The distribution and location of the symbiont Lagenophrys aselli on the freshwater isopod Asellus aquaticus

1. The distribution and location of the ciliated protozoan Lagenophrys aselli on the freshwater isopod Asellus aquaticus were studied in relation to water flow over the third pleopod surface. 2. At low densities L. aselli had a significant preference for the anterior centre of the pleopod; however, at the highest densities this preference was no longer significant. The distribution ranged from closer than random at low densities to further than random at the highest densities, and may have been a product of feeding and reproduction of L. aselli as well as the short intermoult period of the host. 3. An individual L. aselli has an effective area of both the lorica and the ciliated feeding disc. The ciliated feeding disc, when extended, may contribute to the presence of a small anterior–posterior gap being left between individuals.     

Conservation of <Emphasis Type="Italic">ParaHox</Emphasis> genes' function in patterning of the digestive tract of the marine gastropod <Emphasis Type="Italic">Gibbula varia</Emphasis>

Background  

Presence of all three ParaHox genes has been described in deuterostomes and lophotrochozoans, but to date one of these three genes, Xlox has not been reported from any ecdysozoan taxa and both Xlox and Gsx are absent in nematodes. There is evidence that the ParaHox genes were ancestrally a single chromosomal cluster. Colinear expression of the ParaHox genes in anterior, middle, and posterior tissues of several species studied so far suggest that these genes may be responsible for axial patterning of the digestive tract. So far, there are no data on expression of these genes in molluscs.     

The changes in the predatory behavior of the microturbellarian <Emphasis Type="Italic">Stenostomum sphagnetorum</Emphasis> on two species of toxin-secreting ciliates of the genus <Emphasis Type="Italic">Spirostomum</Emphasis>

It is known that the microturbellarian Stenostomum sphagnetorum, a common ciliate predator, is very sensitive against different types of toxins produced by other ciliates for chemical defense, and consequently, it is not able to capture and ingests these ciliates. In particular, when the predator tries to attack one of these toxin-secreting ciliates, it is forced to regurgitate the captured prey in response to the toxin discharged from the ciliates. In this study it is shown that after repeated attacks by S. sphagnetorum against two species of toxic ciliates (Spirostomum ambiguum and Spirostomum teres), the predator acquires a behavior of prey selection that leads to the exclusion of these ciliates among the possible prey and to the distinction between edible and inedible (toxic) ciliates. This learned behavior, which is maintained for days, is lost only after the asexual reproduction of the microturbellarian. In addition, S. sphagnetorum learns to recognize and avoid specimens of S. ambiguum and S. teres artificially deprived of their toxins, strongly suggesting that the toxins are not exclusively associated in the prey recognition of the microturbellarian.     

Study of the enhancer-blocking activities of new boundaries in the <Emphasis Type="Italic">bithorax</Emphasis> complex of <Emphasis Type="Italic">Drosophila melanogaster</Emphasis>

It was shown earlier that the Mcp, Fab-7, and Fab-8 boundaries of the bithorax complex contain insulators that effectively block the enhancers of the yellow and white genes. Other boundaries have not been studied so far. The recent mapping of binding sites for the insulator protein dCTCF in the regulatory regions of the bithorax complex genes permitted the Fab-3, Fab-4, and Fab-6 boundaries to be localized. Here, we showed that, despite the presence of dCTCF-binding sites, fragments of the Fab-3, Fab-4, and Fab-6 boundaries do not exhibit the properties of insulators in the model system with the yellow and white genes. Moreover, in some regions of the genome the Fab-4 and Fab-6 boundaries display the properties of silencers.     

