Cysteinyl-tRNA Deacylation Can Be Uncoupled from Protein Synthesis

Aminoacyl-tRNA synthetases (ARSs) are critical components of protein translation, providing ribosomes with aminoacyl-tRNAs. In return, ribosomes release uncharged tRNAs as ARS substrates. Here, we show that tRNA deacylation can be uncoupled from protein synthesis in an amino acid specific manner. While tRNAs coupled to radiolabeled Met, Leu Lys, or Ser are stable in cells following translation inhibition with arsenite, radiolabeled Cys is released from tRNA at a high rate. We discuss possible translation independent functions for tRNACys

Insights from the genome of the biotrophic fungal plant pathogen Ustilago maydis

Ustilago maydis is a ubiquitous pathogen of maize and a well-established model organism for the study of plant-microbe interactions. This basidiomycete fungus does not use aggressive virulence strategies to kill its host. U. maydis belongs to the group of biotrophic parasites (the smuts) that depend on living tissue for proliferation and development. Here we report the genome sequence for a member of this economically important group of biotrophic fungi. The 20.5-million-base U. maydis genome assembly contains 6,902 predicted protein-encoding genes and lacks pathogenicity signatures found in the genomes of aggressive pathogenic fungi, for example a battery of cell-wall-degrading enzymes. However, we detected unexpected genomic features responsible for the pathogenicity of this organism. Specifically, we found 12 clusters of genes encoding small secreted proteins with unknown function. A significant fraction of these genes exists in small gene families. Expression analysis showed that most of the genes contained in these clusters are regulated together and induced in infected tissue. Deletion of individual clusters altered the virulence of U. maydis in five cases, ranging from a complete lack of symptoms to hypervirulence. Despite years of research into the mechanism of pathogenicity in U. maydis, no 'true' virulence factors had been previously identified. Thus, the discovery of the secreted protein gene clusters and the functional demonstration of their decisive role in the infection process illuminate previously unknown mechanisms of pathogenicity operating in biotrophic fungi. Genomic analysis is, similarly, likely to open up new avenues for the discovery of virulence determinants in other pathogens. ©2006 Nature Publishing Group.J.K., M. B. and R.K. thank G. Sawers and U. Kämper for critical reading of the manuscript. The genome sequencing of Ustilago maydis strain 521 is part of the fungal genome initiative and was funded by National Human Genome Research Institute (USA) and BayerCropScience AG (Germany). F.B. was supported by a grant from the National Institutes of Health (USA). J.K. and R.K. thank the German Ministry of Education and Science (BMBF) for financing the DNA array setup and the Max Planck Society for their support of the manual genome annotation. F.B. was supported by a grant from the National Institutes of Health, B.J.S. was supported by the Natural Sciences and Engineering Research Council of Canada and the Canada Foundation for Innovation, J.W.K. received funding from the Natural Sciences and Engineering Research Council of Canada, J.R.-H. received funding from CONACYT, México, A.M.-M. was supported by a fellowship from the Humboldt Foundation, and L.M. was supported by an EU grant. Author Contributions All authors were involved in planning and executing the genome sequencing project. B.W.B., J.G., L.-J.M., E.W.M., D.D., C.M.W., J.B., S.Y., D.B.J., S.C., C.N., E.K., G.F., P.H.S., I.H.-H., M. Vaupel, H.V., T.S., J.M., D.P., C.S., A.G., F.C. and V. Vysotskaia contributed to the three independent sequencing projects; M.M., G.M., U.G., D.H., M.O. and H.-W.M. were responsible for gene model refinement, database design and database maintenance; G.M., J. Kämper, R.K., G.S., M. Feldbrügge, J.S., C.W.B., U.F., M.B., B.S., B.J.S., M.J.C., E.C.H.H., S.M., F.B., J.W.K., K.J.B., J. Klose, S.E.G., S.J.K., M.H.P., H.A.B.W., R.deV., H.J.D., J.R.-H., C.G.R.-P., L.O.-C., M.McC., K.S., J.P.-M., J.I.I., W.H., P.G., P.S.-A., M. Farman, J.E.S., R.S., J.M.G.-P., J.C.K., W.L. and D.H. were involved in functional annotation and interpretation; T.B., O.M., L.M., A.M.-M., D.G., K.M., N.R., V. Vincon, M. VraneŠ, M.S. and O.L. performed experiments. J. Kämper, R.K. and M.B. wrote and edited the paper with input from L.-J.M., J.G., F.B., J.W.K., B.J.S. and S.E.G. Individual contributions of authors can be found as Supplementary Notes

Physiological Correlates of Volunteering

We review research on physiological correlates of volunteering, a neglected but promising research field. Some of these correlates seem to be causal factors influencing volunteering. Volunteers tend to have better physical health, both self-reported and expert-assessed, better mental health, and perform better on cognitive tasks. Research thus far has rarely examined neurological, neurochemical, hormonal, and genetic correlates of volunteering to any significant extent, especially controlling for other factors as potential confounds. Evolutionary theory and behavioral genetic research suggest the importance of such physiological factors in humans. Basically, many aspects of social relationships and social activities have effects on health (e.g., Newman and Roberts 2013; Uchino 2004), as the widely used biopsychosocial (BPS) model suggests (Institute of Medicine 2001). Studies of formal volunteering (FV), charitable giving, and altruistic behavior suggest that physiological characteristics are related to volunteering, including specific genes (such as oxytocin receptor [OXTR] genes, Arginine vasopressin receptor [AVPR] genes, dopamine D4 receptor [DRD4] genes, and 5-HTTLPR). We recommend that future research on physiological factors be extended to non-Western populations, focusing specifically on volunteering, and differentiating between different forms and types of volunteering and civic participation

