Male moth songs tempt females to accept mating: the role of acoustic and pheromonal communication in the reproductive behaviour of Aphomia sociella

Background

Members of the subfamily Galleriinae have adapted to different selective environmental pressures by devising a unique mating process. Galleriinae males initiate mating by attracting females with either chemical or acoustic signals (or a combination of both modalities). Six compounds considered candidates for the sex pheromone have recently been identified in the wing gland extracts of Aphomia sociella males. Prior to the present study, acoustic communication had not been investigated. Signals mediating female attraction were likewise unknown.

Methodology/Principal Findings

Observations of A. sociella mating behaviour and recordings of male acoustic signals confirmed that males initiate the mating process. During calling behaviour (stationary wing fanning and pheromone release), males disperse pheromone from their wing glands. When a female approaches, males cease calling and begin to produce ultrasonic songs as part of the courtship behaviour. Replaying of recorded courting songs to virgin females and a comparison of the mating efficiency of intact males with males lacking tegullae proved that male ultrasonic signals stimulate females to accept mating. Greenhouse experiments with isolated pheromone glands confirmed that the male sex pheromone mediates long-range female attraction.

Conclusion/Significance

Female attraction in A. sociella is chemically mediated, but ultrasonic communication is also employed during courtship. Male ultrasonic songs stimulate female sexual display and significantly affect mating efficiency. Considerable inter-individual differences in song structure exist. These could play a role in female mate selection provided that the female''s ear is able to discern them. The A. sociella mating strategy described above is unique within the subfamily Galleriinae.     

Biological effects of a de novo designed myxoma virus peptide analogue: evaluation of cytotoxicity on tumor cells

Background

The Resonant Recognition Model (RRM) is a physico-mathematical model that interprets protein sequence linear information using digital signal processing methods. In this study the RRM concept was employed for structure-function analysis of myxoma virus (MV) proteins and the design of a short bioactive therapeutic peptide with MV-like antitumor/cytotoxic activity.

Methodology/Principal Findings

The analogue RRM-MV was designed by RRM as a linear 18 aa 2.3 kDa peptide. The biological activity of this computationally designed peptide analogue against cancer and normal cell lines was investigated. The cellular cytotoxicity effects were confirmed by confocal immunofluorescence microscopy, by measuring the levels of cytoplasmic lactate dehydrogenase (LDH) and by Prestoblue cell viability assay for up to 72 hours in peptide treated and non-treated cell cultures. Our results revealed that RRM-MV induced a significant dose and time-dependent cytotoxic effect on murine and human cancer cell lines. Yet, when normal murine cell lines were similarly treated with RRM-MV, no cytotoxic effects were observed. Furthermore, the non-bioactive RRM designed peptide RRM-C produced negligible cytotoxic effects on these cancer and normal cell lines when used at similar concentrations. The presence/absence of phosphorylated Akt activity in B16F0 mouse melanoma cells was assessed to indicate the possible apoptosis signalling pathway that could be affected by the peptide treatment. So far, Akt activity did not seem to be significantly affected by RRM-MV as is the case for the original viral protein.

Conclusions/Significance

Our findings indicate the successful application of the RRM concept to design a bioactive peptide analogue (RRM-MV) with cytotoxic effects on tumor cells only. This 2.345 kDa peptide analogue to a 49 kDa viral protein may be suitable to be developed as a potential cancer therapeutic. These results also open a new direction to the rational design of therapeutic agents for future cancer treatment.     

Increased expression and altered subcellular distribution of PKC-delta in chronically hypoxic rat myocardium: involvement in cardioprotection

We examined the role of protein kinase C (PKC) in the cardioprotective mechanism induced by long-term adaptation to chronic intermittent hypoxia. Adult male Wistar rats were exposed to hypobaric hypoxia of 7,000 m for 8 h/day, 5 days/wk; the total number of exposures was 24-32. A control group was kept under normoxic conditions. Western blot analysis of PKC isoforms-delta and -epsilon was performed in the cytosol and three particulate fractions of left ventricular myocardium. Infarct size was determined in open-chest animals subjected to 20-min coronary artery occlusion and 3-h reperfusion. The PKC inhibitors chelerythrine (1 or 5 mg/kg) or rottlerin (selective for PKC-delta isoform; 0.3 mg/kg) were administered intravenously as a single bolus 15 min before ischemia. Chronic hypoxia had no effect on the expression and distribution of PKC-epsilon. The relative amount of PKC-delta increased in the cytosol and nuclear-cytoskeletal, mitochondrial, and microsomal fractions of chronically hypoxic myocardium by 100%, 212%, 237%, and 146%, respectively, compared with corresponding normoxic values. Chronic hypoxia decreased the size of myocardial infarction (normalized to the area at risk) by about one-third on the average (P < 0.05). Both doses of chelerythrine tended to reduce infarction in controls, and only the high dose completely abolished the improvement of ischemic tolerance in hypoxic hearts (P < 0.05). Rottlerin attenuated the infarct size-limiting effect of chronic hypoxia (P < 0.05), and it had no effect in controls. These results suggest that chronic intermittent hypoxia-induced cardioprotection in rats is partially mediated by PKC-delta; the contribution of other isoforms remains to be determined.     

