Characterization of Bacteriophages of Pseudomonas syringae pv. tomato

Bacteriophages from supernatants of the plant pathogenic bacteria Pseudomonas syringae pv. tomato (P. tomato) were isolated, enriched, and purified by density block centrifugation in cesium chloride (CsCl) step gradients. The DNA from purified phage was isolated and digested with the restriction endonucleases EcoRl or HindIII. Three different DNA fingerprint patterns were determined indicating 3 unique phage isolates. Genome sizes of the phage ranged from 40 to 52 kilobases (kB). Buoyant densities of phage particles in CsCI varied from 1.36 to 1.51 glml. Electron microscopy revealed a single morphological type with an elongated polyhedral head and a long tail indicating the family Siphovirida

Kinases and protein phosphorylation as regulators of steroid hormone action

Although the primary signal for the activation of steroid hormone receptors is binding of hormone, there is increasing evidence that the activities of cell signaling pathways and the phosphorylation status of these transcription factors and their coregulators determine the overall response to the hormone. In some cases, enhanced cell signaling is sufficient to cause activation of receptors in medium depleted of steroids. Steroid receptors are targets for multiple kinases. Many of the phosphorylation sites contain Ser/Thr-Pro motifs implicating proline-directed kinases such as the cyclin-dependent kinases and the mitogen-activated kinases (MAPK) in receptor phosphorylation. Although some sites are constitutively phosphorylated, others are phosphorylated in response to hormone. Still others are only phosphorylated in response to specific cell signaling pathways. Phosphorylation of specific sites has been implicated not only in overall transcriptional activity, but also in nuclear localization, protein stability, and DNA binding. The studies of the roles of phosphorylation in coregulator function are more limited, but it is now well established that many of them are highly phosphorylated and that phosphorylation regulates their function. There is good evidence that some of the phosphorylation sites in the receptors and coregulators are targets of multiple signaling pathways. Individual sites have been associated both with functions that enhance the activity of the receptor, as well as with functions that inhibit activity. Thus, the specific combinations of phosphorylations of the steroid receptor combined with the expression levels and phosphorylation status of coregulators will determine the genes regulated and the biological response

Difficulties when Assessing Birdsong Learning Programmes under Field Conditions: A Re-Evaluation of Song Repertoire Flexibility in the Great Tit

There is a remarkable diversity of song-learning strategies in songbirds. Establishing whether a species is closed- or open-ended is important to be able to interpret functional and evolutionary consequences of variation in repertoire size. Most of our knowledge regarding the timing of vocal learning is based on laboratory studies, despite the fact that these may not always replicate the complex ecological and social interactions experienced by birds in the wild. Given that field studies cannot provide the experimental control of laboratory studies, it may not be surprising that species such as the great tit that were initially assumed to be closed-ended learners have later been suggested to be open-ended learners. By using an established colour-ringed population, by following a standardized recording protocol, and by taking into account the species' song ecology (using only recordings obtained during peak of singing at dawn), we replicated two previous studies to assess song repertoire learning and flexibility in adult wild great tits elicited by social interactions. First, we performed a playback experiment to test repertoire plasticity elicited by novel versus own songs. Additionally, in a longitudinal study, we followed 30 males in two consecutive years and analysed whether new neighbours influenced any change in the repertoire. Contrary to the previous studies, song repertoire size and composition were found to be highly repeatable both between years and after confrontation with a novel song. Our results suggest that great tits are closed-ended learners and that their song repertoire probably does not change during adulthood. Methodological differences that may have led to an underestimation of the repertoires or population differences may explain the discrepancy in results with previous studies. We argue that a rigorous and standardized assessment of the repertoire is essential when studying age- or playback-induced changes in repertoire size and composition under field conditions

A reafferent and feed-forward model of song syntax generation in the Bengalese finch

