Photo-thermal regulation of diapause in Trichogramma piceum Djur. (Hymenoptera, Trichogrammatidae)

Interaction of the photoperiodic conditions of development of maternal females (day lengths of 2 to 22 h at 20°C) with the thermal regime of development of their progeny (temperature of 12 to 15°C at day length of 12 h) in determination of prepupal diapause in Trichogramma piceum was studied under laboratory conditions. At 15°C the diapause was practically absent. At lower temperatures, the proportion of diapausing prepupae was maximal (25% of larvae at 14°C, 70% of larvae at 13°, and 80% of larvae at 12°C) if the maternal females developed under short day conditions (10–12 h). When maternal females developed at day lengths of 18–20 h, diapause was rarely recorded at all temperatures, while ultra-short (less than 8–10 h) days also caused a decrease in the proportion of diapausing progeny. The right (ecologically important) threshold of this maternal long-day photoperiodic response was about 14–15 h independently of the temperature during the progeny development. These results make it possible to clarify the mechanism of the “maternal photoperiodic correction of the progeny thermal response.” Although the impact of the maternal photoperiodic response can be revealed only within a very narrow thermal range, the relative strength of the diapause-inducing effect of different day lengths is independent of the temperature regimen of the progeny development.     

Photoperiodic responses of pupa and adult determining maternal influence on progeny diapause in two species of the genus Trichogramma (Hymenoptera, Trichogrammatidae)

The adult photoperiodic responses of two Trichogramma species were investigated by exposing adults during 3 days to one of the seven light: dark regimes: L: D = 4: 20, 8: 16, 12: 12, 14: 10, 16: 8, 18: 6, and 20: 4. The preimaginal stages of these individuals developed under short (L: D = 12: 12), long (L: D = 20: 4) or intermediate photoperiods (L: D = 14: 10 and L: D = 16: 8 for Trichogramma principium and T. embryophagum, respectively). The progeny of these females developed under short day L: D = 12: 12 and at two moderately diapause-inducing temperatures (13 and 14°C for T. principium, 14 and 15°C for T. embryophagum). In both Trichogramma species which developed at both temperatures, the percentage of diapausing prepupae was significantly dependent both on the photoperiodic conditions of the preimaginal development of the maternal generation and on the photoperiod which influenced the adult females. The adults showed a typical long-day photoperiodic response with a threshold day length of ca 13 h in T. principium and ca 16 h in T. embryophagum, which practically coincided with the thresholds of the pupal photoperiodic responses of these species revealed in our previous studies. However, the ultra-short photoperiods (L: D = 4: 20 and 8:16) caused a relatively stronger diapause-inducing effect on the progeny when applied to the adult females than when it was applied to the pupae. Thus, in both the Trichogramma species studied, the patterns of photoperiodic responses of pupa and adult were somewhat different although they almost coincided in the “ecologically significant” part of the photoperiodic scale.     

Effects of cold shock on host egg parasitization by females of Trichogramma buesi Voegele (Hymenoptera, Trichogrammatidae)

The effects of cold shock (4°C for 18–24 h) on survival of Trichogramma buesi females, their fecundity, and the inclination to parasitize grain moth eggs were studied under laboratory conditions. Cold shock did not result in any significant change in the survival rate, whereas the fraction of females that parasitized grain moth eggs and the fecundity of these females slightly decreased. However, females which had already started oviposition before cold shock infested grain moth eggs much more frequently. In most insect species studied, cold shock results in a sharp decrease or even disruption of the effect of experience on the subsequent behavior. Thus, the results of this study suggest that “the effect of acquired experience” (a tendency to continue infestation of the particular host species) in Trichogramma females is based not on learning or not only on learning but on some other, possibly hormonal mechanisms.     

Surface functionalization of carbon nanomaterials by self‐assembling hydrophobin proteins

Class I fungal hydrophobins are small surface‐active proteins that self‐assemble to form amphipathic monolayers composed of amyloid‐like rodlets. The monolayers are extremely robust and can adsorb onto both hydrophobic and hydrophilic surfaces to reverse their wettability. This adherence is particularly strong for hydrophobic materials. In this report, we show that the class I hydrophobins EAS and HYD3 can self‐assemble to form a single‐molecule thick coating on a range of nanomaterials, including single‐walled carbon nanotubes (SWCNTs), graphene sheets, highly oriented pyrolytic graphite, and mica. Moreover, coating by class I hydrophobin results in a stable, dispersed preparation of SWCNTs in aqueous solutions. No cytotoxicity is detected when hydrophobin or hydrophobin‐coated SWCNTs are incubated with Caco‐2 cells in vitro. In addition, we are able to specifically introduce covalently linked chemical moieties to the hydrophilic side of the rodlet monolayer. Hence, class I hydrophobins provide a simple and effective strategy for controlling the surfaces of a range of materials at a molecular level and exhibit strong potential for biomedical applications. © 2012 Wiley Periodicals, Inc.     

The rate of preimaginal development of the blowfly, Calliphora vicina R.-D. (Diptera, Calliphoridae) under field and laboratory conditions

Open field experiments with the blowfly, Calliphora vicina originating from the environs of St. Petersburg showed that the correlation between the rate of its preimaginal development under the natural conditions and the mean daily temperature could be very closely approximated by linear regression. The sum of effective temperatures required for development from the egg to the puparium constituted ca 140 degree-days and from the egg to the adult, ca 320 degree-days with the lower thresholds of 5.8 and 4.8°C, respectively. The minimum duration of development (6–8 days from the egg to the puparium and 16–20 days from the egg to the adult) was recorded during the period of the highest mean temperatures (22–23°C) from July 8 to August 15 of 2010 and 2011. The rate of development under natural thermorhythms was not siggnificantly different from that under the laboratory conditions at constant temperatures from 12 to 23°C.     

