulinic acid, 4-hydroxyvaleric acid or γ-valerolactone were used as carbon sources, only very low amounts of PHA were accumulated which did not contain 4-hydroxyalkanoic acids as constituents.

In metapopulation models it is common practice to use species-specific dispersal distances to predict the exchange of individuals between habitat patches. The influence of patch distribution on the reachability of a habitat patch is usually ignored. In a patch-matrix simulation, we investigated the effect of patch number, movement pattern and dispersal mortality on realised animal dispersal distances. In our spatially-explicit, individual-based simulations we demonstrate that: (1) with increasing number of patches the number of immigrants into patches further away from the release point decreases in all scenarios (“shadow effect”), (2) this effect is strongest for a random movement, (3) for rather uncorrelated walks a proper adjustment of mean dispersal distance in the negative exponential model can account for the effect of patch density on realised dispersal distances, (4) with a more directed walk this is not possible as the distribution of moving animals in the matrix becomes highly heterogeneous. This is due to the narrow but far reaching shadow patches exert on other patches further away from the release point.

1. Inter-patch movement is usually assumed to be homogeneous across a landscape. As the intervening area between suitable patches is usually richly textured, it cannot be assumed to be uniform in real landscapes. 2. In an experimental mark-and-resight study, the movement behaviour of the bush cricket Platycleis albopunctata in four habitat types as well as at the border between two of these habitat types was observed. 3. Analysis of recapture data indicated differences in mortality risk (or emigration rates) between habitat types. 4. When released at the border between suitable habitat and a crop field, P. albopunctata did not show a consistent preference for the suitable habitat. This suggests that the crop field is at least temporarily attractive for P. albopunctata. 5. Movement in suitable habitat was not always different from movement in the matrix, and movement between different types of matrix also differed. 6. The results indicate that the movement behaviour of P. albopunctata is influenced not only by suitability for breeding but also by structural resistance and other factors (e.g. food availability or habitat-specific mortality risk).

This study describes a comparison of the polyhydroxyalkanoate (PHA) synthases PhaC1 and PhaC2 of Pseudomonas mendocina. The P. mendocina pha gene locus, encoding two PHA synthase genes [phaC1Pm and phaC2Pm flanking a PHA depolymerase gene (phaZ)], was cloned, and the nucleotide sequences of phaC1Pm (1,677 bp), phaZ (1,034 bp), and phaC2Pm (1,680 bp) were determined. The amino acid sequences deduced from phaC1Pm and phaC2Pm showed highest similarities to the corresponding PHA synthases from other pseudomonads sensu stricto. The two PHA synthase genes conferred PHA synthesis to the PHA-negative mutants P. putida GPp104 and Ralstonia eutropha PHB–4. In P. putida GPp104, phaC1Pm and phaC2Pm mediated PHA synthesis of medium-chain-length hydroxyalkanoates (C6–C12) as often reported for other pseudomonads. In contrast, in R. eutropha PHB–4, either PHA synthase gene also led to the incorporation of 3-hydroxybutyrate (3HB) into PHA. Recombinant strains of R. eutropha PHB–4 harboring either P. mendocina phaC gene even accumulated a homopolyester of 3HB during cultivation with gluconate, with poly(3HB) amounting to more than 80% of the cell dry matter if phaC2 was expressed. Interestingly, recombinant cells harboring the phaC1 synthase gene accumulated higher amounts of PHA when cultivated with fatty acids as sole carbon source, whereas recombinant cells harboring PhaC2 synthase accumulated higher amounts when gluconate was used as carbon source in storage experiments in either host. Furthermore, isogenic phaC1 and phaC2 knock-out mutants of P. mendocina provided evidence that PhaC1 is the major enzyme for PHA synthesis in P. mendocina, whereas PhaC2 contributes to the accumulation of PHA in this bacterium to only a minor extent, and then only when cultivated on gluconate.

Eleven different cyanobacteria were investigated with respect to their capabilities to synthesize poly-3-hydroxybutyrate [poly(3HB)] and the type of poly-beta-hydroxyalkanoic acid (PHA) synthase accounting for the synthesis of this polyester. Several methods, including (i) Southern blot analysis using a phaC-specific DNA probe, (ii) Western blot analysis using specific polyclonal anti-PhaE antibodies raised in this study against PhaE of Synechocystis sp. strain PCC 6803, (iii) generation and sequence analysis of PCR products using phaC-specific oligonucleotides as primers, and/or (iv) cloning and sequence analysis of PHA synthase structural genes, were used to provide evidence for the presence of a type-III PHA synthase in the following cyanobacteria: Synechococcus sp. strains MA19 and PCC 6715, Chlorogloeopsis fritschii PCC 6912, Anabaena cylindrica SAG 1403-2, Cyanothece sp. strains PCC 7424, PCC 8303 and PCC 8801, and Gloeocapsa sp. strain PCC 7428. The screening was compared with corresponding studies using crude protein extracts and genomic DNA of Synechocystis sp. strain PCC 6803, as a positive control, which is so far the only cyanobacterium for which molecular data of the PHA synthase genes are available. No evidence for the presence of a type-III PHA synthase could be obtained for only three of the eleven investigated cyanobacteria (Stanieria sp. strain PCC 7437, Cyanothece sp. strain PCC 8955 and Gloeothece sp. strain PCC 6501). The entire PHA synthase structural genes of the two thermophilic cyanobacteria Synechococcus sp. strain MA19 and Chlorogloeopsis fritschii PCC 6912, and in addition a central region of the phaC gene of Cyanothece sp. strain PCC 8303, were cloned, sequenced and also heterologously expressed in Escherichia coli.