Adult Bengalese finches generate a variable song that obeys a distinct and individual syntax. The syntax is gradually lost over a period of days after deafening and is recovered when hearing is restored. We present a spiking neuronal network model of the song syntax generation and its loss, based on the assumption that the syntax is stored in reafferent connections from the auditory to the motor control area. Propagating synfire activity in the HVC codes for individual syllables of the song and priming signals from the auditory network reduce the competition between syllables to allow only those transitions that are permitted by the syntax. Both imprinting of song syntax within HVC and the interaction of the reafferent signal with an efference copy of the motor command are sufficient to explain the gradual loss of syntax in the absence of auditory feedback. The model also reproduces for the first time experimental findings on the influence of altered auditory feedback on the song syntax generation, and predicts song- and species-specific low frequency components in the LFP. This study illustrates how sequential compositionality following a defined syntax can be realized in networks of spiking neurons

RUNX3 Regulates Intercellular Adhesion Molecule 3 (ICAM-3) Expression during Macrophage Differentiation and Monocyte Extravasation

The adhesion molecule ICAM-3 belongs to the immunoglobulin gene superfamily and functions as a ligand for the β2 integrins LFA-1, Mac-1 and αdβ2. The expression of ICAM-3 is restricted to cells of the hematopoietic lineage. We present evidences that the ICAM-3 gene promoter exhibits a leukocyte-specific activity, as its activity is significantly higher in ICAM-3+ hematopoietic cell lines. The activity of the ICAM-3 gene promoter is dependent on the occupancy of RUNX cognate sequences both in vitro and in vivo, and whose integrity is required for RUNX responsiveness and for the cooperative actions of RUNX with transcription factors of the Ets and C/EBP families. Protein analysis revealed that ICAM-3 levels diminish upon monocyte-derived macrophage differentiation, monocyte transendothelial migration and dendritic cell maturation, changes that correlate with an increase in RUNX3. Importantly, disruption of RUNX-binding sites led to enhanced promoter activity, and small interfering RNA-mediated reduction of RUNX3 expression resulted in increased ICAM-3 mRNA levels. Altogether these results indicate that the ICAM-3 gene promoter is negatively regulated by RUNX transcription factors, which contribute to the leukocyte-restricted and the regulated expression of ICAM-3 during monocyte-to-macrophage differentiation and monocyte extravasation

Genome-Wide Progesterone Receptor Binding: Cell Type-Specific and Shared Mechanisms in T47D Breast Cancer Cells and Primary Leiomyoma Cells

Progesterone, via its nuclear receptor (PR), exerts an overall tumorigenic effect on both uterine fibroid (leiomyoma) and breast cancer tissues, whereas the antiprogestin RU486 inhibits growth of these tissues through an unknown mechanism. Here, we determined the interaction between common or cell-specific genome-wide binding sites of PR and mRNA expression in RU486-treated uterine leiomyoma and breast cancer cells.ChIP-sequencing revealed 31,457 and 7,034 PR-binding sites in breast cancer and uterine leiomyoma cells, respectively; 1,035 sites overlapped in both cell types. Based on the chromatin-PR interaction in both cell types, we statistically refined the consensus progesterone response element to G•ACA• • •TGT•C. We identified two striking differences between uterine leiomyoma and breast cancer cells. First, the cis-regulatory elements for HSF, TEF-1, and C/EBPα and β were statistically enriched at genomic RU486/PR-targets in uterine leiomyoma, whereas E2F, FOXO1, FOXA1, and FOXF sites were preferentially enriched in breast cancer cells. Second, 51.5% of RU486-regulated genes in breast cancer cells but only 6.6% of RU486-regulated genes in uterine leiomyoma cells contained a PR-binding site within 5 kb from their transcription start sites (TSSs), whereas 75.4% of RU486-regulated genes contained a PR-binding site farther than 50 kb from their TSSs in uterine leiomyoma cells. RU486 regulated only seven mRNAs in both cell types. Among these, adipophilin (PLIN2), a pro-differentiation gene, was induced via RU486 and PR via the same regulatory region in both cell types.Our studies have identified molecular components in a RU486/PR-controlled gene network involved in the regulation of cell growth, cell migration, and extracellular matrix function. Tissue-specific and common patterns of genome-wide PR binding and gene regulation may determine the therapeutic effects of antiprogestins in uterine fibroids and breast cancer

Making sense of diabetes medication decisions: a mixed methods cluster randomized trial using a conversation aid intervention.

