Structural Basis for Allosteric Coupling at the Membrane-Protein Interface in Gloeobacter violaceus Ligand-gated Ion Channel (GLIC)

Ligand binding at the extracellular domain of pentameric ligand-gated ion channels initiates a relay of conformational changes that culminates at the gate within the transmembrane domain. The interface between the two domains is a key structural entity that governs gating. Molecular events in signal transduction at the interface are poorly defined because of its intrinsically dynamic nature combined with functional modulation by membrane lipid and water vestibules. Here we used electron paramagnetic resonance spectroscopy to delineate protein motions underlying Gloeobacter violaceus ligand-gated ion channel gating in a membrane environment and report the interface conformation in the closed and the desensitized states. Extensive intrasubunit interactions were observed in the closed state that are weakened upon desensitization and replaced by newer intersubunit contacts. Gating involves major rearrangements of the interfacial loops, accompanied by reorganization of the protein-lipid-water interface. These structural changes may serve as targets for modulation of gating by lipids, alcohols, and amphipathic drug molecules.     

Nesting ecology of the wasp Sceliphron destillatorium (Illiger, 1807) (Hymenoptera,Sphecidae) in the Crimea

The nests of Sceliphron destillatorium in the Crimea were mainly built in attic spaces of houses and in various uninhabited buildings, and consisted of 3–39 (on average 16.5) cells. Twelve species of spiders from 11 genera of 4 families with predomination of Araneidae and Oxyopidae were recorded as prey. One nest cell contained 4–13 (on average 7.9) spiders, mostly adult ones. Successful development of S. destillatorium progeny was recorded in 48.6% of the cells; 26.5% of the progeny died from parasites: Amobia pelopei (16.0%), Chrysis taczanovskyi (4.3%), and Melittobia acasta (6.2%); 24.9% of the progeny died for unknown causes at the egg (13.0%) or prepupal (11.9%) stage. Nests of 17 other wasp and bee species from the families Pompilidae (2 species), Vespidae (4), Colletidae (1), and Megachilidae (10 species) were found in abandoned nest cells of S. destillatorium. The abundance of S. destillatorium has noticeably decreased in the last ten years, possibly due to immigration of a congener, S. curvatum, which has more diverse trophic links and a significantly higher rate of nesting success.     

The effect of toxin-producing Fusarium fungi on behavior of the rice weevil Sitophilus oryzae (Coleoptera,Dryophthoridae)

The paper describes laboratory tests in which the behavior response of adult rice weevils Sitophilus oryzae L. to the presence of seven species of micromycetes of the genus Fusarium (F. graminearum, F. culmorum, F. cerealis, F. poae, F. sporotrichioides, F. langsethiae, and F. sibiricum; 3 strains for each species) infecting cereals was characterized. The chemicals of unkown structure, released by the fungi, can have both attractive and repellent effects on the weevils; in some cases a neutral response was observed. The strains of Fusarium species characterized as weak pathogens (F. langsethiae, F. poae, and F. sibiricum) in most cases stimulated attractive and neutral responses. Relatively strong pathogens (F. cerealis, F. culmorum, F. graminearum, and F. sporotrichioides) generally had a repellent effect. The results obtained are discussed in the context of possible relationships between Fusarium fungi and the rice weevil during their utilization of cereals as a shared food substrate.     

The use of muscle morphology of Chrysopolomidae (Lepidoptera) genitalic appendages in developing a family system

The male genitalia of Chrysopolomidae were found to include by nine pairs of muscles: m1, m2(10), m3(2), m4, m5(7), m6(5), m7(6), m8(3), m20, and the unpaired muscle m21, fully corresponding to their ground plan in Zygaenoidea. The archaic muscles m20 were found in both Chrysopolomidae and Limacodidae, for the first time for the superfamily Zygaenoidea. Muscles m3(2) and m4 in all the studied chrysopolomids are attached to the base of a gnathos-like complex sclerite, which proves its origin from the transtilla. The genital apparatus of Chrysopolomidae and its muscles are completely symmetrical. The bases of intravalval muscles m5(7) have moved from the sacculus to the juxta; this feature is not found in any other related family of the limacoid complex. The gnathos of Chrysopolomidae is reduced and functionally replaced by the transtilla separated from the valvae; some parts of the true gnathos may be incorporated in the gnathos-like structure of the transilla. A characteristic feature is the presence of strong muscles m3(2), which are reduced in all the studied limacodids. These muscles are running from the modified transtilla deep inside the uncus and provide not the abduction of the valvae but the depression of the uncus and the lifting of the arms of the transtilla. Thus, Chrysopolomidae are morphologically separated from Limacodidae; it is suggested that the former group should be treated as a separate family closely related to Limacodidae. The tribe Achroceridini is transferred from Chrysopolominae into Ectropinae based on the similar structure of the male genitalia and the presence of two pairs of spurs on the hind tibia.     

Antlions (Neuroptera,Myrmeleontidae) from ornithological traps on the Curonian Spit: A three-species community containing a new species

A mixed antlion community is recorded at the “Fringilla” Research Station, “Rybachii” Biological Station, Curonian Spit, Baltic Sea, Kaliningrad Province, Russia; the adults were captured using ornithological traps and the larvae were found on sand dunes around. The ratio of the larval numbers in the mixed colonies of Myrmeleon tschernovi sp. n., Myrmeleon formicarius L., and Euroleon nostras (Geoffr.) is 100: 3: 2. The new species is described, the other two are recorded in Kaliningrad Province for the first time. Morphologically, Myrmeleon tschernovi sp. n. is similar to Myrmeleon bore (Tjed.), being its neighbor in the Baltic Region and occupying its econiche. The most characteristic distinctions between these species are found in the male genitalia and in the larval head chaetotaxy and color pattern.     