A genomic library of Ralstonia eutropha CH34 was screened in Escherichia coli S17-1 for esterase activity by using α-naphthyl acetate and Fast Blue RR. A 1,711 bp DNA fragment was subcloned from an esterase-positive clone and sequenced. Esterase EstA was encoded by a 825-bp open reading frame and exhibited significant amino acid similarities with the enzymes involved in the meta-cleavage pathway. EstA is composed of 275 amino aicds with a predicted molecular mass of 30785 Da. The optimal pH for EstA was 7.0, and the enzyme retained more than 65% activity when incubated in buffers with pH 3.8–9.2 for 2 h. EstA was active at temperatures up to 80 °C and retained more than 77% activity after exposure to temperatures below 60 °C for 2 h.

Many bacteria are able to synthesize polyesters of hydroxyalkanoic acids (PHA), which occur as insoluble cytoplasmic inclusions in the cell and can contribute significantly to the cellular dry matter. More than 100 different hydroxyalkanoic acids have been detected as constituents in PHA. This article summarizes strategies and possibilities to obtain these biodegradable and thermoplastic/elastomeric polymers by fermentation of wild-type bacteria as well as of mutants and recombinant strains from renewable resources, waste substrates or special precursor substrates. In addition, in vitro biosynthesis of PHA employing the purified polymerizing enzyme (PHA synthase) is described. Throughout analysis and cloning of the bacterial PHA biosynthesis genes enabled scientists to also establish this pathway in non-PHA producing eukaryotic organisms such as yeast, plants and animals. This will allow new processes for cheap and economic production of PHA.

Die exzellente Führung von Familienunternehmen ist für die deutsche Wirtschaft von zentraler Bedeutung. Um den Erfolg nachhaltig zu sichern, sind spezifische Führungs- und Kontrollstrukturen erforderlich, und eine starke Familie, die als Einheit hinter dem Unternehmen steht. Wie Sie die Führung von Unternehmen und Familie erfolgsorientiert ausrichten, erfahren Sie in diesem Leitfaden: mit allen wichtigen Themen von der Familienverfassung bis zur Nachfolgeregelung, mit exklusiven Interviews namhafter Unternehmer und nützlichen Best-Practice-Tipps. Ein kompakter Management-Ratgeber!

Two gene loci, which hybridized with pdhA, the structural gene of the E1 component of the Alcaligenes eutrophus pyruvate dehydrogenase complex [Hein, S. & Steinbuchel, A. (1994) J. Bacteriol. 176, 4394–4408], were identified on two nonrelated A. eutrophus chromosomal Bam HI fragments by using a pdhA -specific DNA probe. These data indicated that A. eutrophus possesses, beside PdhA, two additional distinct pyruvate dehydrogenases (E1). A 6.8-kbp genomic Bam HI fragment of A. eutrophus was cloned, and sequence analysis of a 3.896-kbp region revealed the structural gene pdhE (2.694 kbp) for a second pyruvate dehydrogenase (E1), which was not clustered with structural genes for other components of 2-oxo acid dehydrogenase complexes. The A. eutrophus pdhE gene product (898 amino acid residues) exhibited significant similarities to the E1 components of the pyruvate dehydrogenase complexes of A. eutrophus, Neisseria meningitidis, Escherichia coli and Azotobacter vinelandii, which are also composed of only one type of subunit. Heterologous expression of pdhE in the aceEF deletion mutant E. coli YYC202 was demonstrated by spectrometric detection of enzyme activities and by phenotypic complementation to acetate prototrophy. These complementation studies indicated that the E1 component of the A. eutrophus pyruvate dehydrogenase complex can be replaced by a functionally active pdhE gene product.

