The rockefeller university

To ensure equal replication of the genome in every eukaryotic cell cycle, replication origins fire only once each S phase and do not fire after passive replication. Failure in these controls can lead to local amplification, contributing to genome instability and the development of cancer. To identify features of replication origins important for such amplification, we have investigated origin firing and local genome amplification in the presence of excess helicase loaders Cdc18 and Cdt1 in fission yeast. We find that S phase controls are attenuated and coordination of origin firing is lost, resulting in local amplification. Specific origins are necessary for amplification but act only within a permissive chromosomal context. Origins associated with amplification are highly AT-rich, fire efficiently and early during mitotic S phase, and are located in large intergenic regions. We propose that these features predispose replication origins to re-fire within a single S phase, or to remain active after passive replication.

The potential of a severe influenza pandemic necessitates the development of an organized, rational plan for continued laboratory animal facility operation without compromise of the welfare of animals. A comprehensive laboratory animal program pandemic response plan was integrated into a university-wide plan. Preparation involved input from all levels of organizational hierarchy including the IACUC. Many contingencies and operational scenarios were considered based on the severity and duration of the influenza pandemic. Trigger points for systematic action steps were based on the World Health Organization's phase alert criteria. One extreme scenario requires hibernation of research operations and maintenance of reduced numbers of laboratory animal colonies for a period of up to 6 mo. This plan includes active recruitment and cross-training of volunteers for essential personnel positions, protective measures for employee and family health, logistical arrangements for delivery and storage of food and bedding, the removal of waste, and the potential for euthanasia. Strategies such as encouraging and subsidizing cryopreservation of unique strains were undertaken to protect valuable research assets and intellectual property. Elements of this plan were put into practice after escalation of the pandemic alerts due to influenza A (H1N1) in April 2009.

P>Prey species commonly use predator-released kairomones (PRKs) to detect risk of predation, yet the chemical identity of PRKs remains elusive. Chemical identification of PRKs will facilitate the study of predator-prey interactions and the risk of predation, and when the prey are pests, will potentially provide environmentally friendly means of pest control. In temporary pools of the Mediterranean and Middle East, larvae of the mosquito Culiseta longiareolata Macquart are highly vulnerable to the common predatory backswimmer, Notonecta maculata Fabricius. We demonstrate that N. maculata releases two hydrocarbons, n-heneicosane and n-tricosane, which repel ovipositing females of C. longiareolata. In behavioural tests with environmentally relevant chemical concentrations in outdoor mesocosm experiments, the repellent effects of the two compounds were additive at the tested concentrations.

Background: The gamma-aminobutyric acid (GABA) Type A receptor deficits that are induced by global or forebrain-specific heterozygous inactivation of the gamma 2 subunit gene in mouse embryos result in behavior indicative of trait anxiety and depressive states. By contrast, a comparable deficit that is delayed to adolescence is without these behavioral consequences. Here we characterized gamma 2-deficient mice with respect to hypothalamic-pituitary-adrenal (HPA) axis abnormalities and antidepressant drug responses. Methods: We analyzed the behavioral responses of gamma 2(+/-) mice to desipramine and fluoxetine in novelty suppressed feeding, forced swim, tail suspension, and sucrose consumption tests as well as GABA(A) receptor deficit- and antidepressant drug treatment-induced alterations in serum corticosterone. Results: Baseline corticosterone concentrations in adult gamma 2-deficient mice were elevated independent of whether the genetic lesion was induced during embryogenesis or delayed to adolescence. However, the manifestation of anxious-depressive behavior in different gamma 2-deficient mouse lines was correlated with early onset HPA axis hyperactivity during postnatal development. Chronic but not subchronic treatment of gamma 2(+/-) mice with fluoxetine or desipramine normalized anxiety-like behavior in the novelty suppressed feeding test. Moreover, desipramine had antidepressant-like effects in that it normalized HPA axis function and depression-related behavior of gamma 2(+/-) mice in the forced swim, tail suspension, and sucrose consumption tests. By contrast, fluoxetine was ineffective as an antidepressant and failed to normalize HPA axis function. Conclusions: Developmental deficits in GABAergic inhibition in the forebrain cause behavioral and endocrine abnormalities and selective antidepressant drug responsiveness indicative of anxious-depressive disorders such as melancholic depression, which are frequently characterized by HPA axis hyperactivity and greater efficacy of desipramine versus fluoxetine.

Elevated levels of prostaglandins (PG) have been detected in the skin following UV radiation (UVR). PGs play an important role in mediating both the acute and the chronic consequences of UVR exposure. UVR-mediated induction of cyclooxygenase-2 (COX-2) contributes to increased PG synthesis. In theory, reduced catabolism might also contribute to increased PG levels. 15-Hydroxyprostaglandin deyhdrogenase (15-PGDH), a tumor suppressor gene, plays a major role in PG catabolism. In this study, we investigated whether UVR exposure suppressed 15-PGDH while inducing COX-2 in keratinocytes and in human skin. UVR exposure caused dose-dependent induction of COX-2, suppression of 15-PGDH, and increased prostaglandin E2 (PGE2) production in HaCaT cells. Exposure to UVR suppressed the transcription of 15-PGDH, resulting in reduced 15-PGDH mRNA, protein, and enzyme activities. UVR exposure induced Slug, a repressive transcription factor that bound to the 15-PGDH promoter. Silencing Slug blocked UVR-mediated downregulation of 15-PGDH. The effects of UVR were also evaluated in the Epi-Derm skin model, a three-dimensional model of human epidermis. Here too, COX-2 levels were induced and 15-PGDH levels suppressed following UVR exposure. Next, the effects of UVR were evaluated in human subjects. UVR treatment induced COX-2 while suppressing 15-PGDH mRNA in the skin of 9 of 10 subjects. Collectively, these data suggest that reduced expression of 15-PGDH contributes to the elevated levels of PGs found in the skin following UVR exposure. Possibly, agents that prevent UVR-mediated downregulation of 15-PGDH will affect the acute or the long-term consequences of UVR exposure, including nonmelanoma skin cancer. Cancer Prev Res; 3(9); 1104-11. (C) 2010 AACR.