PURPOSE: To determine the effectiveness of a shared decision-making (SDM) tool versus guideline-informed usual care in translating evidence into primary care, and to explore how use of the tool changed patient perspectives about diabetes medication decision making. METHODS: In this mixed methods multicenter cluster randomized trial, we included patients with type 2 diabetes mellitus and their primary care clinicians. We compared usual care with or without a within-encounter SDM conversation aid. We assessed participant-reported decisions made and quality of SDM (knowledge, satisfaction, and decisional conflict), clinical outcomes, adherence, and observer-based patient involvement in decision-making (OPTION12-scale). We used semi-structured interviews with patients to understand their perspectives. RESULTS: We enrolled 350 patients and 99 clinicians from 20 practices and interviewed 26 patients. Use of the conversation aid increased post-encounter patient knowledge (correct answers, 52% vs. 45%, p = 0.02) and clinician involvement of patients (Mean between-arm difference in OPTION12, 7.3 (95% CI 3, 12); p = 0.003). There were no between-arm differences in treatment choice, patient or clinician satisfaction, encounter length, medication adherence, or glycemic control. Qualitative analyses highlighted differences in how clinicians involved patients in decision making, with intervention patients noting how clinicians guided them through conversations using factors important to them. CONCLUSIONS: Using an SDM conversation aid improved patient knowledge and involvement in SDM without impacting treatment choice, encounter length, medication adherence or improved diabetes control in patients with type 2 diabetes. Future interventions may need to focus specifically on patients with signs of poor treatment fit. CLINICAL TRIAL REGISTRATION: ClinicalTrial.gov: NCT01502891

Rapid Effects of Hearing Song on Catecholaminergic Activity in the Songbird Auditory Pathway

Catecholaminergic (CA) neurons innervate sensory areas and affect the processing of sensory signals. For example, in birds, CA fibers innervate the auditory pathway at each level, including the midbrain, thalamus, and forebrain. We have shown previously that in female European starlings, CA activity in the auditory forebrain can be enhanced by exposure to attractive male song for one week. It is not known, however, whether hearing song can initiate that activity more rapidly. Here, we exposed estrogen-primed, female white-throated sparrows to conspecific male song and looked for evidence of rapid synthesis of catecholamines in auditory areas. In one hemisphere of the brain, we used immunohistochemistry to detect the phosphorylation of tyrosine hydroxylase (TH), a rate-limiting enzyme in the CA synthetic pathway. We found that immunoreactivity for TH phosphorylated at serine 40 increased dramatically in the auditory forebrain, but not the auditory thalamus and midbrain, after 15 min of song exposure. In the other hemisphere, we used high pressure liquid chromatography to measure catecholamines and their metabolites. We found that two dopamine metabolites, dihydroxyphenylacetic acid and homovanillic acid, increased in the auditory forebrain but not the auditory midbrain after 30 min of exposure to conspecific song. Our results are consistent with the hypothesis that exposure to a behaviorally relevant auditory stimulus rapidly induces CA activity, which may play a role in auditory responses

Unstable neurons underlie a stable learned behavior

Motor skills can be maintained for decades, but the biological basis of this memory persistence remains largely unknown. The zebra finch, for example, sings a highly stereotyped song that is stable for years, but it is not known whether the precise neural patterns underlying song are stable or shift from day to day. Here we demonstrate that the population of projection neurons coding for song in the premotor nucleus, HVC, change from day to day. The most dramatic shifts occur over intervals of sleep. In contrast to the transient participation of excitatory neurons, ensemble measurements dominated by inhibition persist unchanged even after damage to downstream motor nerves. These observations offer a principle of motor stability: spatiotemporal patterns of inhibition can maintain a stable scaffold for motor dynamics while the population of principal neurons that directly drive behavior shift from one day to the next