Global aerial flyways allow efficient travelling.

Birds migrate over vast distances at substantial costs. The highly dynamic nature of the air makes the selection of the best travel route difficult. We investigated to what extent migratory birds may optimise migratory route choice with respect to wind, and if route choice can be subject to natural selection. Following the optimal route, calculated using 21 years of empirical global wind data, reduced median travel time by 26.5% compared to the spatially shortest route. When we used a time-dependent survival model to quantify the adaptive benefit of choosing a fixed wind-optimised route, 84.8% of pairs of locations yielded a route with a higher survival than the shortest route. This suggests that birds, even if incapable of predicting wind individually, could adjust their migratory routes at a population level. As a consequence, this may result in the emergence of low-cost flyways representing a global network of aerial migratory pathways.

Resistance to pyrethroid insecticides in Helicoverpa zea (Lepidoptera: Noctuidae) in Indiana and Illinois.

The corn earworm, Helicoverpa zea (Boddie) (Lepidoptera: Noctuidae), can cause serious losses in many field and vegetable crops throughout the United States. Since their introduction, pyrethroid insecticides have become the primary insecticide class for managing H. zea. However, resistance has been reported in the southern United States and has recently became a concern in the Midwest after the observation of sporadic control failures and a decreased efficacy of pyrethroids in small-plot field trials. Larvae collected from Lafayette, IN, Vincennes, IN, and Collinsville, IL, were used to establish laboratory colonies in 2006 and 2007. Larvae from these colonies were tested for resistance to the pyrethroid insecticide bifenthrin by using topical assays. Adult males collected from pheromone traps in Lafayette were tested for resistance to cypermethrin by using the adult vial test (AVT) method. Resistance ratios of > or =8 were observed for the larvalbifenthrin assays in 2006 and 2007 in all colonies except for the 2007 Illinois colony. AVT assays conducted with cypermethrin showed approximately 15% survival in both 2006 and 2007 at the 5 microg per vial discriminating dose. These results suggest that low to moderate levels of pyrethroid resistance are present in these populations.

Population densities of corn flea beetle (Coleoptera: Chrysomelidae) and incidence of Stewart's wilt in sweet corn.

To quantify populations of the corn flea beetle, Chaetocnema pulicaria Melsheimer (Coleoptera: Chrysomelidae), and refine estimates of a threshold for its control to prevent Stewart's wilt caused by Erwinia stewartii, sequential plantings of 'Jubilee' sweet corn were made at 2-wk intervals from April or May through August or September 2001 and 2002 at four locations from southern to northern Illinois: Simpson, Brownstown, Champaign, and Mendota. Densities of C. pulicaria and incidence of Stewart's wilt were monitored weekly. At Mendota, where C. pulicaria populations were decimated by cold temperatures during winter 2000-2001, densities reached 33.3 beetles per 15-cm yellow sticky trap per day by September 2002, after a mild 2001-2002 winter. Maximum incidence of Stewart's wilt in single plots at Simpson, Brownstown, Champaign, and Mendota was 22, 36, 39, and 2%, respectively, in 2001, and 33, 47, 99, and 87%, respectively, in 2002. In 24 plots where beetle densities were < or =2 per trap per day, Stewart's wilt incidence was <5% in 20 plots. We propose that two corn flea beetles per trap per day be used as a threshold for insecticide application to seedlings to control C. pulicaria and minimize subsequent incidence of Stewart's wilt in processing sweet corn. Enzyme-linked immunosorbent assays indicated that E. stewartii incidence in C. pulicaria peaked at 67, 62, and 54%, respectively, at Simpson, Brownstown, and Champaign, in 2001, and at 71, 76, and 60%, respectively, in 2002. Further studies might allow the use of areawide or field-specific estimates of E. stewartii incidence in corn flea beetles for adjusting management decisions.

Structure of an archaeal homolog of the eukaryotic RNA polymerase II RPB4/RPB7 complex.

