11 research outputs found

    Bee phylogeny data

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    A combined file including an alignment of LW-rhodopsin of bees and an xml file which was used as input file for BEAST analyse

    Data from: Tracing horizontal Wolbachia movements among bees (Anthophila): a combined approach using multilocus sequence typing data and host phylogeny

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    The endosymbiotic bacterium Wolbachia enhances its spread via vertical transmission by generating reproductive effects in its hosts, most notably cytoplasmic incompatibility (CI). Additionally, frequent interspecific horizontal transfer is evident from a lack of phylogenetic congruence between Wolbachia and its hosts. The mechanisms of this lateral transfer are largely unclear. To identify potential pathways of Wolbachia movements, we performed multilocus sequence typing of Wolbachia strains from bees (Anthophila). Using a host phylogeny and ecological data, we tested various models of horizontal endosymbiont transmission. In general, Wolbachia strains seem to be randomly distributed among bee hosts. Kleptoparasite-host associations among bees as well as other ecological links could not be supported as sole basis for the spread of Wolbachia. However, cophylogenetic analyses and divergence time estimations suggest that Wolbachia may persist within a host lineage over considerable timescales and that strictly vertical transmission and subsequent random loss of infections across lineages may have had a greater impact on Wolbachia strain distribution than previously estimated. Although general conclusions about Wolbachia movements among arthropod hosts cannot be made, we present a framework by which precise assumptions about shared evolutionary histories of Wolbachia and a host taxon can be modelled and tested

    Wolbachia MLST alignments

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    A combined file containing MLST alignments of large and small Wolbachia dataset, both in ClonalFrame input file format. Also, a Nexus file of 100 best trees of Wolbachia strains from bee hosts, as inferred with MrBayes. These trees were used asinput in BayesTraits analyse

    Obtaining a Proportional Allocation by Deleting Items

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    We consider the following control problem on fair allocation of indivisible goods. Given a set I of items and a set of agents, each having strict linear preference over the items, we ask for a minimum subset of the items whose deletion guarantees the existence of a proportional allocation in the remaining instance; we call this problem Proportionality by Item Deletion (PID). Our main result is a polynomial-time algorithm that solves PID for three agents. By contrast, we prove that PID is computationally intractable when the number of agents is unbounded, even if the number k of item deletions allowed is small, since the problem turns out to be W[3]-hard with respect to the parameter k. Additionally, we provide some tight lower and upper bounds on the complexity of PID when regarded as a function of |I| and k

    Involvement of the Adhesion GPCRs Latrophilins in the Regulation of Insulin Release

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    Summary: Insulin secretion from pancreatic β cells is a highly complex and tightly regulated process. Its dysregulation is one characteristic of type 2 diabetes, and thus, an in-depth understanding of the mechanisms controlling insulin secretion is essential for rational therapeutic intervention. G-protein-coupled receptors (GPCRs) have been established as major regulators of insulin exocytosis. Recent studies also suggest the involvement of adhesion GPCRs, a non-prototypical class of GPCRs. Here, we identify latrophilins, which belong to the class of adhesion GPCRs, to be highly expressed in different cell types of pancreatic islets. In vitro and ex vivo analyses show that distinct splice variants of the latrophilin LPHN3/ADGRL3 decrease insulin secretion from pancreatic β cells by reducing intracellular cyclic AMP levels via the Gi-mediated pathway. Our data highlight the key role of LPHN3 in modulating insulin secretion and its potential as therapeutic target for type 2 diabetes. : With diabetes becoming an epidemic disease, understanding processes regulating insulin secretion is a major task. Röthe et al. show that tissue-specific splice variants of the adhesion GPCR Latrophilin-3 in pancreatic islets modulate insulin secretion. In contrast to other variants, they reduce intracellular cAMP via a Gi protein pathway. Keywords: adhesion GPCRs, latrophilins, insulin secretion, signaling, splice variant

    The therapeutic potential of GLP-1 receptor biased agonism

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    Glucagon-like peptide-1 (GLP-1) receptor agonists are effective treatments for type 2 diabetes as they stimulate insulin release and promote weight loss through appetite suppression. Their main side effect is nausea. All approved GLP-1 agonists are full agonists across multiple signalling pathways. However, selective engagement with specific intracellular effectors, or biased agonism, has been touted as a means to improve GLP-1 agonists therapeutic efficacy. In this review, I critically examine how GLP-1 receptor-mediated intracellular signalling is linked to physiological responses and discuss the implications of recent studies investigating the metabolic effects of biased GLP-1 agonists. Overall, there is little conclusive evidence that beneficial and adverse effects of GLP-1 agonists are attributable to distinct, nonoverlapping signalling pathways. Instead, G protein-biased GLP-1 agonists appear to achieve enhanced anti-hyperglycaemic efficacy by avoiding GLP-1 receptor desensitisation and downregulation, partly via reduced β-arrestin recruitment. This effect seemingly applies more to insulin release than to appetite regulation and nausea, possible reasons for which are discussed. At present, most evidence derives from cellular and animal studies, and more human data are required to determine whether this approach represents a genuine therapeutic advance
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