ELAV mediates 3' UTR extension in the Drosophila nervous system

Post-transcriptional gene regulation is prevalent in the nervous system, where multiple tiers of regulatory complexity contributeto the development and function of highly specialized cell types. Whole-genome studies in Drosophila have identified several hundred genes containing long 3′ extensions in neural tissues. We show that ELAV (embryonic-lethalabnormal visual system) is a key mediator of these neural-specific extensions. Misexpression of ELAV results in the ectopicsynthesis of long messenger RNAs (mRNAs) in transgenic embryos. RNA immunoprecipitation assays suggest that ELAV directlybinds the proximal polyadenylation signals of many target mRNAs. Finally, ELAV is sufficient to suppress 3′ end formationat a strong polyadenylation signal when tethered to a synthetic RNA. We propose that this mechanism for coordinating 3′ UTRextension may be generally used in a variety of cellular processes

Using Children\u27s Literature to Enrich the Social Studies Program in a Fifth Grade Study of the United States

Children\u27s literature can enliven and enrich a social studies program. The role of children\u27s literature in content subjects, especially social studies on the elementary level was studied. The types of children\u27s literature which can be used in social studies, namely informational books, biographies, historical fiction, were also studied. In addition bibliographies were consulted for repeated mention of the best selections. Based upon the findings cited above a selected annotated bibliography of selections of poetry and children\u27s books was produced for use in a fifth grade study of the United States

Emergent modular neural control drives coordinated motor actions.

A remarkable feature of motor control is the ability to coordinate movements across distinct body parts into a consistent, skilled action. To reach and grasp an object, 'gross' arm and 'fine' dexterous movements must be coordinated as a single action. How the nervous system achieves this coordination is currently unknown. One possibility is that, with training, gross and fine movements are co-optimized to produce a coordinated action; alternatively, gross and fine movements may be modularly refined to function together. To address this question, we recorded neural activity in the primary motor cortex and dorsolateral striatum during reach-to-grasp skill learning in rats. During learning, the refinement of fine and gross movements was behaviorally and neurally dissociable. Furthermore, inactivation of the primary motor cortex and dorsolateral striatum had distinct effects on skilled fine and gross movements. Our results indicate that skilled movement coordination is achieved through emergent modular neural control

The European Large Area ISO Survey - ISOPHOT results using the MPIA-pipeline

The European Large Area ISO Survey (ELAIS) will provide Infrared observations of 4 regions in the sky with ISO. Around 2000 Infrared sources have been detected at 7 and 15 microns (with ISOCAM), 90 and 175 microns (with ISOPHOT)) over 13 square degrees of the sky. We present the source extraction pipeline of the 90 microns ISOPHOT observations, describe and discuss the results obtained and derive the limits of the ELAIS observational strategy.Comment: 4 pages, 5 figures, to appear in the ISO conference "The Universe as seen by ISO", 1998, UNESCO, Pari

ELAV links paused Pol II to alternative polyadenylation in the Drosophila nervious system

Alternative polyadenylation (APA) has been implicated in a variety of developmental and disease processes. A particularly dramatic form of APA occurs in the developing nervous system of flies and mammals, whereby various developmental genes undergo coordinate 3' UTR extension. In Drosophila, the RNA-binding protein ELAV inhibits RNA processing at proximal polyadenylation sites, thereby fostering the formation of exceptionally long 3' UTRs. Here, we present evidence that paused Pol II promotes recruitment of ELAV to extended genes. Replacing promoters of extended genes with heterologous promoters blocks normal 3' extension in the nervous system, while extension-associated promoters can induce 3' extension in ectopic tissues expressing ELAV. Computational analyses suggest that promoter regions of extended genes tend to contain paused Pol II and associated cis-regulatory elements such as GAGA. ChIP-seq assays identify ELAV in the promoter regions of extended genes. Our study provides evidence for a regulatory link between promoter-proximal pausing and APA

Quasispecies evolution in general mean-field landscapes

I consider a class of fitness landscapes, in which the fitness is a function of a finite number of phenotypic "traits", which are themselves linear functions of the genotype. I show that the stationary trait distribution in such a landscape can be explicitly evaluated in a suitably defined "thermodynamic limit", which is a combination of infinite-genome and strong selection limits. These considerations can be applied in particular to identify relevant features of the evolution of promoter binding sites, in spite of the shortness of the corresponding sequences.Comment: 6 pages, 2 figures, Europhysics Letters style (included) Finite-size scaling analysis sketched. To appear in Europhysics Letter

People-Environment Trade-offs in Managing Communal Rangelands of South Africa

Communal rangelands in South Africa support a range of ecosystem services including water provision, carbon sequestration and livestock production for different stakeholders. Delivering these in a sustainable and socially appropriate manner necessarily requires trade-offs to be made between the different environmental and social outcomes required. We draw on empirical fieldwork and a two-day participatory stakeholder workshop to report on the early stages of a project evaluating these trade-offs in communal rangelands of the uMzimvubu catchment in Eastern Cape Province. Our findings suggest that trade-offs will be necessary at a variety of different levels within this system. For example, a key activity within these rangelands is removal of invasive plants such as wattle (Acacia mearnsii) but the environmental gains are conflictual as although this increases water availability within the system, it potentially reduces stored carbon. Wattle removal also highlights a disconnection between people and policy. While current policy mandates complete eradication of wattle, none of the local communities involved in the research wished to see this, as most of them currently make use of the trees for a range of purposes including timber, fuelwood and even livestock feed. Furthermore, trade-offs are also required between different community members, in terms of the social outcomes rangelands can deliver for them. While men conceptualised rangelands largely in terms of maximising livestock production, women focused on the collection of natural resources such as timber, herbs and thatching grass, the latter requiring accumulation of biomass during the growing season and potentially removing areas of rangeland from grazing. Understanding the opposing goals for rangeland use that exist within and between different stakeholder groups is critical to evaluating the social and environmental trade-offs required and to reach a consensus approach to the governance and management of these systems