The potential of Beauveria bassiana inoculum formulated into a polymeric matrix for a microbial control of spruce bark beetle

Two local strains of Beauveria bassiana originally isolated from naturally infected spruce bark beetles in Slovakia were tested for their virulence to Ips typographus (IT) and for their compatibility with a polymeric matrix composed of low-molecular polyethylene. Conidia could be homogenously immobilized in the low-molecular polyethylene matrix with no adverse effect on their viability and infectivity. At constant temperature (25°C), viability of immobilized conidial decreased only by 1–2% after 7 or 14 days when compared with non-formulated conidia. In field conditions, viability of conidia formulated in the matrix was even significantly higher than non-formulated conidia 35 days after their application in traps. Conidia incorporated into the polymeric matrix were infective to IT adults in laboratory bioassays. Mean values of LC₅₀ for native conidia (0.72–2.05?×?10⁶ conidia?ml^?1) and conidia immobilized in the polymeric matrix (0.64–1.03?×?10⁵ conidia?mm^?2) demonstrated high virulence. The efficacy of the local strains was significantly higher than that of B. bassiana strains from mycoinsecticides (Boverol^®, Botanigard^® ES and Naturalis-L^®). Results showed potential of this polymeric material for its use in microbial control of IT when mixed with conidia of B. bassiana.     

Invasive zebra mussel colonisation of invasive crayfish: a case study

We investigated the interaction between two invasive invertebrate species in a shallow Central European flooded sandpit: the epibiosis of Ponto-Caspian zebra mussels Dreissena polymorpha on the American crayfish Orconectes limosus. Between 2004 and 2005, we followed the seasonal variation in number and size of the mussels attached to crayfish bodies, and microhabitats preferred by mussels. The proportion of crayfish colonised by mussels varied seasonally: in spring and early summer it was consistently over 75%, afterwards it dropped temporarily due to loss of bivalves during the crayfish moult, and later increased again due to re-colonisation by often relatively large juvenile mussels. Three different pathways of mussel settlement on crayfish hosts are likely: (1) primary settlement of free-swimming pediveliger larvae; (2) secondary settlement of plantigrade mussels and juveniles; (3) active re-attachment of grown mussels from the substrate to crayfish. This epibiosis was promoted by lack of suitable substrates at the studied locality. Electronic supplementary material The online version of this article (doi: ) contains supplementary material, which is available to authorized users.     

Dynamics of Simian immunodeficiency virus-specific cytotoxic T-cell responses in tissues

Although the dynamics of human immunodeficiency virus and Simian immunodeficiency virus (SIV)-specific cytotoxic T cells (CTLs) have been well documented in the blood, little is known regarding CTL development in other tissues. In this study, seven Mamu-A*01+ macaques were inoculated with SIVmac. Two macaques were killed at 21 days of infection, and SIV gag p11C tetramer responses were measured in the blood, axillary and mesenteric lymph nodes, spleen, bone marrow, and thymus. Three with clinical signs of disease were killed and similarly examined. Four macaques were followed throughout disease progression, and intestinal biopsies and blood were examined at regular time points after inoculation. In animals followed prospectively, peak early tetramer responses were detected in the blood (3.9-19% of CD3+ CD8+ T cells) between day 14-21 post-inoculation (p.i.). After day 49, tetramer responses in the blood diminished and remained relatively stable through day 200, ranging from 0.7-6.5% of CD3+ CD8+ T cells. In contrast, tetramer-positive T cells increased in the intestine in later stages of infection (100-200 days p.i.) in all four infected animals (peak values from 5.3 to 28.8%). Percentages of tetramer-positive cells were consistently higher in the intestine than in the blood in all four animals after day 100. In animals with acquired immunodeficiency syndrome, percentages of CTL in tissues were variable, but were consistently higher in the intestine and spleen compared with blood. These data suggest that while high CTL responses develop at a similar rate, and magnitude in both peripheral and mucosal lymphoid tissues in primary SIV infection, mucosal CTL responses may predominate later in the course of the disease.     

Evaluation of different alpha-Galactosyl glycoconjugates for use in xenotransplantation

Porcine organs are rapidly rejected after transplantation into primate recipients due to the presence of preexisting immunoglobulins that bind to terminal galactose alpha1,3 galactose residues (alpha-galactosyl) present on porcine glycoproteins and glycolipids. Currently available immunosuppressive reagents have been largely ineffective at controlling the synthesis of these anti-Gal antibodies. Nonantigenic hapten polymers have been shown to be effective materials for blocking humoral immune responses in various model systems. We have developed a series of alpha-galactosyl glycoconjugate polymers and tested their ability to block anti-Gal antibody binding in vitro and in vivo. A galactose alpha1,3 galactose beta 1,4 GlcNAc trisaccharide free acid (TRFA) with a hexanoic acid spacer, containing five methylene groups and a carboxylic acid, was produced and coupled to a variety of polymeric backbones including dextran, branched poly(ethylene glycol) (PEG), and poly-L-lysine. The ability of monomeric TRFA and the alpha-galactosyl conjugates to block anti-Gal IgG and IgM binding was determined using a competition ELISA assay on defined HSA-Gal glycoconjugates and porcine microvascular endothelial cell substrates. We show that branched PEG carriers, with a TRFA sugar attached to each branch, exhibit enhanced antibody blocking ability compared to TRFA, but at higher target antigen densities these simple PEG conjugates are no more effective then an equivalent amount of TRFA in blocking anti-Gal IgM antibody interactions. In contrast, polymers of the branched PEG conjugates and linear conjugates made using dextran and poly-L-lysine were 2000 to 70000-fold more effective inhibitors of anti-Gal antibodies. In a study using nonhuman primates, a single dose infusion of polymeric PEG or dextran glycoconjugates dramatically reduced the level of circulating anti-Gal antibodies in cynomologus monkeys for at least 72 h. Glycoconjugates similar to these might be useful both to block anti-Gal interactions in vivo and to specifically control the induced anti-Gal immune response.     