Chapitre 14: Phytopathogènes et stratégies de contrôle en aquaponie

peer reviewedAmong the diversity of plant diseases occurring in aquaponics, soil-borne pathogens, such as Fusarium spp., Phytophthora spp. and Pythium spp., are the most problematic due to their preference for humid/aquatic environment conditions. Phytophthora spp. and Pythium spp. which belong to the Oomycetes pseudo-fungi require special attention because of their mobile form of dispersion, the so-called zoospores that can move freely and actively in liquid water. In coupled aquaponics, curative methods are still limited because of the possible toxicity of pesticides and chemical agents for fish and beneficial bacteria (e.g. nitrifying bacteria of the biofilter). Furthermore, the development of biocontrol agents for aquaponic use is still at its beginning. Consequently, ways to control the initial infection and the progression of a disease are mainly based on preventive actions and water physical treatments. However, suppressive action (suppression) could happen in aquaponic environment considering recent papers and the suppressive activity already highlighted in hydroponics. In addition, aquaponic water contains organic matter that could promote establishment and growth of heterotrophic bacteria in the system or even improve plant growth and viability directly. With regards to organic hydroponics (i.e. use of organic fertilisation and organic plant media), these bacteria could act as antagonist agents or as plant defence elicitors to protect plants from diseases. In the future, research on the disease suppressive ability of the aquaponic biotope must be increased, as well as isolation, characterisation and formulation of microbial plant pathogen antagonists. Finally, a good knowledge in the rapid identification of pathogens, combined with control methods and diseases monitoring, as recommended in integrated plant pest management, is the key to an efficient control of plant diseases in aquaponics.Cos

Lifelong Learning and ABSEL: An Inquiry Definition and Relationships

Lifelong learning is a major issue in education. But it is rarely defined and much of what is said relate. to the need for it and the way it is fostered through administrative practices. An initial inquiry of ABSEL members showed great interest in lifelong learning and its possible relationships to simulation and experiential learning. Members were surveyed on the definition of lifelong learning as an attitude, activity, or skill. They were asked how simulations and experiential learning could impact on lifelong learning. And they were asked to identify the factors in simulations and experiential learning that might impact favorably on experiential learning

Developing a Recruitment and Selection Strategy a Raise II Exercise

RAISE II, a Personnel Simulation is a simulation designed to present participants with the opportunity to practically apply personnel skills to a job. From the initial analysis of the job and the writing of a job description, the participants continually interact with the job and each other to complete the various parts of a personnel program. This can include any of the various functions of a personnel program, including equal employment, wage determination, training, employee evaluation, interviewing, and/or recruitment and selection

Raise II: First Year Experiences with a Personnel Simulation

"RAISE II, A Personnel Simulation is a simulation designed for use in management, personnel, general business, and small business classes. It was designed from a series of short individual lectures and assignments in personnel. From this series of short individual projects and assignments, and input from students and businessmen, the twelve basic modules of RAISE II were created. RAISE II, an acronym for Recruitment, Analysis, Interview, Selection, and Employee Evaluation, is a personnel simulation in which participants assume the role of Personnel Assistants for a company which specializes in the performance of personnel activities on a consulting basis. The manual explains that the founders of RAISE II have developed expertise in all areas of personnel, enabling them to accept contracts ranging from the performance of a large part of a company’s personnel work, including job analysis, testing, recruitment, interviewing, selection, wage determination, training, and employee evaluation.

Instructor's Manual - RAISE II - A Personnel Simulation

RAISE II, A Personnel Simulation, is a modular simulation designed to provide participants with the practical experience of applying the principles of personnel management. It is a complete package containing instructions and all necessary forms

Measurement of Administrator Role for Feedback on Structure and Goals

In experiential learning materials and simulations, the administrator of the program can be considered to play a role throughout the activity. An examination of previous research and a collection of personal experiences reveal that these roles can be appropriately labeled: the ADMINISTRATOR, the CONSULTANT, the EVALUATOR, the PARTICIPANT, the FACILITATOR, the PRESIDENT, the OBSERVER and the PRESIDENT. In any given experiential exercise or simulation the instructor may play several of these roles, creating a composite with one or more of the roles having a significant impact on the results of the experience. At the 1977 ABSEL meeting, the identification of these roles was proposed and discussed in a lively session on simulations and experiential leaning which featured related presentations by Burns, Gentry and Keys. In that session ABSEL members clearly demonstrated their willingness to encourage new ways of looking at our educational activities and continued to discuss and challenge each others ideas in a free speaking, positive discussion of the different ideas that were presented

The Role of the Administrator in Experiential Learning and Simulations

In experiential learning materials and in simulations, the nature of the materials, the objectives of the administrator, and the personality of all the characters involved force the administrator to play a role throughout the experience. An examination of previous research and a collection of personal experiences reveal that these roles can be appropriately labeled the “ADMINISTRATOR”, the “CONSULTANT”, the “EVALUATOR”, the “PARTICIPANT”, the “FACILITATOR”, the “PRESIDENT”, the “OBSERVER”, and the “PRESENCE”. In any given experiential exercise or simulation, the instructor may play several of these roles, creating a composite role with one or more of the roles having a significant impact on the results of the experience. This, however, is the important point: that the role of the instructor, while originally affected by the simulation or experience and the nature and goals of the material, in turn affects the outcomes