Biodiesel fuel production from lipids of filamentous fungi

The main stages in the production of biodiesel fuel from lipids of filamentous fungi belonging to the order Mucorales are described. Fungi of the family Cunninghamellaceae have been screened; the lipogenic activity of the examined strains has been assessed; and a producer generating up to 50% of lipids, represented by triacylglycerols, has been found. The substitution effect of a source of carbon and nitrogen with less expensive components (in particular, various industrial wastes) has been studied, as well as their influence on the quantity and major characteristics of the final product. An ecologically friendly method for extracting lipids from fungal mycelia, utilizing supercritical technologies, has been used. A correlation between the lipid content in the spore inoculum and the maximal lipid content in biomass has been discovered; this correlation is proposed for optimizing the biotechnology and increasing the yield of final products.     

Seed hairs of poplar trees as natural airborne pollen trap for allergenic pollen grains

The present article deals with the efficacy of seed hairs of poplar trees (Populus spp.) as a potent natural airborne pollen trap. Different species of Populus are commonly found planted along the streets in the cities of North China. The seed hairs and pericarp of poplar trees were collected from the trees and on the ground in Beijing Botanical Garden of Chinese Academy of Sciences and around Miyun Reservoir during May 2005 for pollen analysis. Different pollen spectra are recorded from different samples and are characterised by dominant occurrence of pollen grains of arboreal and anemophilous plants. In addition, pollen grains of non‐arboreal plants including grasses are also found trapped. Among the 46 trapped pollen grains, 26 are known to be allergenic. This study suggests that poplar seed hairs possibly make people feel uncomfortable due to the presence of allergenic pollen trapped in the hairs.     

TOPS-MODE model of multiplexing neuroprotective effects of drugs and experimental-theoretic study of new 1,3-rasagiline derivatives potentially useful in neurodegenerative diseases

The interest on computational techniques for the discovery of neuroprotective drugs has increased due to recent fail of important clinical trials. In fact, there is a huge amount of data accumulated in public databases like CHEMBL with respect to structurally heterogeneous series of drugs, multiple assays, drug targets, and model organisms. However, there are no reports of multi-target or multiplexing Quantitative Structure–Property Relationships (mt-QSAR/mx-QSAR) models of these multiplexing assay outcomes reported in CHEMBL for neurotoxicity/neuroprotective effects of drugs. Accordingly, in this paper we develop the first mx-QSAR model for multiplexing assays of neurotoxicity/neuroprotective effects of drugs. We used the method TOPS-MODE to calculate the structural parameters of drugs. The best model found correctly classified 4393 out of 4915 total cases in both training and validation. This is representative of overall train and validation Accuracy, Sensitivity, and Specificity values near to 90%, 98%, and 80%, respectively. This dataset includes multiplexing assay endpoints of 2217 compounds. Every one compound was assayed in at least one out of 338 assays, which involved 148 molecular or cellular targets and 35 standard type measures in 11 model organisms (including human). The second aim of this work is the exemplification of the use of the new mx-QSAR model with a practical case of study. To this end, we obtained again by organic synthesis and reported, by the first time, experimental assays of the new 1,3-rasagiline derivatives 3 different tests: assay (1) in absence of neurotoxic agents, (2) in the presence of glutamate, and (3) in the presence of H₂O₂. The higher neuroprotective effects found for each one of these assays were for the stereoisomers of compound 7: compound 7b with protection = 23.4% in assay (1) and protection = 15.2% in assay (2); and for compound 7a with protection = 46.2% in assay (3). Interestingly, almost all compounds show protection values >10% in assay (3) but not in the other 2 assays. After that, we used the mx-QSAR model to predict the more probable response of the new compounds in 559 unique pharmacological tests not carried out experimentally. The results obtained are very significant because they complement the pharmacological studies of these promising rasagiline derivatives. This work paves the way for further developments in the multi-target/multiplexing screening of large libraries of compounds potentially useful in the treatment of neurodegenerative diseases.     

Peculiarities of chromosome organization in meiosis

Meiotic and mitotic chromosomes have a complex of differences. (1) At the early prophase I of meiosis, chromosomes acquire protein axial elements (AEs) that were absent in mitosis; in addition to somatic cohesins, AEs contain the meiosis-specific cohesins REC8, SMC1β, and STAG3. (2) At the middle prophase I, protein lateral elements (LEs) of synaptonemal complexes (SCs) are formed on the basis of AEs. The LE proteins are not conserved, but in Saccharomyces cerevisiae and Arabidopsis thaliana they contain functional domains with conserved secondary structures. Among the almost 679 thousand proteins of primitive eukaryotes that we studied by bioinformatics methods, in green and brown algae, some lower fungi, and Coelenterata, we revealed proteins or functional domains similar to SC proteins. (3) During the pachytene and diplotene stages of meiosis, chromosomes of spermatocytes and mother pollen cells acquire a general structure resembling the structure of amphibian and avian lampbrush chromosomes in miniature. Lateral chromatin loops with sizes of 90, 160, and even over 480 Kb were observed in human spermatocytes during the diplotene stage. In combination, all these observations confirm the considerable conservation of the scheme of molecular and ultrastructural organization of meiotic chromosomes in a large variety of eukaryotic organisms.