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Adv Exp Med Biol,
2011]
During the last decade of the 20th century a totally novel way of gene regulation was revealed. Findings that at frst glance appeared freak features of plants or C. elegans turned out to be mechanistically related and deeply conserved throughout evolution. this important insight was primed by the landmark discovery of RNA interference, or RNAi, in 1998. This work started an entire novel feld of research, now usually referred to as RNA silencing. the common denominator of the phenomena grouped in this feld are small RNA molecules, often derived from double stranded RNA precursors, that in association with proteins of the so-called Argonaute family, are capable of directing a variety of effector complexes to cognate RNA and/or DNA molecules. one of these processes is now widely known as microRNA-mediated gene silencing and I will provide a partially historical framework of the many steps that have led to our current understanding of micro RNA biogenesis and function. this chapter is meant to provide a general overview of the various processes involved. for a comprehensive description of current models, I refer interested readers to the reviews and primary literature references provided in this chapter and to the further contents of this book.
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Adv Exp Med Biol,
2010]
During the last decade of the 20th century a totally novel way of gene regulation was revealed. Findings that at first glance appeared freak features of plants or C. elegans turned out to be mechanistically related and deeply conserved throughout evolution. This important insight was primed by the landmark discovery of RNA interference, or RNAi, in 1998. This work started an entire novel field of research, now usually referred to as RNA silencing. The common denominator of the phenomena grouped in this field are small RNA molecules, often derived from double stranded RNA precursors, that in association with proteins of the so-called Argonaute family, are capable of directing a variety of effector complexes to cognate RNA and/or DNA molecules. One of these processes is now widely known as microRNA-mediated gene silencing and I will provide a partially historical framework of the many steps that have led to our current understanding of microRNA biogenesis and function. This chapter is meant to provide a general overview of the various processes involved. For a comprehensive description of current models, I refer interested readers to the reviews and primary literature references provided in this chapter and to the further contents of this book.
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J R Soc Interface,
2017]
Network neuroscience is the emerging discipline concerned with investigating the complex patterns of interconnections found in neural systems, and identifying principles with which to understand them. Within this discipline, one particularly powerful approach is network generative modelling, in which wiring rules are algorithmically implemented to produce synthetic network architectures with the same properties as observed in empirical network data. Successful models can highlight the principles by which a network is organized and potentially uncover the mechanisms by which it grows and develops. Here, we review the prospects and promise of generative models for network neuroscience. We begin with a primer on network generative models, with a discussion of compressibility and predictability, and utility in intuiting mechanisms, followed by a short history on their use in network science, broadly. We then discuss generative models in practice and application, paying particular attention to the critical need for cross-validation. Next, we review generative models of biological neural networks, both at the cellular and large-scale level, and across a variety of species including Caenorhabditis elegans, Drosophila, mouse, rat, cat, macaque and human. We offer a careful treatment of a few relevant distinctions, including differences between generative models and null models, sufficiency and redundancy, inferring and claiming mechanism, and functional and structural connectivity. We close with a discussion of future directions, outlining exciting frontiers both in empirical data collection efforts as well as in method and theory development that, together, further the utility of the generative network modelling approach for network neuroscience.
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Front Cell Neurosci,
2014]
Glial cells of Caenorhabditis elegans can modulate neuronal activity and behavior, which is the focus of this review. Initially, we provide an overview of neuroglial evolution, making a comparison between C. elegans glia and their genealogical counterparts. What follows is a brief discussion on C. elegans glia characteristics in terms of their exact numbers, germ layers origin, their necessity for proper development of sensory organs, and lack of their need for neuronal survival. The more specific roles that various glial cells have on neuron-based activity/behavior are succinctly presented. The cephalic sheath glia are important for development, maintenance and activity of central synapses, whereas the amphid glia seem to set the tone of sensory synapses; these glial cell types are ectoderm-derived. Mesoderm-derived Glial-Like cells in the nerve Ring (GLRs) appear to be a part of the circuit for production of motor movement of the worm anterior. Finally, we discuss tools and approaches utilized in studying C. elegans glia, which are assets available for this animal, making it an appealing model, not only in neurosciences, but in biology in general.
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FEBS Lett,
2010]
DNA double strand breaks and blocked or collapsed DNA replication forks are potentially genotoxic lesions that can result in deletions, aneuploidy or cell death. Homologous recombination (HR) is an essential process employed during repair of these forms of damage. HR allows for accurate restoration of the damaged DNA through use of a homologous template for repair. Although inroads have been made towards understanding the mechanisms of HR, ambiguity still surrounds aspects of the process. Until recently, relatively little was known concerning metabolism of postsynaptic RAD51 filaments or how synthesis dependent strand annealing intermediates are processed. This review discusses recent findings implicating RTEL1, HELQ and the Caenorhabditis elegans RAD51 paralog RFS-1 in post-strand exchange events during HR.