Hudspeth AJ, Julicher F, Martin P. A critique of the critical cochlea: Hopf-a bifurcation-is better than none. J Neurophysiol 104: 1219-1229, 2010. First published June 10, 2010; doi:10.1152/jn.00437.2010. The sense of hearing achieves its striking sensitivity, frequency selectivity, and dynamic range through an active process mediated by the inner ear's mechanoreceptive hair cells. Although the active process renders hearing highly nonlinear and produces a wealth of complex behaviors, these various characteristics may be understood as consequences of a simple phenomenon: the Hopf bifurcation. Any critical oscillator operating near this dynamic instability manifests the properties demonstrated for hearing: amplification with a specific form of compressive nonlinearity and frequency tuning whose sharpness depends on the degree of amplification. Critical oscillation also explains spontaneous otoacoustic emissions as well as the spectrum and level dependence of the ear's distortion products. Although this has not been realized, several valuable theories of cochlear function have achieved their success by incorporating critical oscillators.

We present results of a search for anomalous production of two photons together with an electron, muon, tau lepton, missing transverse energy, or jets using p (p) over bar collision data from 1.1-2.0 fb(-1) of integrated luminosity collected by the Collider Detector at Fermilab (CDF). The event yields and kinematic distributions are examined for signs of new physics without favoring a specific model of new physics. The results are consistent with the standard model expectations. The search employs several new analysis

Bulk water has three phases: solid, liquid and vapour. In addition to undergoing a phase transition (of the first order) between them, liquid and vapour can deform continuously into each other without crossing a transition line-in other words, there is no intrinsic distinction between the two phases. Hence, the first-order line of the liquid-vapour phase transition should terminate at a critical point. In contrast, the first-order transition line between solid and liquid is believed to persist indefinitely without terminating at a critical point(1). In recent years, however, it was reported that inside carbon nanotubes, freezing of water may occur continuously as well as discontinuously through a first-order phase transition(2). Here we present simulation results for water in a quasi-two-dimensional hydrophobic nanopore slit, which are consistent with the idea that water may freeze by means of both first-order and continuous phase transitions. Our results lead us to hypothesize the existence of a connection point at which first-order and continuous transition lines meet(3,4).

Patients with Mendelian susceptibility to mycobacterial diseases (MSMD) mainly suffer from Mycobacterium and Salmonella infections, which are due to mutations in genes controlling the interleukin (IL)-12/ IL-23-dependent IFN-gamma production. We performed a molecular diagnosis in two Mexican patients with persistent mycobacterial infections. Patients 1 (P1) and 2 (P2) from two unrelated, non-consanguineous families from two villages near Mexico City developed bacille Calmette-Guerin (BCG) disease secondary to vaccination; patients and their families were studied at the immunological level for production and response to IFN-gamma. The beta 1 subunit of the IL-12 receptor (encoded by the IL12RB1 gene) was not expressed in cells from P1 or P2, or in two siblings of P1. Sequencing of the IL12RB1 gene showed the same point mutation 1791+2 T>G, homozygous in patients and heterozygous in parents. P1 and P2 died at the ages of 4 and 16 years, respectively, with disseminated and uncontrolled BCG disease and with Candida albicans infections in spite of multiple anti-mycobacterial drug treatments. One of P2's siblings also died following disseminated mycobacterial infection secondary to BCG vaccination. These are the first cases in Mexico of patients with BCG disease traced to a mutation in the IL12RB1 gene, with a fatal outcome. Doctors must be alert to the adverse reactions to BCG vaccination and to persistent Mycobacterium infections, and in such cases should investigate possible mutations in the genes of the IL-12/IL-23-IFN-gamma axis. (C) 2010 International Society for Infectious Diseases. Published by Elsevier Ltd. All rights reserved.

Culture independent approaches for accessing small molecules produced by uncultured bacteria are often hampered by the inability to easily clone environmental DNA (eDNA) fragments large enough to capture intact biosynthetic gene clusters that can be used in heterologous expression studies. Here we show that homology screening of eDNA megalibraries for clones containing natural product biosynthetic genes, coupled with transformation-assisted recombination (TAR) in yeast, can be used to access large, functionally intact, natural product gene clusters from the environment. The eDNA derived gene cluster reported here was functionally reconstructed from two overlapping cosmid clones using TAR. The isolation and structure elucidation of three new fluostatins (F, G, and H) produced by this TAR reconstructed gene cluster is described.