Nucleotide sequence analysis of a 3.3-kb genomic EcoRI fragment and of relevant subfragments of a genomic 13.2-kb SmaI fragment of Alcaligenes eutrophus, which were identified by using a dihydrolipoamide dehydrogenase-specific DNA probe, revealed the structural genes of the 2-oxoglutarate dehydrogenase complex in a 7.5-kb genomic region. The genes odhA (2850 bp), odhB (1248 bp), and odhL (1422 bp), encoding 2-oxoglutarate dehydrogenase (El), dihydrolipoamide succinyltransferase (E2), and dihydrolipoamide dehydrogenase (E3), respectively, occur co-linearly in one gene cluster downstream of a putative −35 −10 promoter in the order odhA, odhB, and odhL. In comparison to other bacteria, the occurrence of genes for two E3 components for the pyruvate as well as for the 2-oxoglutarate dehydrogenase complexes is unique. Heterologous expression of the A. eutrophus odh genes in E. coli XL1-Blue and in the kgdA mutant Pseudomonas putida JS347 was demonstrated by the occurrence of protein bands in electropherograms, by spectrometric detection of enzyme activities, and by phenotypic complementation, respectively.

Intercontinental trade has led to multiple introductions of invasive pest species at a global scale. Molecular analyses of the structure of populations support the understanding of ecological strategies and evolutionary patterns that promote successful biological invasions. The oriental fruit moth, Grapholita (= Cydia) molesta, is a cosmopolitan and economically destructive pest of stone and pome fruits, expanding its distribution range concomitantly with global climate warming. We used ten newly developed polymorphic microsatellite markers to examine the genetic structure of G. molesta populations in an agricultural ecosystem in the Emilia-Romagna region of northern Italy. Larvae collected in eight sampling sites were assigned to a mosaic of five populations with significant intra-regional structure. Inferred measures of gene flow within populations implicated both active dispersal, and passive dispersal associated with accidental anthropogenic displacements. Small effective population sizes, coupled with high inbreeding levels, highlighted the effect of orchard management practices on the observed patterns of genetic variation within the sampling sites. Isolation by distance did not appear to play a major role at the spatial scale considered. Our results provide new insights into the population genetics and dynamics of an invasive pest species at a regional scale.

1. Anthropogenic land use leads to increasing habitat fragmentation and habitat loss for many species. Exchange of individuals between and recolonisation of habitat patches is essential for the stability and long-term survival of populations in fragmented landscapes. Inter-patch dispersal depends on the dispersal ability of species and on landscape structure. 2. In this study, we analysed the influence of patch size, patch connectivity and sand dynamics on thorax- and wing length as proxies for dispersal ability of the blue-winged grasshopper Oedipoda caerulescens in coastal grey dunes. 3. Our study revealed that sand dynamics and patch configuration had clear though sex-specific effects on dispersal-related morphology. Males were smaller and had shorter wings if patches became larger and less connected. In addition, both sexes were larger in habitat patches with high sand dynamics compared to those in patches with lower dynamics. Investments in wing length were only larger in connected populations when sand dynamics were low, indicating that both landscape and patch-related environmental factors are of importance. 4. The observed effect of landscape characteristics on morphology agrees with predictions from theoretical models on the evolution of dispersal in metapopulations. However, as effects appear to be less pronounced in females, it is possible that selection pressures act differently on both sexes. An alternative explanation, however, would be that the observed patterns could be due to sex-specific phenotypic plasticity. The presented results add to the evidence that dispersal-related morphology varies according to expectations on dispersal evolution in recently structured populations at small spatial scales.

Mutants with defects in components of the glutathione-glutaredoxin (GSH/Grx) system of Rhodobacter capsulatus were constructed to study its role in defense against oxidative stress and the redox-dependent formation of photosynthetic complexes. The lack of the glutaredoxin 3 gene ( grxC ) or the glutathione synthetase B gene ( gshB ) resulted in lower growth rates under aerobic conditions and higher sensitivity to oxidative stress, confirming the role of the GSH/Grx system in oxidative stress defense. Both mutants are highly sensitive to disulfide stress, indicating a major contribution of the GSH/Grx system to the thiol-disulfide redox buffer in the cytoplasm. Like mutations in the thioredoxin system, mutations in the GSH/Grx system affected the formation of photosynthetic complexes, which is redox dependent in R. capsulatus . Expression of the genes grxC , gshB , grxA for glutaredoxin 1, and gorA for glutathione reductase, all encoding components of the GSH/Grx system, was not induced by oxidative stress. Other genes, for which a role in oxidative stress was established in Escherichia coli , acnA , fpr , fur , and katG , were strongly induced by oxidative stress in R. capsulatus . Mutations in the grxC , and/or gshB , and/or trxC (thioredoxin 2) genes affected expression of these genes, indicating an interplay of the different defense systems against oxidative stress. The OxyR and the SoxRS regulons control the expression of many genes involved in oxidative stress defense in E. coli in response to H 2 O 2 and superoxide, respectively. Our data and the available genome sequence of R. capsulatus suggest that a SoxRS system is lacking but an alternative superoxide specific regulator exists in R. capsulatus. While the expression of gorA and grxA is regulated by H 2 O 2 in E. coli this is not the case in R. capsulatus , indicating that the OxyR regulons of these two species are significantly different.