The eukaryotic subunits RPB4 and RPB7 form a heterodimer that reversibly associates with the RNA polymerase II core and constitute the only two components of the enzyme for which no structural information is available. We have determined the crystal structure of the complex between the Methanococcus jannaschii subunits E and F, the archaeal homologs of RPB7 and RPB4. Subunit E has an elongated two-domain structure and contains two potential RNA binding motifs, while the smaller F subunit wraps around one side of subunit E, at the interface between the two domains. We propose a model for the interaction between RPB4/RPB7 and the core RNA polymerase in which the RNA binding face of RPB7 is positioned to interact with the nascent RNA transcript.

Interactions between Nosema pyrausta (Microsporidia: Nosematidae) and Bacillus thuringiensis subsp. kurstaki in the European corn borer (Lepidoptera: Pyralidae).

Larval susceptibility to Bacillus thuringiensis was determined for Nosema pyrausta-infected and uninfected European corn borers, Ostrinia nubilalis (Hübner), in bioassays using a commercial formulation of B. thuringiensis subsp. kurstaki, Dipel ES, incorporated into diet. LC50 values for N. pyrausta-infected larvae were significantly lower (P<0.0001) than for uninfected larvae and declined with increasing levels of infection. LC50 values for a 15-d bioassay using field-colony first instars were 0.006 and 0.027 mg of Dipel ES/kg of diet for larvae moderately infected by N. pyrausta and uninfected larvae, respectively. Nosema pyrausta-infected larvae reared on Dipel ES-amended diets produced 70-fold fewer spores (P<0.0001) than larvae reared on standard diet. For example, 15 d after placement as first instars on standard diet, infected field-colony larvae produced 7.6-8.7 million N. pyrausta spores per larva; similar larvae placed on diet containing 0.09 mg of Dipel ES/kg of diet produced 85-103 thousand spores per larva. Infected larvae also weighed less and failed to mature on Dipel ES-amended diets. Increased susceptibility of N. pyrausta-infected larvae to Dipel ES and reduced N. pyrausta spore production in larvae feeding on diet containing Dipel ES suggest that Bt corn will have a direct adverse effect on the survival and continual impact of N, pyrausta as a regulating factor on European corn borer populations.

Archaeal RNA polymerase subunits F and P are bona fide homologs of eukaryotic RPB4 and RPB12.

The archaeal and eukaryotic evolutionary domains diverged from each other approximately 2 billion years ago, but many of the core components of their transcriptional and translational machineries still display a readily recognizable degree of similarity in their primary structures. The F and P subunits present in archaeal RNA polymerases were only recently identified in a purified archaeal RNA polymerase preparation and, on the basis of localized sequence homologies, tentatively identified as archaeal versions of the eukaryotic RPB4 and RPB12 RNA polymerase subunits, respectively. We prepared recombinant versions of the F and P subunits from Methanococcus jannaschii and used them in in vitro and in vivo protein interaction assays to demonstrate that they interact with other archaeal subunits in a manner predicted from their eukaryotic counterparts. The overall structural conservation of the M. jannaschii F subunit, although not readily recognizable on the primary amino acid sequence level, is sufficiently high to allow the formation of an archaeal-human F-RPB7 hybrid complex.

Crystal structure of RPB5, a universal eukaryotic RNA polymerase subunit and transcription factor interaction target.

Eukaryotic nuclei contain three different types of RNA polymerases (RNAPs), each consisting of 12-18 different subunits. The evolutionarily highly conserved RNAP subunit RPB5 is shared by all three enzymes and therefore represents a key structural/functional component of all eukaryotic RNAPs. Here we present the crystal structure of the RPB5 subunit from Saccharomyces cerevisiae. The bipartite structure includes a eukaryote-specific N-terminal domain and a C-terminal domain resembling the archaeal RNAP subunit H. RPB5 has been implicated in direct protein-protein contacts with transcription factor IIB, one of the components of the RNAP(II) basal transcriptional machinery, and gene-specific activator proteins, such as the hepatitis B virus transactivator protein X. The experimentally mapped regions of RPB5 involved in these interactions correspond to distinct and surface-exposed alpha-helical structures.

Control of Stewart's Wilt in Sweet Corn with Seed Treatment Insecticides.

