Traits and evolution of wing venation pattern in paraneopteran insects

Two different patterns of wing venation are currently supposed to be present in each of the three orders of Paraneoptera. This is unlikely compared with the situation in other insects where only one pattern exists per order. We propose for all Paraneoptera a new and unique interpretation of wing venation pattern, assuming that the convex cubitus anterior gets fused with the common stem of median and radial veins at or very near to wing base, after separation from concave cubitus posterior, and re‐emerges more distally from R + M stem. Thereafter, the vein between concave cubitus posterior and CuA is a specialized crossvein called “cua‐cup,” proximally concave and distally convex. We show that despite some variations, that is, cua‐cup can vary from absent to hypertrophic; CuA can re‐emerge together with M or not, or even completely disappear, this new interpretation explains all situations among all fossil and recent paraneopteran lineages. We propose that the characters “CuA fused in a common stem with R and M”and “presence of specialized crossvein cua‐cup” are venation apomorphies that support the monophyly of the Paraneoptera. In the light of these characters, we reinterpret several Palaeozoic and early Mesozoic fossils that were ascribed to Paraneoptera, and confirm the attribution of several to this superorder as well as possible attribution of Zygopsocidae (Zygopsocus permianus Tillyard, 1935) as oldest Psocodea. We discuss the situation in extinct Hypoperlida and Miomoptera, suggesting that both orders could well be polyphyletic, with taxa related to Archaeorthoptera, Paraneoptera, or even Holometabola. The Carboniferous Protoprosbolidae is resurrected and retransferred into the Paraneoptera. The genus Lithoscytina is restored. The miomopteran Eodelopterum priscum Schmidt, 1962 is newly revised and considered as a fern pinnule. In addition, the new paraneopteran Bruayaphis oudardi gen. nov. et sp. nov. is described fromthe Upper Carboniferous of France (see Supporting Information). J. Morphol., 2012. © 2011 Wiley Periodicals, Inc.     

Easily available enzymes as natural retting agents

Easily available commercial enzymes currently have great potential in bast fibre processing and can be modified for different end uses. There are several new technologies using enzymes that are able to modify fibre parameters, achieve requested properties, improve processing results and are more beneficial to the ecology in the area of bast fibre processing and fabrics finishing. Enzymatic methods for retting of flax, "cottonisation" of bast fibres, hemp separation, and processing of flax rovings before wet spinning, etc., fall into this group of new technologies. Such enzymatic biotechnologies can provide benefits in textile, composite, reinforced plastic and other technical applications. Laboratory, pilot and industrial scale results and experiences have demonstrated the ability of selected enzymes to decompose interfibre-bonding layers based on pectin, lignin and hemicelluloses. Texazym SER spray is able to increase flax long fibre yields by more than 40%. Other enzymes in combination with mild mechanical treatment can replace aggressive and energy-intensive processing like Laroche "cottonisation". Texazym SCW and DLG pretreatments of flax rovings are presented.     

Is plasticity in mating preferences adapted to perceived exposure to pathogens?

Humans are unique among primates due to a lack of typical thermally insulating fur. The ectoparasite avoidance mediated by the mate choice hypothesis suggests that the loss of body hair reduces the risk of infection by ectoparasites and that the movement toward nudity may have been enforced by parasite-mediated sexual selection. In this study, we investigated two possible predictions of this hypothesis: (1) that preferences for hairless bodies increase with exposure to environmental pathogens and (2) that disgust sensitivity to the pathogens’ threat predicts the degree to which a woman will prefer hairless bodies. Using an experiment comparing the preferences of 88 women for shaved vs. hairy pictured versions of 20 male torsos, we found that exposure to the visual cues of pathogens does not predict preferences for a male chest nor does the individual disgust sensitivity to disease-related invertebrates. Overall, the results suggest that female perception of male trunk hair is not associated with a risk of contamination, which questions the salience of the ectoparasite avoidance hypothesis in explaining the loss of body hair in humans.     

Using the ratio of means as the effect size measure in combining results of microarray experiments

Background  

Development of efficient analytic methodologies for combining microarray results is a major challenge in gene expression analysis. The widely used effect size models are thought to provide an efficient modeling framework for this purpose, where the measures of association for each study and each gene are combined, weighted by the standard errors. A significant disadvantage of this strategy is that the quality of different data sets may be highly variable, but this information is usually neglected during the integration. Moreover, it is widely known that the estimated standard deviations are probably unstable in the commonly used effect size measures (such as standardized mean difference) when sample sizes in each group are small.     

Does Social Mating System Influence Nest Defence Behaviour in Great Reed Warbler (Acrocephalus arundinaceus) Males?

In birds with biparental care, males and females often conflict over how much care to provide to their offspring and it may be substantially influenced by increased level of polygamy. In accordance with sexual conflict theory, males of socially polygynous bird species provide much less care to their nestlings than do males of most socially monogamous species. Most of previous studies, however, have used feeding behaviour as an index for variations in male parental care only. However, this may be skewed if polygynous males compensate for lower feeding assistance through the provision of other parental care such as protection of nests from predators. In this paper, we examine nest defence behaviour in the facultatively polygynous great reed warbler with respect to sex and type of social mating system. We recorded latency to the first arrival, distance from the predator and defensive reaction of each parent towards a human intruder. Socially polygynous males with two simultaneously active nests defended primary females’ nests less vigorously than socially monogamous males, whereas no differences were found between monogamous and primary females. Generally, however, they took a bigger role in nest defence than males in all cases. Our results support an idea that sexual conflict is driven by polygamy and that type of social mating system can influence nest defence behaviour of facultatively polygynous birds. This finding should be taken into consideration when studying nest defence parental care in polygynous mating systems.     

