Cup-ling oskar RNA localization and translational control

RNA localization and spatially restricted translational control can serve to deploy specific proteins to particular places within a cell. oskar (osk) RNA is a key initiatior of posterior patterning and germ cell specification in Drosophila, and its localization and translation are under elaborate control. In this issue, Wilhelm et al. (2003) show that the protein Cup both promotes osk localization and participates in repressing translation of unlocalized osk

Breaking the A chain: regulating mRNAs in development through CCR4 deadenylase

Post-transcriptional mechanisms of gene regulation have long been implicated in specifying embryonic pattern in many organisms. Experiments in Caenorhabditis elegans, Drosophila, and Xenopus have recently converged, pointing to the CCR4 deadenylase complex as a key effector that modulates the expression of proteins from specific germline mRNAs

RanBPM regulates cell shape, arrangement, and capacity of the female germline stem cell niche in Drosophila melanogaster

Experiments in cultured cells with Ran-binding protein M (RanBPM) suggest that it links cell surface receptors and cell adhesion proteins. In this study, we undertake a genetic study of RanBPM function in the germline stem cell (GSC) niche of Drosophila melanogaster ovaries. We find that two RanBPM isoforms are produced from alternatively spliced transcripts, the longer of which is specifically enriched in the GSC niche, a cluster of somatic cells that physically anchors GSCs and expresses signals that maintain GSC fate. Loss of the long isoform from the niche causes defects in niche organization and cell size and increases the number of GSCs attached to the niche. In genetic mosaics for a null RanBPM allele, we find a strong bias for GSC attachment to mutant cap cells and observe abnormal accumulation of the adherens junction component Armadillo (β-catenin) and the membrane skeletal protein Hu-li tai shao in mutant terminal filament cells. These results implicate RanBPM in the regulation of niche capacity and adhesion

Reduced cul-5 Activity Causes Aberrant Follicular Morphogenesis and Germ Cell Loss in Drosophila Oogenesis

Drosophila oogenesis is especially well suited for studying stem cell biology, cellular differentiation, and morphogenesis. The small modifier protein ubiquitin regulates many cellular pathways. Ubiquitin is conjugated to target proteins by a diverse class of enzymes called ubiquitin E3 ligases. Here we characterize the requirement of Cul-5, a key component of a subgroup of Cullin-RING-type ubiquitin E3 ligases, in Drosophila oogenesis. We find that reduced cul-5 activity causes the formation of aberrant follicles that are characterized by excess germ cells. We show that germ line cells overproliferate in cul-5 mutant females, causing the formation of abnormally large germ line cysts. Also, the follicular epithelium that normally encapsulates single germ line cysts develops aberrantly in cul-5 mutant, leading to defects in cyst formation. We additionally found that Cul-5 is required for germ cell maintenance, as germ cells are depleted in a substantial fraction of cul-5 mutant ovaries. All of these cul-5 phenotypes are strongly enhanced by reduced activity of gustavus (gus), which encodes a substrate receptor of Cul-5-based ubiquitin E3 ligases. Taken together, our results implicate Cul-5/Gus ubiquitin E3 ligases in ovarian tissue morphogenesis, germ cell proliferation and maintenance of the ovarian germ cell population

The Distribution of eIF4E-Family Members across Insecta

Insects are part of the earliest faunas that invaded terrestrial environments and are the first organisms that evolved controlled flight. Nowadays, insects are the most diverse animal group on the planet and comprise the majority of extant animal species described. Moreover, they have a huge impact in the biosphere as well as in all aspects of human life and economy; therefore understanding all aspects of insect biology is of great importance. In insects, as in all cells, translation is a fundamental process for gene expression. However, translation in insects has been mostly studied only in the model organism Drosophila melanogaster. We used all publicly available genomic sequences to investigate in insects the distribution of the genes encoding the cap-binding protein eIF4E, a protein that plays a crucial role in eukaryotic translation. We found that there is a diversity of multiple ortholog genes encoding eIF4E isoforms within the genus Drosophila. In striking contrast, insects outside this genus contain only a single eIF4E gene, related to D. melanogaster eIF4E-1. We also found that all insect species here analyzed contain only one Class II gene, termed 4E-HP. We discuss the possible evolutionary causes originating the multiplicity of eIF4E genes within the genus Drosophila

Model matchmaking via the Solve-RD Rare Disease Models & Mechanisms Network (RDMM-Europe)

In biomedical research, particularly for rare diseases (RDs), there is a critical need for model organisms to unravel the mechanistic basis of diseases, perform biomarker studies and develop potential therapeutic interventions. Within Solve-RD, an EU-funded research project with the aim of solving large numbers of previously unsolved RDs, the European Rare Disease Models &amp; Mechanisms Network (RDMM-Europe) has been established.</p

Prediction of Preterm Deliveries from EHG Signals Using Machine Learning

There has been some improvement in the treatment of preterm infants, which has helped to increase their chance of survival. However, the rate of premature births is still globally increasing. As a result, this group of infants are most at risk of developing severe medical conditions that can affect the respiratory, gastrointestinal, immune, central nervous, auditory and visual systems. In extreme cases, this can also lead to long-term conditions, such as cerebral palsy, mental retardation, learning difficulties, including poor health and growth. In the US alone, the societal and economic cost of preterm births, in 2005, was estimated to be $26.2 billion, per annum. In the UK, this value was close to £2.95 billion, in 2009. Many believe that a better understanding of why preterm births occur, and a strategic focus on prevention, will help to improve the health of children and reduce healthcare costs. At present, most methods of preterm birth prediction are subjective. However, a strong body of evidence suggests the analysis of uterine electrical signals (Electrohysterography), could provide a viable way of diagnosing true labour and predict preterm deliveries. Most Electrohysterography studies focus on true labour detection during the final seven days, before labour. The challenge is to utilise Electrohysterography techniques to predict preterm delivery earlier in the pregnancy. This paper explores this idea further and presents a supervised machine learning approach that classifies term and preterm records, using an open source dataset containing 300 records (38 preterm and 262 term). The synthetic minority oversampling technique is used to oversample the minority preterm class, and cross validation techniques, are used to evaluate the dataset against other similar studies. Our approach shows an improvement on existing studies with 96% sensitivity, 90% specificity, and a 95% area under the curve value with 8% global error using the polynomial classifier

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