Life history,diagnosis, and biological aspects of Engytatus varians (Hemiptera: Miridae), a predator of Bactericera cockerelli (Hemiptera: Triozidae)

The life cycle and several life parameters of the zoophytophagous predator Engytatus varians (Distant) (Heteroptera: Miridae), including nymphal growth according to Dyar’s rule, were examined in the laboratory. The egg, nymph (five instars), and adult stages were 9.20, 17.36, and 19.02?d in length, respectively. The growth ratio for nymphs was consistent with Dyar’s rule based on the lengths of the femora of the forelegs, the tibiae and femora of the middle legs, and the antennae. Some biological characteristics of E. varians were also evaluated when the mirid was fed three different diets (B. cockerelli third instars, Sitotroga cerealella Olivier [Lepidoptera: Gelechiidae] eggs, and a mixture of both instars and eggs). The length of the nymphal stage was three days longer on a diet of only S. cerealella eggs than when the mirids were fed the third instars of B. cockerelli only or a mixture of both. The sex ratio was not affected by the type of diet. Nymphs of E. varians consumed B. cockerelli nymphs (80–85) when fed third instars only and third instars?+?S. cerealella eggs, respectively. The potential use of this predator as a biological control agent of B. cockerelli is discussed.     

El carcinoma diferenciado incidental de tiroides es menos prevalente en la enfermedad de Graves que en el bocio multinodular

ObjectiveRisk factors for differentiated thyroid carcinoma (DTC) are poorly understood, but serum TSH levels, thyroid nodularity, and presence of autoimmunity are well-recognized factors that modulate DTC prevalence. TSH stimulates proliferation of both normal and neoplastic follicular cells. Consequently, thyroid-stimulating immunoglobulins (TSI), because of its TSH-like action, should induce DTC progression in patients with Graves’ disease (GD). The study objective was to compare the prevalence of incidental DTC in patients undergoing thyroidectomy for benign thyroid disease.MethodsThe pathology reports of 372 patients with preoperative diagnosis of euthyroid multinodular goiter (EMG) or hyperthyroidism were reviewed. Scintigraphy results and serum TSI levels were used to diagnosed either GD or hyperactive MG (HMG) to hyperthyroid subjects. Prevalence of DTC in each category was calculated using a Chi-square test.ResultsEMG, GD, and HMG were diagnosed in 221, 125, and 26 patients. There were 58 DTCs, distributed as follows [n (%)]: EMG, 49 (22.2%); GD, 8 (6.4%), and HMG, 1 (3.8%). Difference in prevalence of incidental DTC between the groups was statistically significant (p < 0.001). After adjustment for age, patients with EMG had a greater DTC prevalence than GD patients, with an OR of 4.17 (p < 0.001). Tumor size (mm, mean ± SD) was 6.92 ± 11.26, 1.97 ± 1.85, and 9.0 for EMG, GD and HMG respectively (p = 0.017).ConclusionsIncidental DTC was less prevalent in GD as compared to EMG irrespective of age. This finding may suggest a predisposition to develop DTC in patients with thyroid nodular disease and/or a potential effect of autoimmunity to protect against development of neoplastic disease.     

Obesity and metabolic dysfunction severely influence prostate cell function: role of insulin and IGF1

Obesity is a major health problem that courses with severe comorbidities and a drastic impairment of homeostasis and function of several organs, including the prostate gland (PG). The endocrine–metabolic regulatory axis comprising growth hormone (GH), insulin and IGF1, which is drastically altered under extreme metabolic conditions such as obesity, also plays relevant roles in the development, modulation and homeostasis of the PG. However, its implication in the pathophysiological interplay between obesity and prostate function is still to be elucidated. To explore this association, we used a high fat–diet obese mouse model, as well as in vitro primary cultures of normal‐mouse PG cells and human prostate cancer cell lines. This approach revealed that most of the components of the GH/insulin/IGF1 regulatory axis are present in PGs, where their expression pattern is altered under obesity conditions and after an acute insulin treatment (e.g. Igfbp3), which might have some pathophysiological implications. Moreover, our results demonstrate, for the first time, that the PG becomes severely insulin resistant under diet‐induced obesity in mice. Finally, use of in vitro approaches served to confirm and expand the conception that insulin and IGF1 play a direct, relevant role in the control of normal and pathological PG cell function. Altogether, these results uncover a fine, germane crosstalk between the endocrine–metabolic status and the development and homeostasis of the PG, wherein key components of the GH, insulin and IGF1 axes could play a relevant pathophysiological role.     