Theoretical and spectroscopic evidence for coordination ability of 3,3'-benzylidenedi-4-hydroxycoumarin. New neodymium (III) complex and its cytotoxic effect

Theoretical and spectroscopic studies of 3,3'-benzylidenedi-4-hydroxycoumarin (bhc) have been performed. B3LYP/6-31G* calculations reproduced the experimental molecular structure of bhc and showed two O-H...O asymmetrical intramolecular hydrogen bonds with O...O distances 2.638 and 2.696 A. The calculated Fukui functions and Molecular Electrostatic Potential for bhc and its deprotonated form, bhc(2-), predicted that the most probable reactive sites for electrophilic attack and hydrogen bonds are the carbonyl oxygens, followed by the hydroxyl oxygens. The coordination ability of 3,3'-benzylidenedi-4-hydroxycoumarin has been proved in a complexation reaction with neodymium (III) ion. The new neodymium (III) complex of bhc was studied by elemental analyses, conductivity and other physical properties, mass spectra, (1)H, (13)C NMR, UV-Vis and IR spectroscopy. The data obtained are in agreement with the metal:ligand ratio of 1:1, and the formula Nd(bhc(2-))(OH)(H(2)O), where bhc(2-)=C(25)H(14)O(6)(2-). The vibrational analysis of the neodymium (III) complex, free bhc, and its monomeric building block, 4-hydroxycoumarin, showed that in the Nd(III) complex the ligand coordinates to the metal ion through both deprotonated hydroxyl groups. The participation of both carbonyl groups in coordination to the metal ion was confirmed by the significant shift of nu(C=O) to lower wavenumber. The evaluation of the cytotoxic activity of the new Nd(III) complex on SKW-3 and HL-60/Dox cells revealed, that it is a potent cytotoxic agent and should be subset further to more detailed pharmacological and toxicological study.     

Morpho-functional features in adolescent males under iodine deficiency of the Saratov region

An auxological study of 538 adolescent males (from 12 to 17) from different settlements of the Saratov region with various degrees of industrialization and iodine deficiency was carried out. All subjects have undergone an ultra-sound screening of thyroid volume to reveal the frequency of endemic goiter in each group. The results obtained during investigation showed the existence of deviations in the physical development of boys with goiter in skinfold thickness, body circumferences (chest, shoulder, and forearm), biacromial and biiliocristal diameters, transversal and sagittal chest diameters, body height and weight, BMI, leg length, and corpus length, all of which are greater in healthy adolescents (SD = 1.0, p = 0.000). In 46 subjects with endemic goiter, characteristics of metabolic status were investigated by the method of registration of endogenous intoxication (Malakhova, 1995). In comparison to the control group, a 1.2 times lower LAMM level in erythrocytes (p < 0.05) and 1.1 in urine (p < 0.05), and an increase by 2.3 in the LAMM level in blood plasma (p < 0.01) were detected. The relative percentage of catabolic substances exceeded the control values by 3.2 (p < 0.001). The OP level in erythrocytes is reduced by 2.2 (p < 0.01), in urine (p < 0.01) by 8.4. The OP level is higher in plasma by 3.0 (p < 0.01). The adolescents with endemic goiter have a reallocation of protein matter between erythrocytes, plasma and urine. The spectrogram of erythrocytes shows lowering metabolites on membrane frames, which testifies to the destruction of the structurally functional properties of erythrocytes, and a lowering of absorption properties in glycocalix erythrocytes.     

Formation of trans-verbenol and verbenone from alpha-pinene catalysed by immobilised Picea abies cells

Both enantiomers and the racemate of alpha-pinene were transformed by Picea abies cells immobilised on alginate. The main products were cis- and trans-verbenol, the later being further transformed to verbenone. The enantiomeric purity of each product more or less corresponded to that of the substrate. Transformation by free cells was faster than that by the immobilised cells. The ratio of products differed to some extent between the transformation by free and immobilised cells.