Developmental effects of modifiers of the vg mutant in Drosophila melanogaster

An analysis of the modifiers affecting the expression of the vg gene was performed. We selected for weak and strong expression of the vg mutant in F2 segregating populations obtained by crossing a vestigial stock with an Oregon laboratory stock (O) and with a wild strain (B) captured near Bologna, Italy. The selection for enlarged wings was more effective in the vg B population where wild wings appeared from the 10th generation. The assay of the three major chromosomes showed that the modifiers are located on chromosomes 2 and 3. The mutant imaginal disc cell death phenotype is evident in vg/vg strains that have a wild-type wing phenotype. It is suggested that the selected modifiers do not prevent cell death but induce regenerative growth.     

High Intensity Interval Training (HIIT) Induces Specific Changes in Respiration and Electron Leakage in the Mitochondria of Different Rat Skeletal Muscles

High intensity interval training (HIIT) is characterized by vigorous exercise with short rest intervals. Hydrogen peroxide (H₂O₂) plays a key role in muscle adaptation. This study aimed to evaluate whether HIIT promotes similar H₂O₂ formation via O₂ consumption (electron leakage) in three skeletal muscles with different twitch characteristics. Rats were assigned to two groups: sedentary (n=10) and HIIT (n=10, swimming training). We collected the tibialis anterior (TA-fast), gastrocnemius (GAST-fast/slow) and soleus (SOL-slow) muscles. The fibers were analyzed for mitochondrial respiration, H₂O₂ production and citrate synthase (CS) activity. A multi-substrate (glycerol phosphate (G3P), pyruvate, malate, glutamate and succinate) approach was used to analyze the mitochondria in permeabilized fibers. Compared to the control group, oxygen flow coupled to ATP synthesis, complex I and complex II was higher in the TA of the HIIT group by 1.5-, 3.0- and 2.7-fold, respectively. In contrast, oxygen consumed by mitochondrial glycerol phosphate dehydrogenase (mGPdH) was 30% lower. Surprisingly, the oxygen flow coupled to ATP synthesis was 42% lower after HIIT in the SOL. Moreover, oxygen flow coupled to ATP synthesis and complex II was higher by 1.4- and 2.7-fold in the GAST of the HIIT group. After HIIT, CS activity increased 1.3-fold in the TA, and H₂O₂ production was 1.3-fold higher in the TA at sites containing mGPdH. No significant differences in H₂O₂ production were detected in the SOL. Surprisingly, HIIT increased H₂O₂ production in the GAST via complex II, phosphorylation, oligomycin and antimycin by 1.6-, 1.8-, 2.2-, and 2.2-fold, respectively. Electron leakage was 3.3-fold higher in the TA with G3P and 1.8-fold higher in the GAST with multiple substrates. Unexpectedly, the HIIT protocol induced different respiration and electron leakage responses in different types of muscle.     

Molecular taxonomic identification in the absence of a ‘barcoding gap’: a test with the endemic flora of the Canarian oceanic hotspot

We use a comprehensive subset of Canarian angiosperms corresponding to 23 families, 35 genera and 60 Canarian endemic taxa to test whether this flora is suitable to taxonomic identification with the two proposed plant DNA barcode sequences and whether these sequences may reveal the existence of cryptic species overlooked by morphology. The rate of discrimination success between the insular congeneric samples using the rbcL+matK combination and a ‘character‐based’ approach (where we use only the combination of nucleotide positions in an alignment that allows unambiguous species identification) is higher (82.29%) than that obtained with the ‘distance‐based’ approach (80.20%) used by the CBOL Plant Working Group in 2009 and also when compared with tests conducted in other floras. This suggests that the molecular identification of the Canarian endemic flora can be achieved as successfully as in other floras where the incidence of radiation is not as relevant. The facts that (i) a distance‐based criterion was unable to discriminate between congeneric and conspecific comparisons and (ii) only the character‐based discrimination criterion resolved cases that the distance‐based criterion did not, further support the use of a character discrimination approach for a more efficient DNA barcoding of floras from oceanic islands like the Canaries. Thus, a barcoding gap seems not to be necessary for the correct molecular characterization of the Canarian flora. DNA barcodes also suggest the possible existence of cryptic taxa to be further investigated by morphology and that the current taxonomic status of some of the taxa analysed may need revision.     

Sex-Specific Mediating Role of Insulin Resistance and Inflammation in the Effect of Adiposity on Blood Pressure of Prepubertal Children

Objective

To evaluate the association between obesity indices and blood pressure (BP) at 4 years of age, in each sex, and to quantify to which extent this association is mediated by inflammation and insulin resistance (IR).

Materials and Methods

We studied 1250 4-year-old children selected from the population-based birth cohort Generation XXI. Associations between body mass index (BMI) z-score and waist-to-height ratio (WHtR), office BP, inflammation (high sensitivity C-reactive protein) and IR (HOMA-IR index) were assessed. Path Analysis, a modified multivariate regression approach, was applied to test causal models and quantify direct and indirect effects of predictors of systolic (SBP) and diastolic BP (DBP).

Results

SBP and DBP increased significantly with BMI and WHtR in both sexes. There was a strong direct association (explaining 74.1-93.2% of the total association) of both measures of adiposity with SBP, in both sexes. This association was additionally indirectly mediated by IR, particularly regarding WHtR (20.5% in girls and 9.4% in boys). Mediation by inflammation did not reach statistical significance in either sex. Regarding DBP, the direct effect of adiposity was strong (>95% for BMI and WHtR in boys) and the mediation by IR was much smaller in boys than in girls.