Two New species of the dipteran genus Dolichopus Latreille (Diptera,Dolichopodidae) from Siberia and Mongolia

Two new species of the genus Dolichopus Latreille (Diptera, Dolichopodidae) are described from Mongolia and Siberia. Dolichopus tschernovi Negrobov, Barkalov et Selivanova, sp. n. is similar to Dolichopus bayaticus Negrobov, 1976, but differs in the presence of one seta on the hind metatarsus, the shorter 3rd antennal segment, and in the structure of the hypopygium. Dolichopus lenensis Negrobov, Barkalov et Selivanova, sp. n. resembles Dolichopus setitarsis Negrobov et Barkalov, 1977, but differs in the slightly widened 2nd–4th segments of the middle tarsus, in the presence of one seta on the hind metatarsus, and in the structure of the hypopygium. Drawings of the antennae, tarsi, and hypopygium of the new species are given. The holotypes of the new species are deposited in the Zoological Institute, the Russian Academy of Sciences (St. Petersburg).     

On the taxonomy of the Genus Coenosia Meigen, 1826 (Diptera,Muscidae) in the Russian Fauna,with a Description of Coenosia tschernovi sp. n.

Coenosia tschernovi sp. n. is described and illustrated from the Altai and Tuva republics. Coenosia nigrotincta Hennig, 1961 and C. xuei Cui et Li, 1996, are redescribed; the latter species is recorded from Russia for the first time. The new “apukaensis” group is erected for several similar Asian species. Coenosia altaica Sorokina, 2009 is considered a junior synonym of C. subgracilis Xue et Cui, 2001. Supplements to the key to the Siberian representatives of Coenosia Meigen, 1826 (Sorokina, 2009), to include new and recently found species, are given.     

Effects of Visual Feedback-Induced Variability on Motor Learning of Handrim Wheelchair Propulsion

BackgroundIt has been suggested that a higher intra-individual variability benefits the motor learning of wheelchair propulsion. The present study evaluated whether feedback-induced variability on wheelchair propulsion technique variables would also enhance the motor learning process. Learning was operationalized as an improvement in mechanical efficiency and propulsion technique, which are thought to be closely related during the learning process.Methods17 Participants received visual feedback-based practice (feedback group) and 15 participants received regular practice (natural learning group). Both groups received equal practice dose of 80 min, over 3 weeks, at 0.24 W/kg at a treadmill speed of 1.11 m/s. To compare both groups the pre- and post-test were performed without feedback. The feedback group received real-time visual feedback on seven propulsion variables with instruction to manipulate the presented variable to achieve the highest possible variability (1^st 4-min block) and optimize it in the prescribed direction (2^nd 4-min block). To increase motor exploration the participants were unaware of the exact variable they received feedback on. Energy consumption and the propulsion technique variables with their respective coefficient of variation were calculated to evaluate the amount of intra-individual variability.ResultsThe feedback group, which practiced with higher intra-individual variability, improved the propulsion technique between pre- and post-test to the same extent as the natural learning group. Mechanical efficiency improved between pre- and post-test in the natural learning group but remained unchanged in the feedback group.ConclusionThese results suggest that feedback-induced variability inhibited the improvement in mechanical efficiency. Moreover, since both groups improved propulsion technique but only the natural learning group improved mechanical efficiency, it can be concluded that the improvement in mechanical efficiency and propulsion technique do not always appear simultaneously during the motor learning process. Their relationship is most likely modified by other factors such as the amount of the intra-individual variability.     

Orexinergic Neurotransmission in Temperature Responses to Methamphetamine and Stress: Mathematical Modeling as a Data Assimilation Approach

Experimental Data

Orexinergic neurotransmission is involved in mediating temperature responses to methamphetamine (Meth). In experiments in rats, SB-334867 (SB), an antagonist of orexin receptors (OX1R), at a dose of 10 mg/kg decreases late temperature responses (t>60 min) to an intermediate dose of Meth (5 mg/kg). A higher dose of SB (30 mg/kg) attenuates temperature responses to low dose (1 mg/kg) of Meth and to stress. In contrast, it significantly exaggerates early responses (t<60 min) to intermediate and high doses (5 and 10 mg/kg) of Meth. As pretreatment with SB also inhibits temperature response to the stress of injection, traditional statistical analysis of temperature responses is difficult.

Mathematical Modeling

We have developed a mathematical model that explains the complexity of temperature responses to Meth as the interplay between excitatory and inhibitory nodes. We have extended the developed model to include the stress of manipulations and the effects of SB. Stress is synergistic with Meth on the action on excitatory node. Orexin receptors mediate an activation of on both excitatory and inhibitory nodes by low doses of Meth, but not on the node activated by high doses (HD). Exaggeration of early responses to high doses of Meth involves disinhibition: low dose of SB decreases tonic inhibition of HD and lowers the activation threshold, while the higher dose suppresses the inhibitory component. Using a modeling approach to data assimilation appears efficient in separating individual components of complex response with statistical analysis unachievable by traditional data processing methods.