Corn flea beetles, Chaetocnema pulicaria, vector Erwinia stewartii (synamorph Pantoea stewartii), which causes Stewart's bacterial wilt of corn (Zea mays). A seed treatment insecticide, imidacloprid, killed flea beetles and reduced the number of feeding wounds and Stewart's wilt symptoms per leaf in greenhouse studies. The objective of our research was to evaluate the ability of imidacloprid and thiamethoxam seed treatments to control Stewart's wilt on sweet corn hybrids under field conditions with naturally occurring populations of the corn flea beetle. Six field trials were planted at four locations in 1998. Eleven field trials were planted at nine locations in 1999. The treatment design was a factorial of sweet corn hybrids and seed treatments. Stewart's wilt incidence ranged from 0 to 54% in the 1998 trials. Incidence of Stewart's wilt in nontreated plots of the susceptible hybrid Jubilee ranged from 2% at the 8-leaf stage to 77% 1 week after mid-silk in the 1999 trials. Seed treatment insecticides reduced the incidence of Stewart's wilt by ≈50 to 85% relative to nontreated controls. The level of control was ≈75 to 85% in seven trials planted before 1 June 1999, when incidence of Stewart's wilt on nontreated Jubilee ranged from 4 to 71%. The level of control was ≈50 to 70% in the three trials planted after 1 July 1999, when incidence of Stewart's wilt on nontreated Jubilee ranged from 44 to 73%. Although comparisons varied, the level of control gained from seed treatment insecticides was similar to the next higher level of host resistance. Seed treatment insecticides appear to control Stewart's wilt during very early growth of corn plants, when foliar applications of insecticides are ineffective and the effectiveness of host resistance varies depending on the proximity of flea beetle feeding sites to the plant's growing point.

Solanaceous Weeds as Possible Sources of Cucumber mosaic virus in Southern Illinois for Aphid Transmission to Pepper.

Over 5,000 individual plants representing approximately 55 species from an area in southern Illinois where Cucumber mosaic virus (CMV) has been a major problem in pepper (Capsicum annuum) were tested for the presence of CMV by enzyme-linked immunosorbent assay (ELISA). Representative ELISA-positive samples were checked by western blot tests to confirm virus-specific reactions. Nearly all of the infected plants detected were either Solanum ptycanthum (eastern black nightshade) or Physalis spp. (principally P. heterophylla, groundcherry). Over 1,000 pepper transplants and approximately 500 tomato transplants, collected prior to planting, were negative for CMV by ELISA. In aphid transmission (arena) experiments, all five aphid species tested were capable of transmitting CMV from nightshade to pepper: Aphis fabae subsp. solanella, Aphis gossypii, Myzus persicae, Rhopalosiphum padi, and Sitobion avenae. Aphis fabae subsp. solanella, A. gossypii, and A. nerii were able to transmit CMV from P. heterophylla to pepper. Aphis fabae subsp. solanella was commonly found colonizing nightshade from May through October in southern Illinois.

Crystallization and preliminary diffraction studies of the RNA polymerase subunit RPB5 from Saccharomyces cerevisiae.

Crystals of the RNA polymerase subunit RPB5 from Saccharomyces cerevisiae have been obtained by vapour-diffusion techniques. The protein has been overexpressed in bacterial cells as a fusion with glutathione S-transferase. Two monoclinic crystal forms can be grown under different sets of conditions. In both cases, the diffraction is consistent with space group P21, with unit-cell parameters a = 45. 3, b = 135.3, c = 47.3 A, beta = 118.6 degrees for crystal form I and a = 48.4, b = 137.1, c = 47.1 A, beta = 118.6 degrees for crystal form II.

RNA polymerase subunit H features a beta-ribbon motif within a novel fold that is present in archaea and eukaryotes.

The archaeal H and eukaryotic RPB5 RNA polymerase subunits are highly homologous and are likely to play a fundamental role in transcription that extends from archaea to humans. We report the structure of subunit H, in solution, from the archaeon Methanococcus jannaschii using multidimensional nuclear magnetic resonance. The structure reveals a novel fold containing a four-stranded mixed beta sheet that is flanked on one side by three short helices. The dominant feature is beta-ribbon motif, which presents a hydrophobic, basic surface, and defines a general RNA polymerase architectural scaffold.