Origin of the Genus <Emphasis Type="Italic">Homo</Emphasis>

The origin of the genus Homo in Africa signals the beginning of the shift from increasingly bipedal apes to primitive, large-brained, stone tool-making, meat-eaters that traveled far and wide. This early part of the human genus is represented by three species: Homo habilis, Homo rudolfensis, and Homo erectus. H. habilis is known for retaining primitive features that link it to australopiths and for being the first stone tool makers. Little is known about H. rudolfensis except that it had a relatively large brain and large teeth compared to H. habilis and that it overlapped in time and space with other early Homo. Our understanding of the paleobiology and evolution of the larger-brained H. erectus is enhanced due to its rich fossil record. H. erectus was the first obligate, fully committed biped, and with a body adapted for modern striding locomotion, it was also the first in the human lineage to disperse outside of Africa. The early members of the genus Homo are the first to tip the scale from the more apish side of our evolutionary history toward the more human one.     

Distribution of the ticks <Emphasis Type="Italic">Ixodes persulcatus</Emphasis> and <Emphasis Type="Italic">Ixodes pavlovskyi</Emphasis> on the boundary of the forest and forest-steppe zones in the Ob region

Surveys of ixodoid ticks were performed in Novosibirsk Province (Novosibirsk and Toguchin Districts) and in the vicinity of Akademgorodok (Novosibirsk) in 2009–2010. The abundance and distribution of ticks were assessed in 8 types of habitats. Ixodes persulcatus (Schulze, 1930) was collected by flagging in Novosibirsk and Toguchin Districts, with the highest densities of 19 ind./km being observed in habitats with small-leaved trees. Three species of ticks: Ixodes persulcatus, I. pavlovskyi (subspecies I. pavlovskyi occidentalis Filip. et Pan., 1998), and Dermacentor reticulatus (Fabricius, 1794) were recorded in a recreational forest of Akademgorodok. A high abundance (22 ind./km) of I. pavlovskyi was observed in pine forests subjected to considerable recreational load. The abundance of I. persulcatus was the highest in aspen-birch and birch-aspen forests. D. reticulatus was captured in pine forests and fallow lands, its abundance varying from 0.2 to 2 ind./km.     

A biometric study of some representatives of the subsection <Emphasis Type="Italic">Nivales</Emphasis> (Prantl) Luferov of the genus <Emphasis Type="Italic">Ranunculus</Emphasis> L. (Ranunculaceae)

The results of a study of morphological character variability in the populations of R. altaicus s. l., R. sulphureus subsp. exaltatus and R. schmakovii are presented. Univariate and multivariate analysis methods have been applied: a principal components method, discriminant and variance analysis. As a result, two Altai buttercup subspecies have been distinguished in the territory of the Altai mountains (R. altaicus subsp. altaicus, R. altaicus subsp. frigidus), as well as the new taxa R. sulphureus subsp. exaltatus and R. schmakovii     

Vegetation of the aquatic and marshland habitats in the Orava region,including the first records of <Emphasis Type="Italic">Potametum alpini,Potametum zizii</Emphasis> and <Emphasis Type="Italic">Ranunculo-Juncetum bulbosi</Emphasis> in the territory of Slovakia

The vegetation of the aquatic and marshland habitats of the Orava region (north of Slovakia) was studied in 2009, using traditional phytosociological methods. Sixteen aquatic and eighteen marsh plant communities were described within 96 phytosociological relevés by using TWINSPAN with the application of the dominance principle. Three associations, Potametum alpini, Potametum zizii and Ranunculo-Juncetum bulbosi, were found as new communities for Slovakia. Myriophylletum verticillati, Potametum nodosi, Potametum graminei and Alisma gramineum community were recorded in the northernmost localities in Slovakia. Among marsh communities, Calletum palustris is very rare, both in the Orava region and in Slovakia as a whole. According to Ellenberg’s indicator values (EIV), moisture was evaluated as the main ecological gradient. Plant communities are ordered along the first Detrended Correspodence Analysis (DCA) axis in a typical hydroseries (Potametea → Lemnetea → Phragmition communis → Phalaridion arundinaceae, Oenanthion aquaticae and Sparganio-Glycerion → Magnocaricion elatae). The second DCA axis was most correlated with EIV for nutrients. Among the five directly measured ecological characteristics (temperature, pH and conductivity of water, water depth, and substrate type), conductivity of water (0.44, P < 0.01) and substrate type (0.32, P < 0.05) were the statistically significant variables explaining the variability along the first DCA axis.     