Discussion

The direct association between adiposity and BP in healthy 4-year-old children is strong and IR plays an important mediating role. The strength of effects of IR and inflammation suggests sex differences in the complex interplay between BP, adiposity and inflammation.     

Asymmetrical Dependence Between a Neotropical Mistletoe and its Avian Seed Disperser

The degree of interdependence among interacting species has major implications for our understanding of the coevolutionary process and biodiversity maintenance. However, the mutualism strength among fruiting plants and their seed dispersers remains poorly understood in tropical ecosystems. We evaluated simultaneously the effectiveness of the avian seed dispersers of the mistletoe Struthanthus flexicaulis (Loranthaceae) and the contribution of its fruits to their diets in a highland rocky savanna in southeastern Brazil. The mistletoe fruits are small lipid‐rich pseudoberries available throughout the year. Four passerine birds fed on fruits, but Elaenia cristata (Tyrannidae) was the most effective disperser, responsible for more than 96 percent of the dispersed seeds. This bird swallowed fruits whole, expelling and depositing undamaged seeds by regurgitation and bill wiping on perches. From 646 dispersed seeds, 56 percent were deposited on safe sites, thin live twigs of 38 susceptible host species. Elaenia cristata were predominantly frugivorous, feeding on typically ornithocoric fruits of at least 12 species, but also on arthropods. Although fruits represented 75 percent of the feeding bouts along the year, S. flexicaulis fruits represented only 34 percent of the E. cristata diet. Our results highlight the asymmetrical nature of this mutualistic interaction, with the mistletoe life cycle locally linked to one highly effective seed disperser that is more weakly dependent on mistletoes fruits as a food source. We suggest that merging the seed dispersal effectiveness framework with diet assessment of seed dispersers is needed to clarify the asymmetries in mutualistic pairwise interactions involving plants and their animal partners.     

Letter to the Editor: Efficacy and safety of anti-Trop antibodies,R. Cubas,M. Li,C. Chen and Q. Yao,Biochim Biophys Acta 1796 (2009) 309–1

Still little information is available on the efficacy and toxicity of anti-Trop-2 antibodies in man. Findings on antibodies anti-Trop-1/Ep-CAM, a paralog molecule of Trop-2, may provide preliminary indications, and a low-affinity anti-Trop-1/Ep-CAM monoclonal antibody, failed to show any benefit in colon cancer patients. Other anti-Trop-1 antibodies, e.g. MT201, may bear more promise, as may more advanced molecular forms, e.g. a BiTE design (MT110) or trifunctional antibodies (catumaxomab). However, the efficacy of these reagents in cancer patients still needs to be proven in randomized clinical trials.     

Use of morphometric parameters for tracking ovule and microspore evolution in grapevine (<Emphasis Type="Italic">Vitis vinifera</Emphasis> L., cv. “Aragonez”) and evaluation of their potential to improve <Emphasis Type="Italic">in vitro</Emphasis> somatic embryogenesis efficiency from gametophyte tissues

Somatic embryogenesis induction from in vitro cultured stamens and carpels is highly dependent on explants’ inoculation at specific developmental stages. To establish good correlations between measurable morphometric parameters of flowers or flower buds and developmental stages of micro- and macrosporogenesis, this procedure is the easiest way to simplify the in vitro culture procedures. These correlations were established here for the most important Iberian grapevine cultivar, the “Aragonez”, named “Tempranillo” in Spain and “Tinta Roriz” in the north of Portugal, and were based in floral buds and anther measurements. The anther length, with a correlation coefficient of 0.90, proved to be the best morphometric parameter to follow microsporogenesis evolution. A correlation between micro- and macrosporogenesis evolutionary stages was also positively established, allowing the use of morphometric parameters for tracking ovule evolution as well. Carpels in several evolutionary stages were in vitro cultured to evaluate the aging effect on the capacity for somatic embryogenesis induction. Explants inoculated in the earliest stages of macrosporogenesis presented the best results. Media culture formulations were also tested for ovary culture, with the best results being achieved with a 5:1 auxin/cytokinin ratio.     

Immunoproteomics of the active degradome to identify biomarkers for Trichomonas vaginalis

Trichomonas vaginalis, a sexually transmitted parasite, has many cysteine proteinases (CPs); some are involved in trichomonal pathogenesis, express during infection, and antibodies against CPs have been detected in patient sera. The goal of this study was to identify the antigenic proteinases of T. vaginalis as potential biomarkers for trichomonosis. The proteases detected when T. vaginalis protein extracts are incubated without protease inhibitors, the trichomonad‐active degradome, and the immunoproteome were obtained by using 2‐DE, 2‐D‐zymograms, 2‐D‐Western blot (WB) assays with trichomonosis patient sera, and MS analysis. Forty‐nine silver‐stained spots were detected in the region of 200–21 kDa of parasite protease‐resistant extracts. A similar proteolytic pattern was observed in the 2‐D zymograms. Nine CPs were identified in the 30 kDa region (TvCP1, TvCP2, TvCP3, TvCP4, TvCP4‐like, TvCP12, TvCPT, TvLEGU‐1, and another legumain‐like CP). The major reactive spots to T. vaginalis‐positive patient sera by 2‐D‐WB corresponded to four papain‐like (TvCP2, TvCP4, TvCP4‐like, TvCPT), and one legumain‐like (TvLEGU‐1) CPs. The genes of TvCP4, TvCPT, and TvLEGU‐1 were cloned, sequenced, and expressed in Escherichia coli. Purified recombinant CPs were recognized by culture‐positive patient sera in 1‐D‐WB assays. These data show that some CPs could be potential biomarkers for serodiagnosis of trichomonosis.