BiPPred: Combined sequence‐ and structure‐based prediction of peptide binding to the Hsp70 chaperone BiP

Substrate binding to Hsp70 chaperones is involved in many biological processes, and the identification of potential substrates is important for a comprehensive understanding of these events. We present a multi‐scale pipeline for an accurate, yet efficient prediction of peptides binding to the Hsp70 chaperone BiP by combining sequence‐based prediction with molecular docking and MMPBSA calculations. First, we measured the binding of 15mer peptides from known substrate proteins of BiP by peptide array (PA) experiments and performed an accuracy assessment of the PA data by fluorescence anisotropy studies. Several sequence‐based prediction models were fitted using this and other peptide binding data. A structure‐based position‐specific scoring matrix (SB‐PSSM) derived solely from structural modeling data forms the core of all models. The matrix elements are based on a combination of binding energy estimations, molecular dynamics simulations, and analysis of the BiP binding site, which led to new insights into the peptide binding specificities of the chaperone. Using this SB‐PSSM, peptide binders could be predicted with high selectivity even without training of the model on experimental data. Additional training further increased the prediction accuracies. Subsequent molecular docking (DynaDock) and MMGBSA/MMPBSA‐based binding affinity estimations for predicted binders allowed the identification of the correct binding mode of the peptides as well as the calculation of nearly quantitative binding affinities. The general concept behind the developed multi‐scale pipeline can readily be applied to other protein‐peptide complexes with linearly bound peptides, for which sufficient experimental binding data for the training of classical sequence‐based prediction models is not available. Proteins 2016; 84:1390–1407. © 2016 Wiley Periodicals, Inc.     

Blood sampling by puncture in the cavernous sinus from hunted wild boar

A new method of sampling based on the extraction of blood from the cavernous sinus of the dura mater has been assessed in hunted wild boar. Blood from 139 animals was obtained by two different extraction methods: the harvesting from thoracic cavity (TC) and intracavernous venipuncture (IV). Sera obtained by the IV method had higher volume (mean 2.85 vs 1.85 ml), were less hemolytic (mean absorbance at 450 nm: 1.01 vs 2.41 nm). A higher number of samples and a higher proportion of sera collected by IV (90.6 %) compared to those obtained using the TC method (78.4 %), could be analyzed against Aujeszky’s disease using blocking ELISA. No statistically significant differences in seroprevalences between samples obtained using both extraction methods were observed. The results obtained indicate that the IV is an easy, fast, reliable, clean, and safe method to collect blood samples from hunted wild boar, proving a real alternative to the traditional collection method.     

Microbiome structure of the fungid coral Ctenactis echinata aligns with environmental differences

The significance of bacteria for eukaryotic functioning is increasingly recognized. Coral reef ecosystems critically rely on the relationship between coral hosts and their intracellular photosynthetic dinoflagellates, but the role of the associated bacteria remains largely theoretical. Here, we set out to relate coral‐associated bacterial communities of the fungid host species Ctenactis echinata to environmental settings (geographic location, substrate cover, summer/winter, nutrient and suspended matter concentrations) and coral host abundance. We show that bacterial diversity of C. echinata aligns with ecological differences between sites and that coral colonies sampled at the species’ preferred habitats are primarily structured by one bacterial taxon (genus Endozoicomonas) representing more than 60% of all bacteria. In contrast, host microbiomes from lower populated coral habitats are less structured and more diverse. Our study demonstrates that the content and structure of the coral microbiome aligns with environmental differences and denotes habitat adequacy. Availability of a range of coral host habitats might be important for the conservation of distinct microbiome structures and diversity.     

