Relative Effects of Juvenile and Adult Environmental Factors on Mate Attraction and Recognition in the Cricket, Allonemobius socius

Finding a mate is a fundamental aspect of sexual reproduction. To this end, specific-mate recognition systems (SMRS) have evolved that facilitate copulation between producers of the mating signal and their opposite-sex responders. Environmental variation, however, may compromise the efficiency with which SMRS operate. In this study, the degree to which seasonal climate experienced during juvenile and adult life-cycle stages affects the SMRS of a cricket, Allonemobius socius (Scudder) (Orthoptera: Gryllidae) was assessed. Results from two-choice behavioral trials suggest that adult ambient temperature, along with population and family origins, mediate variation in male mating call, and to a lesser extent directional response of females for those calls. Restricted maximum-likelihood estimates of heritability for male mating call components and for female response to mating call appeared statistically nonsignificant. However, appreciable “maternal genetic effects” suggest that maternal egg provisioning and other indirect maternal determinants of the embryonic environment significantly contributed to variation in male mating call and female response to mating calls. Thus, environmental factors can generate substantial variation in A. socius mating call, and, more importantly, their marginal effect on female responses to either fast-chirp or long-chirp mating calls suggest negative fitness consequences to males producing alternative types of calls. Future studies of sexual selection and SMRS evolution, particularly those focused on hybrid zone dynamics, should take explicit account of the loose concordance between signal producers and responders suggested by the current findings

Rmi1 stimulates decatenation of double Holliday junctions during dissolution by Sgs1-Top3

double Holliday junction (dHJ) is a central intermediate of homologous recombination that can be processed to yield crossover or non-crossover recombination products. To preserve genomic integrity, cells possess mechanisms to avoid crossing over. We show that Saccharomyces cerevisiae Sgs1 and Top3 proteins are sufficient to migrate and disentangle a dHJ to produce exclusively non-crossover recombination products, in a reaction termed "dissolution." We show that Rmi1 stimulates dHJ dissolution at low Sgs1-Top3 protein concentrations, although it has no effect on the initial rate of Holliday junction (HJ) migration. Rmi1 serves to stimulate DNA decatenation, removing the last linkages between the repaired and template DNA molecules. Dissolution of a dHJ is a highly efficient and concerted alternative to nucleolytic resolution that prevents crossing over of chromosomes during recombinational DNA repair in mitotic cells and thereby contributes to genomic integrity

The Generation of Successive Unmarked Mutations and Chromosomal Insertion of Heterologous Genes in Actinobacillus pleuropneumoniae Using Natural Transformation

We have developed a simple method of generating scarless, unmarked mutations in Actinobacillus pleuropneumoniae by exploiting the ability of this bacterium to undergo natural transformation, and with no need to introduce plasmids encoding recombinases or resolvases. This method involves two successive rounds of natural transformation using linear DNA: the first introduces a cassette carrying cat (which allows selection by chloramphenicol) and sacB (which allows counter-selection using sucrose) flanked by sequences to either side of the target gene; the second transformation utilises the flanking sequences ligated directly to each other in order to remove the cat-sacB cassette. In order to ensure efficient uptake of the target DNA during transformation, A. pleuropneumoniae uptake sequences are added into the constructs used in both rounds of transformation. This method can be used to generate multiple successive deletions and can also be used to introduce targeted point mutations or insertions of heterologous genes into the A. pleuropneumoniae chromosome for development of live attenuated vaccine strains. So far, we have applied this method to highly transformable isolates of serovars 8 (MIDG2331), which is the most prevalent in the UK, and 15 (HS143). By screening clinical isolates of other serovars, it should be possible to identify other amenable strains

Cysteine oxidation targets peroxiredoxins 1 and 2 for exosomal release through a novel mechanism of redox-dependent secretion

Non-classical protein secretion is of major importance as a number of cytokines and inflammatory mediators are secreted via this route. Current evidence indicates that there are several mechanistically distinct methods of non-classical secretion. We have recently shown that peroxiredoxin (Prdx) 1 and Prdx2 are released by various cells upon exposure to inflammatory stimuli such as LPS or TNF-α. The released Prdx then acts to induce production of inflammatory cytokines. However, Prdx1 and 2 do not have signal peptides and therefore must be secreted by alternative mechanisms as has been postulated for the inflammatory mediators IL-1β and HMGB1. We show here that circulating Prdx1 and 2 are present exclusively as disulphide-linked homodimers. Inflammatory stimuli also induce in vitro release of Prdx1 and 2 as disulfide-linked homodimers. Mutation of cysteines Cys51 or Cys172 (but not Cys70) in Prdx2, and Cys52 or Cys173 (but not Cys71 or Cys83) in Prdx1 prevented dimer formation and this was associated with inhibition of their TNF-α-induced release. Thus, the presence and oxidation of key cysteine residues in these proteins are a prerequisite for their secretion in response to TNF-α and this release can be induced with an oxidant. In contrast, the secretion of the nuclear-associated danger signal HMGB1 is independent of cysteine oxidation, as shown by experiments with a cysteine-free HMGB1 mutant. Release of Prdx1 and 2 is not prevented by inhibitors of the classical secretory pathway; instead, both Prdx1 and 2 are released in exosomes from both HEK cells and monocytic cells. Serum Prdx1 and 2 are also associated with the exosomes. These results describe a novel pathway of protein secretion mediated by cysteine oxidation that underlines the importance of redox-dependent signalling mechanisms in inflammation

Positive Interspecific Relationship between Temporal Occurrence and Abundance in Insects

