Effects of larval diet on development rates and reproductive maturation of male and female Mediterranean fruit flies

Abstract Mediterranean fruit fly Ceratitis capitata (Diptera: Tephritidae) larvae are capable of developing in one of many hosts that may vary greatly in quality. We hypothesized that they will respond to the larval environment in a manner beneficial to their subsequent reproductive performance. Accordingly, we investigated the effects of various larval diets (varying in the amount of protein and sugar they contain) on the size, development time, nutritional status and reproductive maturation (ovarian development and onset of sexual behaviour) of females and males. We found that flies which undergo larval development in artificial host fruit that contain sugar and protein ('protein-fed') were larger, developed faster and emerged with more nutritional reserves than flies that were protein-deprived as larvae. Protein-fed males, regardless of their size, became sexually active before males that developed in hosts with no protein. Protein-fed females produced more mature eggs than protein-deprived ones. Moreover, protein-fed females tended to copulate sooner than females that developed in hosts with no protein. In addition, regardless of female larval diet, females with more mature eggs tended to copulate sooner than females with less mature eggs. In light of these results, the importance of the larval environment for adult reproductive success is discussed.     

In vivo visualization of<Emphasis Type="Italic"> Tradescantia</Emphasis> leaf tissue and monitoring the physiological and morphological states under different water supply conditions using optical coherence tomography

The optical coherence tomography (OCT) capabilities of plants were evaluated using leaves of Tradescantia pallida (Rose) D. Hunt. The internal structure of the leaf tissues was visualized in vivo and the physiological and morphological states of the tissues under different water supply conditions were monitored using OCT. The OCT technique provides non-invasive two-dimensional images directly on intact plants. The acquisition time of a two-dimensional image with a size of 200×200 pixels and a spatial resolution of 15 m is 1–3 s. It was shown that OCT is a useful tool for monitoring the physiological and morphological states of plant tissues supplied with varying amounts of water and under the influence of different chemical factors.Abbreviation OCT Optical coherence tomography     

Effects of neonatal fluvoxamine administration to white rats and their correction by semax treatment

The aim of this work was to study the delayed effects of chronic neonatal administration of the selective serotonin reuptake inhibitor fluvoxamine (FA) to white rat pups and to estimate the possibility to correct these effects by treatment with semax. Fluvoxamine was injected intraperitoneally at a dose of 10 mg/kg from postnatal days 1 to 14, and semax was injected intranasally at a dose of 0.05 mg/kg from postnatal days 15 to 28. It was shown that neonatal FA administration produced a significant delay in animal somatic growth. A loss in body weight was detected both during FA administration and 4–6 weeks after the last injection. Furthermore, FA administration increased the anxiety level and disturbed the learning ability of animals. The negative consequences of neonatal FA administration were largely compensated by Semax.     

Noninvasive estimation of the oxygen status of experimental tumors by diffuse optical spectroscopy

The potentialities of diffuse optical spectroscopy for noninvasive estimation of the oxygen status of experimental tumors have been demonstrated. The distribution of total, oxygenated, and deoxygenated hemoglobin, as well as the level of oxygen saturation of blood have been assessed using two tumor models differing in the histological structure and functional characteristics. The results obtained by the optical method have been verified by immunohistochemical examination of tissue specimens with an exogenous hypoxia marker pimonidazole.     

Influence of original structural analogue of arginine-vasopressin(6–9), Ac-D-SPRG,on exploratory activity and level of anxiety of white rats

Influence of synthetic analogue of arginine-vasopressin (AVP), Ac-D-SPRG, on exploratory behavior and level of anxiety of white rats was investigated. Ac-D-SPRG was injected nasally in doses of 0.01, 0.1, 1.0, and 10.0 μg/kg in the volume of 1 μl per 10 g of body weight 5 min before the testing. The analogue caused depression of orientation and exploratory activity (OEA) and increase of anxiety level in animals. The contradictory literature data provide no opportunity to conclude unambiguously on mechanisms underlying bases of regulation of anxiety level and OEA from AVP but nevertheless confirm the participation of this hormone in a given process.     

Semax prevents learning and memory inhibition by heavy metals

Separate and joint effect of Semax, ascorbic acid, lead diacetate, and ammonium molybdate on avoidance conditioning in rats was studied. It was established that the heavy metal salts inhibited the avoidance response, and the peptide counteracted this inhibition as strongly as ascorbic acid or to a comparable degree. These findings confirm the antioxidant properties of Semax.     

Individual optimization: Mechanisms shaping the optimal reaction norm

In general, optimal reaction norms in heterogeneous populations can be obtained only by iterative numerical procedures (McNamara, 1991; Kawecki and Stearns, 1993). We consider two particular, but biologically plausible and analytically tractable cases of individual optimization to gain insight into the mechanisms which shape the optimal reaction norm of fecundity in relation to an environmental variable or an individual trait. In the first case, we assume that the quality of the environment (e.g. food abundance) or the quality of the individual (e.g. body size) is fixed during its entire life; it may also be a heritable individual trait. In the second case, individual quality is assumed to change randomly such that the probability distribution of quality in the next year is the same for the parent and for her offspring. For these two cases, we obtain analytical expressions for the shape of the optimal reaction norm, which are heuristically interpretable in terms of underlying selective mechanisms. It is shown that better quality may reduce the optimal fecundity. This outcome is particularly likely if better quality increases a fecundity-independent factor of parental survival in a long-lived species with fixed quality. This revised version was published online in July 2006 with corrections to the Cover Date.     

Effect of the peptide Semaks on UV-induced damaging of the plasma membranes of peritoneal macrophages in mice

We studied the effect of nootropic peptide Semaks and its inactive analog on the efficiency of UV-induced damaging of the peritoneal macrophage plasma membrane. The increase of the time after the UV-irradiation (with doses 5 and 6 J/cm²) from 15 to 60 min led to a substantial increase in the number of damaged cells. The UV-irradiation effect has been subjected to a substantial decrease with the adding of Semaks to the incubation medium immediately after irradiation.     

Damage to plasmatic membranes of mice peritoneal macrophages under the influence of H<Subscript>2</Subscript>O<Subscript>2</Subscript>

Using the microfluorescent method of identification of damaged plasmatic membranes, the influence of hydrogen peroxide on mice peritoneal macrophages was determined. H₂O₂ in vitro produced a destructive effect on the cells depending on the temperature, time of incubation, and concentration of the agent. The damage increases after the incubation medium is replaced with Hanks solution containing no H₂O₂.     

Method for Primary Screening of Pharmaceuticals on the Paramecium caudatum Eukaryotic Cell Model

Doklady Biochemistry and Biophysics - The&nbsp; effect&nbsp; of &nbsp;adrenaline&nbsp; in &nbsp;various &nbsp;concentrations &nbsp;and&nbsp; dopamine &nbsp;at...