Here we describe a novel microarray platform that integrates all functions needed to perform any array-based experiment in a compact instrument on the researcher's laboratory benchtop. Oligonucle otide probes are synthesized in situ via a light- activated process within the channels of a three-dimensional microfluidic reaction carrier. Arrays can be designed and produced within hours according to the user's requirements. They are processed in a fully automatic workflow. We have characterized this new platform with regard to dynamic range, discrimination power, reproducibility and accuracy of biological results. The instrument detects sample RNAs present at a frequency of 1:100 000. Detection is quantitative over more than two orders of magnitude. Experiments on four identical arrays with 6398 features each revealed a mean coefficient of variation (CV) value of 0.09 for the 6398 unprocessed raw intensities indicating high reproducibility. In a more elaborate experiment targeting 1125 yeast genes from an unbiased selection, a mean CV of 0.11 on the fold change level was found. Analyzing the transcriptional response of yeast to osmotic shock, we found that biological data acquired on our platform are in good agreement with data from Affymetrix GeneChips, quantitative real-time PCR and--albeit somewhat less clearly--to data from spotted cDNA arrays obtained from the literature.

Intensive research on the physiology, biochemistry, and molecular genetics of the metabolism of polyhydroxyalkanoates (PHA) during the last 15 years has revealed a dramatic increase of our knowledge on the biosynthesis of these polyesters in bacteria. This mainly very basic research has revealed several new, hitherto not described enzymes and pathways. In addition, many genes encoding the enzymes of these pathways and in particular the key enzyme of PHA biosynthesis, PHA synthase, were cloned and characterized at a molecular level. This knowledge was utilized to establish PHA biosynthesis in many prokaryotic and eukaryotic organisms, which were unable to synthesize PHAs, and to apply the methodology of metabolic engineering, thus opening new perspectives for the production of various PHAs by fermentation biotechnology or agriculture in economically feasible processes. This contribution summarizes the properties of PHA synthases and gives an overview on the genes for these enzymes and other enzymes of PHA biosynthesis that have been cloned and are available. It also summarizes our current knowledge on the regulation at the enzyme and gene level of PHA biosynthesis in bacteria.

During cultivation under storage conditions with BG11 medium containing acetate as a carbon source, Synechocystis sp. PCC6803 accumulated poly(3-hydroxybutyrate) up to 10% (w/w) of the cell dry weight. Our analysis of the complete Synechocystis sp. PCC6803 genome sequence, which had recently become available, revealed that not only the open reading frame slr1830 (which was designated as phaC) but also the open reading frame slr1829, which is located colinear and upstream of phaC, most probably represent a polyhydroxyalkanoic acid (PHA) synthase gene. The open reading frame slr1829 was therefore designated as phaE. The phaE and phaC gene products exhibited striking sequence similarities to the corresponding PHA synthase subunits PhaE and PhaC of Thiocystis violacea, Chromatium vinosum, and Thiocapsa pfennigii. The Synechocystis sp. PCC6803 genes were cloned using PCR and were heterologously expressed in Escherichia coli and in Alcaligenes eutrophus. Only coexpression of phaE and phaC partially restored the ability to accumulate poly(3-hydroxybutyrate) in the PHA-negative mutant A. eutrophus PHB–4. These results confirmed our hypothesis that coexpression of the two genes is necessary for the synthesis of a functionally active Synechocystis sp. PCC6803 PHA synthase. PHA granules were detected by electron microscopy in these cells, and the PHA-granule-associated proteins were studied. Western blot analysis of Synechocystis sp. PCC6803 crude cellular extracts and of granule-associated proteins employing antibodies raised against the PHA synthases of A. eutrophus (PhaC) and of C. vinosum (PhaE and PhaC) revealed no immunoreaction.

From a genomic library of Alcaligenes eutrophus strain H16 in the broad-host range cosmid pVK100 a 6300-bp EcoRI-fragment was cloned, which restored the wild-type phenotype in transposon-induced poly(3-hydroxybutyric acid)-leaky mutants, derived from A. eutrophus. Nucleotide sequence analysis of the region adjacent to the transposon insertion revealed an open reading frame which complied with all criteria for a coding region. This region was referred to as phbL, and the deduced amino acid sequence from this part of phbL showed 60% amino acid identity in an overlap of 98 residues to the lipoamide dehydrogenase gene (lpd) of Escherichia coli. In addition, the 6300-bp EcoRI-fragment conferred expression of lipoamide dehydrogenase activity to E. coli.