Low inbreeding depression in a sexual trait in the stalk-eyed fly <Emphasis Type="Italic">Teleopsis dalmanni</Emphasis>

The genic capture hypothesis implies that the expression of sexual ornaments largely depends on genes affecting resource acquisition and use. The ornaments should thus show high degree of directional dominance typical of life-history traits, and consequently, they should be severely affected by inbreeding. Here we investigated the effect of inbreeding on a sexual ornament (male eyespan) in stalk-eyed fly, Teleopsis dalmanni. For comparison, we also measured inbreeding depression in non-sexual morphological traits: female eyespan as well as wing and thorax lengths in both sexes. Both eyespan, and other morphological traits we measured, showed significant inbreeding depression. In accord with predictions of genic capture hypothesis, male eyespan did decrease under inbreeding significantly more than female eyespan. However, the decline in male eyespan was fully explained by overall decline in body length. Moreover, the magnitude of inbreeding depression in male eyespan was considerably lower than that typically observed for life-histories; in fact, it fitted within the range typically characterizing morphological traits. We therefore conclude that our results provide weak support for genic capture hypothesis.     

The impact of Ivan Málek’s continuous culture concept on bioprocessing

This paper summarizes research results and their industrial applications obtained by continuous culture in the former Czechoslovakia. Past achievements as well as recent trends and developments worldwide are presented. The term “Prague School of continuous culture” is put forward and its international activity is outlined. The impact of this school was pervasive across the entire field of applied microbiology and biotechnology in Czechoslovakia and, perhaps, even beyond the country's boarders. Continuous culture is a very mature field, and since its establishment it has become a powerful research tool. The present activity in this field amounts to a renaissance of continuous culture, emphasizing new dimensions in bioinformatics and systems biology.     

Identification of distinct gamma-secretase complexes with different APH-1 variants

The gamma-secretase complex catalyzes the final intramembraneous cleavage of the beta-amyloid precursor protein, liberating the neurotoxic amyloid beta-peptide implicated in Alzheimer's disease. Apart from the catalytic subunit presenilin (PS), three additional subunits, nicastrin, APH-1, and PEN-2, have been identified. In mammals, two PS homologues, PS1 and PS2, which are part of distinct gamma-secretase complexes, exist. Likewise, two APH-1 homologues, APH-1a and APH-1b, have been identified. Furthermore, two APH-1a splice forms, APH-1aS and APH-1aL, have been reported. Here we show that both APH-1a splice forms and APH-1b are expressed in peripheral and neuronal cells. APH-1aS, APH-1aL, and APH-1b form separate, proteolytically active gamma-secretase complexes containing either one of the two PSs. Deficiency of APH-1a caused a decrease in nicastrin, PS, and PEN-2 levels and an increase in the levels of APH-1b, whereas deficiency of APH-1b did not affect the levels of APH-1a or the other complex components. Consistent with this finding, we found that deficiency of APH-1a was associated with reduced gamma-secretase activity, whereas deficiency of APH-1b was not. Thus, APH-1b gamma-secretase complexes may fulfill redundant functions. Taken together, our results suggest that, dependent on the tissue expression of the individual subunits, six distinct gamma-secretase complexes composed of the known subunits can exist in human cells.     

Catalytic mechanism of the maloalkane dehalogenase LinB from Sphingomonas paucimobilis UT26

Haloalkane dehalogenases are bacterial enzymes capable of carbon-halogen bond cleavage in halogenated compounds. To obtain insights into the mechanism of the haloalkane dehalogenase from Sphingomonas paucimobilis UT26 (LinB), we studied the steady-state and presteady-state kinetics of the conversion of the substrates 1-chlorohexane, chlorocyclohexane, and bromocyclohexane. The results lead to a proposal of a minimal kinetic mechanism consisting of three main steps: (i) substrate binding, (ii) cleavage of the carbon-halogen bond with simultaneous formation of an alkyl-enzyme intermediate, and (iii) hydrolysis of the alkyl-enzyme intermediate. Release of both products, halide and alcohol, is a fast process that was not included in the reaction mechanism as a distinct step. Comparison of the kinetic mechanism of LinB with that of haloalkane dehalogenase DhlA from Xantobacter autotrophicus GJ10 and the haloalkane dehalogenase DhaA from Rhodococcus rhodochrous NCIMB 13064 shows that the overall mechanisms are similar. The main difference is in the rate-limiting step, which is hydrolysis of the alkylenzyme intermediate in LinB, halide release in DhlA, and liberation of an alcohol in DhaA. The occurrence of different rate-limiting steps for three enzymes that belong to the same protein family indicates that extrapolation of this important catalytic property from one enzyme to another can be misleading even for evolutionary closely related proteins. The differences in the rate-limiting step were related to: (i) number and size of the entrance tunnels, (ii) protein flexibility, and (iii) composition of the halide-stabilizing active site residues based on comparison of protein structures.