CncRNAs : RNAs with both coding and non-coding roles in development

RNAs are known to regulate diverse biological processes, either as protein-encoding molecules or as non-coding RNAs. However, a third class that comprises RNAs endowed with both protein coding and non-coding functions has recently emerged. Such bi-functional ‘coding and non-coding RNAs’ (cncRNAs) have been shown to play important roles in distinct developmental processes in plants and animals. Here, we discuss key examples of cncRNAs and review their roles, regulation and mechanisms of action during development

Drosophila Ge-1 Promotes P Body Formation and oskar mRNA Localization

mRNA localization coupled with translational control is a widespread and conserved strategy that allows the localized production of proteins within eukaryotic cells. In Drosophila, oskar (osk) mRNA localization and translation at the posterior pole of the oocyte are essential for proper patterning of the embryo. Several P body components are involved in osk mRNA localization and translational repression, suggesting a link between P bodies and osk RNPs. In cultured mammalian cells, Ge-1 protein is required for P body formation. Combining genetic, biochemical and immunohistochemical approaches, we show that, in vivo, Drosophila Ge-1 (dGe-1) is an essential gene encoding a P body component that promotes formation of these structures in the germline. dGe-1 partially colocalizes with osk mRNA and is required for osk RNP integrity. Our analysis reveals that although under normal conditions dGe-1 function is not essential for osk mRNA localization, it becomes critical when other components of the localization machinery, such as staufen, Drosophila decapping protein 1 and barentsz are limiting. Our findings suggest an important role of dGe-1 in optimization of the osk mRNA localization process required for patterning the Drosophila embryo

Ruth Lehmann: Germ cells do things differently

Lehmann studies the developmental program that sets the germ line apart from somatic cells

Life in the shadow: an examination of the minor foreign relations of the DPRK

Reissued 27 Sep 2018 to reflect updated abstract on pages i and v and to correct the spelling of DPRK throughout.This thesis explores the diplomatic relations of North Korea, officially known as the Democratic People's Republic of Korea (DPRK), with an emphasis on its minor diplomatic relations. Minor, for purposes of this thesis, refers to those states other than the Big Four Plus One (i.e., China, Japan, South Korea, Russia, and the United States). This thesis covers the evolution of these relations, assesses trends, and predicts the direction in which these relations may be headed. While many refer to North Korea as a hermit kingdom, its diplomatic relations challenge this label. The DPRK has been and remains active diplomatically. The DRPK enjoys close relations with many states that continue to be marked by the rhetoric of a previous era. There is more continuity than change in its minor foreign relations; however, signs of new life cannot be ignored. While most of its bilateral-minor relations were established to help bolster its claim as the sole legitimate government of the Korean Peninsula, these relationships have become more important as the DPRK has become increasingly isolated. Furthermore, by keeping these relations warm, they assist Pyongyang in its possible efforts to engage in diplomatic hedging if needed. Over the years, as Pyongyang's relationship with its primary benefactors has waxed and waned, it has engaged in expanded diplomatic efforts. In mid-2013, as China supported efforts for a more universal application of further restrictive sanctions on the DPRK, the beginning of a cooling period in DPRK-PRC relations can be seen. Given this potential waning of relations with its sole primary benefactor, the DPRK can be expected to enter into a new period of more energetic diplomacy.http://archive.org/details/lifeinshadownexa1094541372Lieutenant, United States NavyApproved for public release; distribution is unlimited

The Ig cell adhesion molecule Basigin controls compartmentalization and vesicle release at Drosophila melanogaster synapses

Synapses can undergo rapid changes in size as well as in their vesicle release function during both plasticity processes and development. This fundamental property of neuronal cells requires the coordinated rearrangement of synaptic membranes and their associated cytoskeleton, yet remarkably little is known of how this coupling is achieved. In a GFP exon-trap screen, we identified Drosophila melanogaster Basigin (Bsg) as an immunoglobulin domain-containing transmembrane protein accumulating at periactive zones of neuromuscular junctions. Bsg is required pre- and postsynaptically to restrict synaptic bouton size, its juxtamembrane cytoplasmic residues being important for that function. Bsg controls different aspects of synaptic structure, including distribution of synaptic vesicles and organization of the presynaptic cortical actin cytoskeleton. Strikingly, bsg function is also required specifically within the presynaptic terminal to inhibit nonsynchronized evoked vesicle release. We thus propose that Bsg is part of a transsynaptic complex regulating synaptic compartmentalization and strength, and coordinating plasma membrane and cortical organization

The Role of Regulated mRNA Stability in Establishing Bicoid Morphogen Gradient in Drosophila Embryonic Development

The Bicoid morphogen is amongst the earliest triggers of differential spatial pattern of gene expression and subsequent cell fate determination in the embryonic development of Drosophila. This maternally deposited morphogen is thought to diffuse in the embryo, establishing a concentration gradient which is sensed by downstream genes. In most model based analyses of this process, the translation of the bicoid mRNA is thought to take place at a fixed rate from the anterior pole of the embryo and a supply of the resulting protein at a constant rate is assumed. Is this process of morphogen generation a passive one as assumed in the modelling literature so far, or would available data support an alternate hypothesis that the stability of the mRNA is regulated by active processes? We introduce a model in which the stability of the maternal mRNA is regulated by being held constant for a length of time, followed by rapid degradation. With this more realistic model of the source, we have analysed three computational models of spatial morphogen propagation along the anterior-posterior axis: (a) passive diffusion modelled as a deterministic differential equation, (b) diffusion enhanced by a cytoplasmic flow term; and (c) diffusion modelled by stochastic simulation of the corresponding chemical reactions. Parameter estimation on these models by matching to publicly available data on spatio-temporal Bicoid profiles suggests strong support for regulated stability over either a constant supply rate or one where the maternal mRNA is permitted to degrade in a passive manner