Foraminifers from the uppermost devonian and the dinantian of the rhenish massif (Federal Republic of Germany)

Foraminifers from typical Kulm environments are described from 4 localities at the eastern and northern border of the Rhenish Massif: aQuasiendothyra fauna of uppermost Devonian age (Famennian); a Chernyshinellinae fauna of the lower Dinantian Cf1 Zone (middle Tournaisian); upper Dinantian foraminifers from the Cf4δ to Cf6γ Zones (Middle and Upper Viséan). The foraminifer assemblages of the Cf6 Zone (V3b + c), in theGoniatites crenistria schmidtianus toNeoglyphioceras spirale Subzones, seem to be variegated in Germany and Belgium, but they are definitively poorer than contemporaneous faunes in the British Isles and the Russian Platform.     

Complete genomic sequence of the virulent Salmonella bacteriophage SP6

We report the complete genome sequence of enterobacteriophage SP6, which infects Salmonella enterica serovar Typhimurium. The genome contains 43,769 bp, including a 174-bp direct terminal repeat. The gene content and organization clearly place SP6 in the coliphage T7 group of phages, but there is approximately 5 kb at the right end of the genome that is not present in other members of the group, and the homologues of T7 genes 1.3 through 3 appear to have undergone an unusual reorganization. Sequence analysis identified 10 putative promoters for the SP6-encoded RNA polymerase and seven putative rho-independent terminators. The terminator following the gene encoding the major capsid subunit has a termination efficiency of about 50% with the SP6-encoded RNA polymerase. Phylogenetic analysis of phages related to SP6 provided clear evidence for horizontal exchange of sequences in the ancestry of these phages and clearly demarcated exchange boundaries; one of the recombination joints lies within the coding region for a phage exonuclease. Bioinformatic analysis of the SP6 sequence strongly suggested that DNA replication occurs in large part through a bidirectional mechanism, possibly with circular intermediates.     

Bacterial acyl-CoA mutase specifically catalyzes coenzyme B12-dependent isomerization of 2-hydroxyisobutyryl-CoA and (S)-3-hydroxybutyryl-CoA

Coenzyme B(12)-dependent acyl-CoA mutases are radical enzymes catalyzing reversible carbon skeleton rearrangements in carboxylic acids. Here, we describe 2-hydroxyisobutyryl-CoA mutase (HCM) found in the bacterium Aquincola tertiaricarbonis as a novel member of the mutase family. HCM specifically catalyzes the interconversion of 2-hydroxyisobutyryl- and (S)-3-hydroxybutyryl-CoA. Like isobutyryl-CoA mutase, HCM consists of a large substrate- and a small B(12)-binding subunit, HcmA and HcmB, respectively. However, it is thus far the only acyl-CoA mutase showing substrate specificity for hydroxylated carboxylic acids. Complete loss of 2-hydroxyisobutyric acid degradation capacity in hcmA and hcmB knock-out mutants established the central role of HCM in A. tertiaricarbonis for degrading substrates bearing a tert-butyl moiety, such as the fuel oxygenate methyl tert-butyl ether (MTBE) and its metabolites. Sequence analysis revealed several HCM-like enzymes in other bacterial strains not related to MTBE degradation, indicating that HCM may also be involved in other pathways. In all strains, hcmA and hcmB are associated with genes encoding for a putative acyl-CoA synthetase and a MeaB-like chaperone. Activity and substrate specificity of wild-type enzyme and active site mutants HcmA I90V, I90F, and I90Y clearly demonstrated that HCM belongs to a new subfamily of B(12)-dependent acyl-CoA mutases.     

Vascular targeting to the SST2 receptor improves the therapeutic response to near-IR two-photon activated PDT for deep-tissue cancer treatment

Background

Broader clinical acceptance of photodynamic therapy is currently hindered by (a) poor depth efficacy, and (b) predisposition towards establishment of an angiogenic environment during the treatment. Improved depth efficacy is being sought by exploiting the NIR tissue transparency window and by photo-activation using two-photon absorption (2PA). Here, we use two-photon activation of PDT sensitizers, untargeted and targeted to SST2 receptors or EGF receptors, to achieve deep tissue treatment.

Methods

Human tumor lines, positive or negative for SST2r expression were used, as well as murine 3LL cells and bovine aortic endothelial cells. Expression of SST2 receptors on cancer cells and tumor vasculature was evaluated in vitro and frozen xenograft sections. PDT effects on tumor blood flow were followed using in vivo scanning after intravenous injection of FITC conjugated dextran 150 K. Dependence of the PDT efficacy on the laser pulse duration was evaluated. Effectiveness of targeting to vascular SST2 receptors was compared to that of EGF receptors, or no targeting.