New cationic exchanger support for reversible immobilization of proteins

New tailor-made cationic exchange resins have been prepared by covalently binding aspartic-dextran polymers (e.g. MW 15 000-20 000) to porous supports (aminated agarose and Sepabeads). More than 80% of the proteins contained in crude extracts from Escherichia coli and Acetobacter turbidans have been strongly adsorbed on these porous materials at pH 5. This interaction was stronger than in conventional carboxymethyl cellulose (e.g., at pH 7 and 25 degrees C, all proteins previously adsorbed at pH 5 were released from carboxymethyl cellulose, whereas no protein was released from the new supports under similar conditions). Ionic exchange properties of such composites were strongly dependent on the size of the aspartic-dextran polymers as well as on the exact conditions of the covalent coating of the solids with the polymer (optimal conditions: 100 mg aspartic-dextran 20 000/(mL of support); room temperature). Finally, some industrially relevant enzymes (Kluyveromices lactis, Aspergillus oryzae, and Thermus sp. beta-galactosidases, Candida antarctica B lipase, and bovine pancreas trypsin and chymotrypsin) have been immobilized on these supports with very high activity recovery and immobilization rates. After enzyme inactivation, the enzyme can be fully desorbed from the support and the support could be reused for several cycles.     

Beyond directed evolution: Darwinian selection as a tool for synthetic biology

Synthetic biology is an engineering approach that seeks to design and construct new biological parts, devices and systems, as well as to re-design existing components. However, rationally designed synthetic circuits may not work as expected due to the context-dependence of biological parts. Darwinian selection, the main mechanism through which evolution works, is a major force in creating biodiversity and may be a powerful tool for synthetic biology. This article reviews selection-based techniques and proposes strict Darwinian selection as an alternative approach for the identification and characterization of parts. Additionally, a strategy for fine-tuning of relatively complex circuits by coupling them to a master standard circuit is discussed.     

Metabolic engineering of isoprenoid biosynthesis in Arabidopsis for the production of taxadiene, the first committed precursor of Taxol

Paclitaxel (Taxol) is a widely used anticancer isoprenoid produced by the secondary metabolism of yew (Taxus sp.) trees. However, only limited amounts of Taxol or related metabolites (taxoids) can be obtained from the currently available sources. In this work we have taken the first step toward genetically engineering the biosynthesis of taxoids in angiosperms. The first committed step in Taxol biosynthesis is the production of taxadiene from geranylgeranyl diphosphate (GGPP), catalyzed by the plastid-localized enzyme taxadiene synthase (TXS). A recombinant T. baccata TXS lacking the putative plastid targeting peptide and fused to a C-terminal histidine (His) tag was shown to be enzymatically active in Escherichia coli. Constitutive production of the full-length His-tagged enzyme in Arabidopsis thaliana plants led to the accumulation of taxadiene and concomitant growth retardation and decreased levels of photosynthetic pigment in transgenic plants. Although these phenotypes may derive from a toxic effect of taxadiene, the lower accumulation of endogenous plastid isoprenoid products such as carotenoids and chlorophylls in transgenic plants also suggests that the constitutive production of an active TXS enzyme might alter the balance of the GGPP pool. Induction of transgene expression using a glucocorticoid-mediated system consistently resulted in a more efficient recruitment of GGPP for the production of taxadiene, which reached levels 30-fold higher than those in plants constitutively expressing the transgene. This accomplishment illustrates the possibility of engineering the production of taxoids and other GGPP-derived isoprenoids in crop plants despite the constraints associated with limited knowledge with regard to regulation of GGPP availability.