PCR analysis of the wheat varieties and near-isogenic wheat lines with the use of allele-specific primers for the <Emphasis Type="Italic">Gli-1</Emphasis> and <Emphasis Type="Italic">Glu-3</Emphasis> loci

The allelic characteristics of Gli-A1, Gli-B1, Gli-D1 and Glu-A3 loci of 14 bread wheat varieties and 6 near-isogenic wheat lines derived from the Bezosta 1 variety were found by the use of PCR. The conformity between molecular-genetic and storage protein electrophoretic data was revealed: the GliA1.2 allele corresponds to the Gli-A1o and Gli-A1m allelic variants of gliadin blocks; the GliA1.1 PCR allele corresponds to the Gli-A1f, Gli-A1b and Gli-A1c variants of gliadin blocks; the GliB1.1 allele corresponds to the Gli-B1b and Gli-B1d allelic variants; and the GliB1.2 allele corresponds to the Gli-B1e, Gli-B1g and Gli-B1c variants. A new PCR allele with primers for marker GliB1.1 at the Gli-B1 locus in the GLI-B1-12 line (with the gliadin Gli-Blo block), which was generated from crossing of Bezosta 1 and the variety Levent, was detected.     

Effects of Bacillus thuringiensisδ-endotoxin-fed Helicoverpa armigera on the survival and development of the parasitoid Campoletis chlorideae

With the deployment of transgenic crops expressing δ‐endotoxins from Bacillus thuringiensis (Bt) for pest management, there is a need to generate information on the interaction of crop pests with their natural enemies that are important for regulation of pest populations. Therefore, we studied the effects of the Bt δ‐endotoxins Cry1Ab and Cry1Ac on the survival and development of the parasitoid Campoletis chlorideae Uchida (Hymenoptera: Ichneumonidae) reared on Helicoverpa armigera (Hübner) (Lepidoptera: Noctuidae) larvae fed on Bt toxin‐intoxicated artificial diet. The H. armigera larvae fed on artificial diet impregnated with Cry1Ab and Cry1Ac at LC₅₀ (effective concentration to kill 50% of the neonate H. armigera larvae) and ED₅₀ (effective concentration to cause a 50% reduction in larval weight) levels before and after parasitization resulted in a significant reduction in cocoon formation and adult emergence of C. chlorideae. Larval period of the parasitoid was prolonged by 2 days when fed on Bt‐intoxicated larvae. No adverse effects were observed on female fecundity. The observed effects appeared to be indirect in nature, because no Bt proteins were detected through enzyme‐linked immunosorbent assay in the C. chlorideae larvae, cocoons, or adults fed on Cry1Ab‐ or Cry1Ac‐treated H. armigera larvae. The effects of Bt toxin proteins on C. chlorideae were due to early mortality of H. armigera larvae, that is, before completion of parasitoid larval development.     

Evaluation of the use of <Emphasis Type="Italic">recN</Emphasis> sequence analysis in the phylogeny of the genus <Emphasis Type="Italic">Amycolatopsis</Emphasis>

Partial recN gene sequences (>1 kb) were obtained from 35 type strains of the genus Amycolatopsis. Phylogenetic trees were constructed to determine the effectiveness of using this gene to predict taxonomic relationships within the genus. The use of recN sequence analysis as an alternative to DNA–DNA hybridization (DDH) for distinguishing closely related species was also assessed. The recN based phylogeny mostly confirmed the conventional 16S rRNA and gyrB gene-based phylogenies and thus provides further support for these phylogenetic groupings. As is the case for the gyrB gene, pairwise recN sequence similarities cannot be used to predict the DNA relatedness between type strains but the recN genetic distance can be used as a means to assess quickly whether an isolate is likely to represent a new species in the genus Amycolatopsis. A recN genetic distance of >0.04 between two Amycolatopsis strains is proposed to provide a good indication that they belong to different species (and that polyphasic taxonomic characterization of the unknown strain is worth undertaking).     