One of the most studied macroecological patterns is the interspecific abundance–occupancy relationship, which relates species distribution and abundance across space. Interspecific relationships between temporal distribution and abundance, however, remain largely unexplored. Using data for a natural assemblage of tabanid flies measured daily during spring and summer in Nova Scotia, we found that temporal occurrence (proportion of sampling dates in which a species occurred in an experimental trap) was positively related to temporal mean abundance (number of individuals collected for a species during the study period divided by the total number of sampling dates). Moreover, two models that often describe spatial abundance–occupancy relationships well, the He–Gaston and negative binomial models, explained a high amount of the variation in our temporal data. As for the spatial abundance–occupancy relationship, the (temporal) aggregation parameter, k, emerged as an important component of the hereby named interspecific temporal abundance–occurrence relationship. This may be another case in which a macroecological pattern shows similarities across space and time, and it deserves further research because it may improve our ability to forecast colonization dynamics and biological impacts

Gene therapy for carcinoma of the breast: Genetic toxins

Gene therapy was initially envisaged as a potential treatment for genetically inherited, monogenic disorders. The applications of gene therapy have now become wider, however, and include cardiovascular diseases, vaccination and cancers in which conventional therapies have failed. With regard to oncology, various gene therapy approaches have been developed. Among them, the use of genetic toxins to kill cancer cells selectively is emerging. Two different types of genetic toxins have been developed so far: the metabolic toxins and the dominant-negative class of toxins. This review describes these two different approaches, and discusses their potential applications in cancer gene therapy

Exploring the structure of the N-terminal domain of CP29 with ultrafast fluorescence spectroscopy

A high-throughput Förster resonance energy transfer (FRET) study was performed on the approximately 100 amino acids long N-terminal domain of the photosynthetic complex CP29 of higher plants. For this purpose, CP29 was singly mutated along its N-terminal domain, replacing one-by-one native amino acids by a cysteine, which was labeled with a BODIPY fluorescent probe, and reconstituted with the natural pigments of CP9, chlorophylls and xanthophylls. Picosecond fluorescence experiments revealed rapid energy transfer (~20–70 ps) from BODIPY at amino-acid positions 4, 22, 33, 40, 56, 65, 74, 90, and 97 to Chl a molecules in the hydrophobic part of the protein. From the energy transfer times, distances were estimated between label and chlorophyll molecules, using the Förster equation. When the label was attached to amino acids 4, 56, and 97, it was found to be located very close to the protein core (~15 Å), whereas labels at positions 15, 22, 33, 40, 65, 74, and 90 were found at somewhat larger distances. It is concluded that the entire N-terminal domain is in close contact with the hydrophobic core and that there is no loop sticking out into the stroma. Most of the results support a recently proposed topological model for the N-terminus of CP29, which was based on electron-spin-resonance measurements on spin-labeled CP29 with and without its natural pigment content. The present results lead to a slight refinement of that model

Successful treatment of Candida parapsilosis mural endocarditis with combined caspofungin and voriconazole

BACKGROUND: Fungal mural endocarditis is a rare entity in which the antemortem diagnosis is seldom made. Seven cases of mural endocarditis caused by Candida spp. have been collected from literature and six of these patients died after treatment with amphotericin B. CASE PRESENTATION: We report a case of mural endocarditis diagnosed by transesophageal echocardiogram and positive blood cultures to Candida parapsilosis. Because blood cultures continued to yield C. parapsilosis despite caspofungin monotherapy, treatment with voriconazole was added. CONCLUSION: This is the first description of successful treatment of C. parapsilosis mural endocarditis with caspofungin and voriconazole

Effectiveness of second generation antipsychotics: A systematic review of randomized trials

<p>Abstract</p> <p>Background</p> <p>Systematic reviews based on efficacy trials are inconclusive about which second generation antipsychotic drug (SGA) should be preferred in normal clinical practice, and studies with longer duration and more pragmatic designs are called for. Effectiveness studies, also known as naturalistic, pragmatic, practical or real life studies, adhere to these principles as they aim to mimic daily clinical practice and have longer follow-up.</p> <p>Objective</p> <p>To review the head-to-head effectiveness of SGAs in the domains of global outcomes, symptoms of disease, and tolerability.</p> <p>Methods</p> <p>Searches were made in Embase, PubMED, and the Cochrane central register of controlled trials for effectiveness studies published from 1980 to 2008, week 1. Different combinations of the keywords <it>antipsychotic*, neuroleptic* AND open, pragmatic, practical, naturalistic, real life, effectiveness, side effect*, unwanted effect*, tolera* AND compar* AND random* </it>were used.</p> <p>Results</p> <p>Sixteen different reports of randomized head-to-head comparisons of SGA effectiveness were located. There were differences regarding sample sizes, inclusion criteria and follow-up periods, as well as sources of financial sponsorship. In acute-phase and first-episode patients no differences between the SGAs were disclosed regarding alleviating symptoms of disease. Olanzapine was associated with more weight gain and adverse effects on serum lipids. In the chronic phase patients olanzapine groups had longer time to discontinuation of treatment and better treatment adherence compared to other SGAs. The majority of studies found no differences between the SGAs in alleviating symptoms of psychosis in chronically ill patients. Olanzapine was associated with more metabolic adverse effects compared to the others SGAs. There were surprisingly few between-drug differences regarding side effects. First generation antipsychotics were associated with lower total mental health care costs in 2 of 3 studies on chronically ill patients, but were also associated with more extrapyramidal side effects compared to the SGAs in several studies.</p> <p>Conclusion</p> <p>In chronically ill patients olanzapine may have an advantage over other SGAs regarding longer time to treatment discontinuation and better drug adherence, but the drug is also associated with more metabolic side effects. More effectiveness studies on first-episode psychosis are needed.</p