In vitro assembly of an archaeal D-L-N RNA polymerase subunit complex reveals a eukaryote-like structural arrangement.

Archaeal RNA polymerases (RNAPs) resemble the eukaryotic nuclear RNAPs in complexity, and many of their subunits display a high degree of sequence similarity to their eukaryotic counterparts. Here we describe specific protein-protein contacts present between individual recombinant RNAP subunits from the archaeon Methanococcus jannaschii. Subunits D and L interact specifically with each other in two-hybrid assays. D also interacts under the same conditions with the RPB11 and AC19 subunits from the yeast Saccharomyces cerevisiae, suggesting that essential elements of the binding surface between these proteins have been conserved across the archaeal/eukaryotic evolutionary domain boundary. Interactions between L and RPB3 or AC40 were, however, not detectable. Recombinant D and L subunits associate under in vitro conditions and copurify with each other during size-exclusion chromatography. Addition of an another recombinant subunit (N) to the D-L complex results in the formation of a triple complex. This D-L-N complex resembles the RPB3-RPB11-RPB10 or AC40-AC19-RPB10 complexes in eukaryotic RNAPIIand RNAPI/RNAPIII, respectively. Our data provide evidence for a close similarity in the quaternary arrangement of a subset of archaeal and eukaryotic RNA polymerase subunits and the conservation of the protein-protein contacts formed between them.

Releases of Spalangia nigroaenea and Muscidifurax zaraptor (Hymenoptera: Pteromalidae) increase rates of parasitism and total mortality of stable fly and house fly (Diptera: Muscidae) pupae in Illinois cattle feedlots.

Weekly releases of Spalangia nigroaenea Curtis and Muscidifurax zaraptor Kogan & Legner from May through August of 1991-1993 at small, owner-operated cattle feedlots in Illinois provided weekly emergence of 100-300 parasitoids of each species per feedlot animal. In assessments based on fly and parasitoid emergence from > 47,000 stable fly and house fly puparia collected during the 3-yr period, total stable fly mortality was greater in lots where releases were made (60.7%) than in paired, untreated control lots (51.7%) (P = 0.04; paired t-test); parasitism of stable fly pupae by S. nigroaenea averaged 11.6% where releases were made and 6.4% in paired control lots (P = 0.0016). In lots where releases were made, total mortality of house fly pupae was greater (68.7 versus 56.1%; P = 0.0001); unexplained mortality was greater (55.5 versus 46.1%; P = 0.0018); and parasitism by Muscidifurax spp. was greater (2.4 versus 1.4%; P = 0.07) than in paired control lots. Parasitism, unexplained mortality, and total mortality of both fly species varied significantly from 1991 to 1992 in lots that received the same treatment each year, presumably due primarily to weather. Over the 3-yr period, releasing these species, particularly S. nigroaenea, significantly reduced production of stable fly and house fly adults in cattle feedlots. The potential value of such reductions is likely to vary as a result of feedlot conditions and weather.

Eukaryotic RNA polymerase subunit RPB8 is a new relative of the OB family.

RNA polymerase II subunit RPB8 is an essential subunit that is highly conserved throughout eukaryotic evolution and is present in all three types of nuclear RNA polymerases. We report the first high resolution structural insight into eukaryotic RNA polymerase architecture with the solution structure of RPB8 from Saccharomyces cerevisiae. It consists of an eight stranded, antiparallel beta-barrel, four short helical regions and a large, unstructured omega-loop. The strands are connected in classic Greek-key fashion. The overall topology is unusual and contains a striking C2 rotational symmetry. Furthermore, it is most likely a novel associate of the oligonucleotide/oligosaccharide (OB) binding protein class.

Homeotic gene expression in the locust Schistocerca: an antibody that detects conserved epitopes in Ultrabithorax and abdominal-A proteins.