Phylogeny and the Evolution of the <Emphasis Type="Italic">Amylase</Emphasis> Multigenes in the <Emphasis Type="Italic">Drosophila montium</Emphasis> Species Subgroup

Abstract To investigate the phylogenetic relationships and molecular evolution of α-amylase (Amy) genes in the Drosophila montium species subgroup, we constructed the phylogenetic tree of the Amy genes from 40 species from the montium subgroup. On our tree the sequences of the auraria, kikkawai, and jambulina complexes formed distinct tight clusters. However, there were a few inconsistencies between the clustering pattern of the sequences and taxonomic classification in the kikkawai and jambulina complexes. Sequences of species from other complexes (bocqueti, bakoue, nikananu, and serrata) often did not cluster with their respective taxonomic groups. This suggests that relationships among the Amy genes may be different from those among species due to their particular evolution. Alternatively, the current taxonomy of the investigated species is unreliable. Two types of divergent paralogous Amy genes, the so-called Amy1- and Amy3-type genes, previously identified in the D. kikkawai complex, were common in the montium subgroup, suggesting that the duplication event from which these genes originate is as ancient as the subgroup or it could even predate its differentiation. Thc Amy1-type genes were closer to the Amy genes of D. melanogaster and D. pseudoobscura than to the Amy3-type genes. In the Amy1-type genes, the loss of the ancestral intron occurred independently in the auraria complex and in several Afrotropical species. The GC content at synonymous third codon positions (GC3s) of the Amy1-type genes was higher than that of the Amy3-type genes. Furthermore, the Amy1-type genes had more biased codon usage than the Amy3-type genes. The correlations between GC3s and GC content in the introns (GCi) differed between these two Amy-type genes. These findings suggest that the evolutionary forces that have affected silent sites of the two Amy-type genes in the montium species subgroup may differ.     

Origin of the plague microbe <Emphasis Type="Italic">Yersinia pestis</Emphasis>: Structure of the process of speciation

The origin and evolution of the plague microbe Yersinia pestis are considered in the context of propositions of modern Darwinism. It was shown that the plague pathogen diverged from the pseudotuberculous microbe Yersinia pseudotuberculosis O:1b in the mountain steppe landscapes of Central Asia in the Sartan: 22000-15000 years ago. Speciation occurred in the tarbagan (Marmota sibirica)-flea (Oropsylla silantiewi) parasitic system. The structure of the speciation process included six stages: isolation, genetic drift, enhancement of intrapopulational polymorphism, the beginning of pesticin synthesis (genetic conflict and emergence of hiatus), specialization (stabilization of characteristics), and adaptive irradiation (transformation of the monotypic species Y. pestis tarbagani into a polytypic species). The scenario opens up wide prospects for construction of the molecular phylogeny of the plague microbe Y. pestis and for investigation of the biochemical and molecular-genetic aspects of “Darwinian” evolution of pathogens from many other nature-focal infections.     

Maturation of a eukaryotic cytochrome <Emphasis Type="Italic">c</Emphasis> in the cytoplasm of <Emphasis Type="Italic">Escherichia coli</Emphasis> without the assistance by a dedicated biogenesis apparatus

Maturation of c-type cytochromes involves the covalent and stereospecific enzymatic attachment of a heme b via thioether linkages to two conserved cysteines within apocytochromes. Horse cytochrome c is readily matured into its native holoform in the cytoplasm of E. coli when co-expressed with yeast cytochrome c heme lyase. Here we report the low yield formation of holocytochrome with covalently attached heme also in the absence of heme lyase. This is the first demonstration of in vivo maturation of a eukaryotic cytochrome c in a prokaryotic cytoplasm without the assistance by a dedicated enzymatic maturation system. The assembled cytochrome c can be oxidized by cytochrome c oxidase, indicating the formation of a functional protein. The absorption spectrum is typical of a low spin, six coordinated c-type heme. Nevertheless, minor spectral differences relative to the native cytochrome c, deviation of the midpoint reduction potential and slightly altered kinetic parameters of the interaction with cytochrome c oxidase emphasize the importance of cytochrome c heme lyase in folding cytochrome c into its native conformation.