Regulation of myocardial contractility and cell size by distinct PI3K-PTEN signaling pathways

The PTEN/PI3K signaling pathway regulates a vast array of fundamental cellular responses. We show that cardiomyocyte-specific inactivation of tumor suppressor PTEN results in hypertrophy, and unexpectedly, a dramatic decrease in cardiac contractility. Analysis of double-mutant mice revealed that the cardiac hypertrophy and the contractility defects could be genetically uncoupled. PI3Kalpha mediates the alteration in cell size while PI3Kgamma acts as a negative regulator of cardiac contractility. Mechanistically, PI3Kgamma inhibits cAMP production and hypercontractility can be reverted by blocking cAMP function. These data show that PTEN has an important in vivo role in cardiomyocyte hypertrophy and GPCR signaling and identify a function for the PTEN-PI3Kgamma pathway in the modulation of heart muscle contractility.     

Refined mapping of the gene causing familial mediterranean fever, by linkage and homozygosity studies

Familial Mediterranean fever (FMF) is an autosomal recessive disease characterized by attacks of fever and serosal inflammation; the biochemical basis is unknown. We recently reported linkage of the gene causing FMF (designated “MEF”) to two markers on chromosome 16p. To map MEF more precisely, we have now tested nine 16p markers. Two-point and multipoint linkage analysis, as well as a study of recombinant haplotypes, placed MEF between D16S94 and D16S80, a genetic interval of about 9 cM. We also examined rates of homozygosity for markers in this region, among offspring of consanguineous marriages. For eight of nine markers, the rate of homozygosity among 26 affected inbred individuals was higher than that among their 20 unaffected sibs. Localizing MEF more precisely on the basis of homozygosity rates alone would be difficult, for two reasons: First, the high FMF carrier frequency increases the chance that inbred offspring could have the disease without being homozygous by descent at MEF. Second, several of the markers in this region are relatively nonpolymorphic, with a high rate of homozygosity, regardless of their chromosomal location.     

Mammalian splicing factor SF1 interacts with SURP domains of U2 snRNP-associated proteins

Splicing factor 1 (SF1) recognizes the branch point sequence (BPS) at the 3′ splice site during the formation of early complex E, thereby pre-bulging the BPS adenosine, thought to facilitate subsequent base-pairing of the U2 snRNA with the BPS. The 65-kDa subunit of U2 snRNP auxiliary factor (U2AF65) interacts with SF1 and was shown to recruit the U2 snRNP to the spliceosome. Co-immunoprecipitation experiments of SF1-interacting proteins from HeLa cell extracts shown here are consistent with the presence of SF1 in early splicing complexes. Surprisingly almost all U2 snRNP proteins were found associated with SF1. Yeast two-hybrid screens identified two SURP domain-containing U2 snRNP proteins as partners of SF1. A short, evolutionarily conserved region of SF1 interacts with the SURP domains, stressing their role in protein–protein interactions. A reduction of A complex formation in SF1-depleted extracts could be rescued with recombinant SF1 containing the SURP-interaction domain, but only partial rescue was observed with SF1 lacking this sequence. Thus, SF1 can initially recruit the U2 snRNP to the spliceosome during E complex formation, whereas U2AF65 may stabilize the association of the U2 snRNP with the spliceosome at later times. In addition, these findings may have implications for alternative splicing decisions.     

The diet of the spiny-cheek crayfish Orconectes limosus in the Czech Republic

The composition of the diet of the invasive spiny-cheek crayfish Orconectes limosus was studied using qualitative and quantitative analyses of stomach contents. A total of 368 specimens collected in 2003–2005 and 2008 in Czech localities were examined, predominantly from the Labe (Elbe) and Vltava River basins. Food components were compared for three size classes of crayfish and both sexes. The following conclusions were reached: (1) the spiny-cheek crayfish is an omnivorous species consuming plants, animals and detritus; (2) quantitatively, the main food component of O. limosus is detritus, while the plant component was second; (3) O. limosus may swallow whole food particles up to 4 mm in size, and the bodies of small animals may sometimes be found undamaged in their stomachs.     

New information on the geographical distribution of <Emphasis Type="Italic">Piscicola brylinskae</Emphasis> Bielecki, 2001 (Hirudinea: Piscicolidae) in Poland and remarks on its systematic position

For the first time, Piscicola brylinskae was described from Lake Vechten in the village of Bunnik, near Utrecht — The Netherlands. Until now, P. brylinskae has been found in Poland in Lake Maróz and in the Łyna River near Olsztyn (the northern part of Warmian-Masurian voivodeship). Thanks to proper conservation the coloration of P. brylinskae was described for the first time. Applying 32 indexes resulted that P. brylinskae clustered to Caspiobdella fadejewi. Analysis based on 113 non-metric characteristics has shown that P. brylinskae is most similar to Piscicola margaritae. Though, P. brylinskae do not form with P. margaritae dichotomic branching nor with any other species from this cluster, it could confirm that it is an individual species of the Piscicola genus.