To investigate what role homeotic genes may play in morphological evolution, we are comparing homeotic gene expression in two very different insects, Drosophila (Diptera) and Schistocerca (Orthoptera). In this paper we describe a monoclonal antibody, FP6.87, that recognizes the products of both the Ultrabithorax (Ubx) and abdominal-A (abd-A) genes in Drosophila, via an epitope common to the carboxy terminal region of these two proteins. This antibody recognizes nuclear antigens present in the posterior thorax and abdomen of Schistocerca. We infer that it recognizes the Schistocerca homolog of UBX protein, and probably also of ABD-A. As the distribution of Schistocerca ABD-A protein is already known, we can use this reagent to map the expression of Schistocerca UBX in the thorax and anterior abdomen, where ABD-A is not expressed. Both the general domain, and many of the details, of UBX expression are remarkably conserved compared with Drosophila. Thus UBX expression extends back from T2 in the ectoderm (including the CNS), but only from A1 in the mesoderm. As noted for other bithorax complex genes in Schistocerca, expression begins in the abdomen, at or shortly before the time of segmentation. It only later spreads anteriorly to the thorax. For much of embryogenesis, the expression of UBX in the thoracic epidermis is largely restricted to the T3 limb. In this limb, UBX is strikingly regulated, in a complex pattern that reflects limb segmentation. Reviewing these and earlier observations, we conclude that evolutionary changes affect both the precise regulation of homeotic genes within segments, and probably also the spectrum of downstream genes that respond to homeotic gene expression in a given tissue. Overall domains of homeotic gene expression appear to be well conserved between different insect groups, though a change in the extent and timing of homeotic gene expression may underlie the modification of the posterior abdomen in different insect groups.

[The "Freiburg Migraine Study". Results of the psychological therapy.]. / Die "Freiburger Migränestudie" : Ergebnisse der psychologischen Therapie.

UNLABELLED: This study was designed to evaluate the efficacy of different strategies for migraine prophylaxis over a fairly long period. Metoprolol alone was compared with psychotherapy alone and with a combination of metoprolol and psychotherapy. The psychological programme was planned for future use in preventive treatment. In this paper only the results of the psychological therapy are described. PATIENTS AND METHODS: Criteria for inclusion of patients were: migraine without aura or with short aura for at least 2 years, and 2-10 attacks per month. In all, 63 patients (11 men and 52 women) were each randomized for participation one of the three kinds of treatment. All patients declared their willingness to participate in all three different therapies. After neurological and psychological diagnosis the baseline phase of 2 months was started, followed by the intensive therapy phase lasting 3 months. The end of the intensive therapy is followed by a first 2-month follow-up period. A second follow-up of 2 months was started 6 months after the end of intensive therapy. Psychological diagnosis involved the following elements: a migraine questionnaire, a list of patient's complaints, a depression scale and a psychological exploration. All patients kept a diary during all phases of the study with daily descriptions of their headaches, the therapy and their mood. The psychological programme lasted for 12 sessions of 2 hours each. A psychologist worked with small groups of up to 5 patients This programme was composed of progressive relaxation techniques (Jacobson) and techniques aimed at overcoming pain and stress. The data on diagnosis, the baseline phase, the intensive therapy phase and the two follow-up phases were analysed by conventional statistics (comparison of mean values,t-test, variance analysis, non-parametric tests) and by time series analysis. The parameters analysed were: frequency of attacks, mean headache intensity, duration of headache and migraine, consumption of analgesic drugs and mood. Analysis of the questionnaires and the different diagnostic data revealed no significant differences between the three different groups of therapy. RESULTS: A significant improvement in one or at least two measured parameters is shown in Table 1. The results, with 62.5% responders for one parameter in the first follow-up phase are rather positive. If two variables are required to improve significantly the results become worse. Over the different phases the results improve slightly, probably due to the effect of training. In the time series analysis the percentage of responders was calculated to show the number of responders for a particular variable (Table 3). For the different parameters the percentage of responders varied between 0 and 31.3%. CONCLUSIONS: According to the results, the efficacy of the psychological treatment increases only gradually, as it has also been demonstrated for biofeedback and relaxation training [9]. Subjectively, patients rate the results of psychotherapy higher than those demonstrated by statistics. This may depend on the selection of patients, but also on the fact that subjective criteria of improvement are not contained in statistical evaluation. Responders and non-responders had initial differences regarding vegetative, hormonal and psychological factors. Responders had a more stable circulatory status, suffered more rarely from menstrual migraine and normally took significantly fewer analgesic drugs. On the whole, this psychological programme has proved quite effective.