Results

Tumor vasculature stained for SST2 receptors even in tumors from SST2 receptor negative cell lines, and SST2r targeted PDT led to tumor vascular shutdown. Stretching the pulse from ~ 120 fs to ~ 3 ps led to loss of the PDT efficacy especially at greater depth. PDT targeted to SST2 receptors was much more effective than untargeted PDT or PDT targeted to EGF receptors.

General significance

The use of octreotate to target SST2 receptors expressed on tumor vessels is an excellent approach to PDT with few recurrences and some long term cures.     

Assortative mating among animals of captive and wild origin following experimental conservation releases

Captive breeding is a high profile management tool used for conserving threatened species. However, the inevitable consequence of generations in captivity is broad scale and often-rapid phenotypic divergence between captive and wild individuals, through environmental differences and genetic processes. Although poorly understood, mate choice preference is one of the changes that may occur in captivity that could have important implications for the reintroduction success of captive-bred animals. We bred wild-caught house mice for three generations to examine mating patterns and reproductive outcomes when these animals were simultaneously released into multiple outdoor enclosures with wild conspecifics. At release, there were significant differences in phenotypic (e.g. body mass) and genetic measures (e.g. G_st and F) between captive-bred and wild adult mice. Furthermore, 83% of offspring produced post-release were of same source parentage, inferring pronounced assortative mating. Our findings suggest that captive breeding may affect mating preferences, with potentially adverse implications for the success of threatened species reintroduction programmes.     

Tolerance of Listeria monocytogenes to Quaternary Ammonium Sanitizers Is Mediated by a Novel Efflux Pump Encoded by emrE

A novel genomic island (LGI1) was discovered in Listeria monocytogenes isolates responsible for the deadliest listeriosis outbreak in Canada, in 2008. To investigate the functional role of LGI1, the outbreak strain 08-5578 was exposed to food chain-relevant stresses, and the expression of 16 LGI1 genes was measured. LGI1 genes with putative efflux (L. monocytogenes emrE [emrE_Lm]), regulatory (lmo1851), and adhesion (sel1) functions were deleted, and the mutants were exposed to acid (HCl), cold (4°C), salt (10 to 20% NaCl), and quaternary ammonium-based sanitizers (QACs). Deletion of lmo1851 had no effect on the L. monocytogenes stress response, and deletion of sel1 did not influence Caco-2 and HeLa cell adherence/invasion, whereas deletion of emrE resulted in increased susceptibility to QACs (P < 0.05) but had no effect on the MICs of gentamicin, chloramphenicol, ciprofloxacin, erythromycin, tetracycline, acriflavine, and triclosan. In the presence of the QAC benzalkonium chloride (BAC; 5 μg/ml), 14/16 LGI1 genes were induced, and lmo1861 (putative repressor gene) was constitutively expressed at 4°C, 37°C, and 52°C and in the presence of UV exposure (0 to 30 min). Following 1 h of exposure to BAC (10 μg/ml), upregulation of emrE (49.6-fold), lmo1851 (2.3-fold), lmo1861 (82.4-fold), and sigB (4.1-fold) occurred. Reserpine visibly suppressed the growth of the ΔemrE_Lm strain, indicating that QAC tolerance is due at least partially to efflux activity. These data suggest that a minimal function of LGI1 is to increase the tolerance of L. monocytogenes to QACs via emrE_Lm. Since QACs are commonly used in the food industry, there is a concern that L. monocytogenes strains possessing emrE will have an increased ability to survive this stress and thus to persist in food processing environments.     

mTOR Inhibition Induces Compensatory,Therapeutically Targetable MEK Activation in Renal Cell Carcinoma

Rapamycin derivatives allosterically targeting mTOR are currently FDA approved to treat advanced renal cell carcinoma (RCC), and catalytic inhibitors of mTOR/PI3K are now in clinical trials for treating various solid tumors. We sought to investigate the relative efficacy of allosteric versus catalytic mTOR inhibition, evaluate the crosstalk between the mTOR and MEK/ERK pathways, as well as the therapeutic potential of dual mTOR and MEK inhibition in RCC. Pharmacologic (rapamycin and BEZ235) and genetic manipulation of the mTOR pathway were evaluated by in vitro assays as monotherapy as well as in combination with MEK inhibition (GSK1120212). Catalytic mTOR inhibition with BEZ235 decreased proliferation and increased apoptosis better than allosteric mTOR inhibition with rapamycin. While mTOR inhibition upregulated MEK/ERK signaling, concurrent inhibition of both pathways had enhanced therapeutic efficacy. Finally, primary RCC tumors could be classified into subgroups [(I) MEK activated, (II) Dual MEK and mTOR activated, (III) Not activated, and (IV) mTOR activated] based on their relative activation of the PI3K/mTOR and MEK pathways. Patients with mTOR only activated tumors had the worst prognosis. In summary, dual targeting of the mTOR and MEK pathways in RCC can enhance therapeutic efficacy and primary RCC can be subclassified based on their relative levels of mTOR and MEK activation with potential therapeutic implications.