Cloning and expression of Drosophila TAFII60 and human TAFII70 reveal conserved interactions with other subunits of TFIID.

Regulation of transcription initiation by RNA polymerase II requires TFIID, a multisubunit complex composed of the TATA binding protein (TBP) and at least seven tightly associated factors (TAFs). Some TAFs act as direct targets or coactivators for promoter-specific activators while others serve as interfaces for TAF-TAF interactions. Here, we report the molecular cloning, expression and characterization of Drosophila dTAFII60 and its human homolog, hTAFII70. Recombinant TAFII60/70 binds weakly to TBP and tightly to the largest subunit of TFIID, TAFII250. In the presence of TAFII60/70, TBP and TAFII250, a stable ternary complex is formed. Both the human and Drosophila proteins directly interact with another TFIID subunit, dTAFII40. Our findings reveal that Drosophila TAFII60 and human TAFII70 share a high degree of structural similarity and that their interactions with other subunits of TFIID are conserved.

The dTAFII80 subunit of Drosophila TFIID contains beta-transducin repeats.

A key component of the RNA polymerase II transcriptional apparatus, TFIID, is a multi-protein complex containing the TATA box-binding protein (TBP) and at least seven tightly associated factors (TAFs). Although the functions of most TFIID subunits are unknown, it is clear that TAFs are not necessary for basal activity but that one or more are required for regulated transcription, and so behave as coactivators. The presence of multiple subunits indicates that there is an intricate assembly process and that TAFs may be responsible for other activities. We have described the properties of the subunit dTAFII110, which can interact directly with the transcriptional activator Sp1 (ref. 5). In addition, the largest subunit, dTAFII250, binds directly to TBP and links other TAFs to the complex. Here we describe the cloning, expression and partial characterization of the Drosophila TAF of M(r) 80,000, dTAFII80. Sequence analysis reveals that dTAFII80 contains several copies of the WD40 (beta-transducin) repeat. Moreover, dTAFII80 shares extended sequence similarity with an Arabidopsis gene, COP1, which encodes a putative transcription factor that is though to regulate development. We have expressed recombinant dTAFII80 and begun to characterize its interaction with other members of the TFIID complex. Purified recombinant dTAFII80 is unable to bind TBP directly or to interact strongly with the C-terminal domain of dTAFII250 (delta N250). Instead, dTAFII80 is only able to recognize and interact with a higher-order complex containing TBP, delta N250, 110 and 60. These findings suggest the formation of TFIID may require an ordered assembly of the TAFs, some of which bind directly to TBP and others that are tethered to the complex as a result of specific TAF/TAF interactions.

Largest subunit of Drosophila transcription factor IID directs assembly of a complex containing TBP and a coactivator.

The TFIID complex consists of the TATA-binding protein (TBP) and associated factors (TAFs) serving to mediate transcriptional activation by promoter-specific regulators. Here we report the cloning of Drosophila TAFII250 and the assembly of a partial complex containing recombinant TBP, TAFII110 and the C-terminal domain of TAFII250. This triple complex supports Sp1 activation and reveals specific interactions between TAFII250, TBP and TAFII110.

Molecular cloning and functional analysis of Drosophila TAF110 reveal properties expected of coactivators.

The general transcription factor TFIID is a multiprotein complex containing the TATA-binding protein and several associated factors (TAFs), some of which may function as coactivators that are essential for activated, but not basal, transcription. Here we describe the isolation and characterization of the first gene encoding a TAF protein. The deduced amino acid sequence of TAF110 revealed the presence of several glutamine- and serine/threonine-rich regions reminiscent of the protein-protein interaction domains of the regulatory transcription factor Sp1 that are involved in transcription activation and multimerization. In both Drosophila cells and yeast, TAF110 specifically interacts with the glutamine-rich activation domains of Sp1. Moreover, purified Sp1 selectively binds recombinant TAF110 in vitro. These findings taken together suggest that TAF110 may function as a coactivator by serving as a site of protein-protein contact between activators like Sp1 and the TFIID complex.