Liver X Receptors Enhance Epithelial to Mesenchymal Transition in Metastatic Prostate Cancer Cells.

Prostate cancer (PCa) is one of the most common cancers in men. Metastasis is the leading cause of death in prostate cancer patients. One of the crucial processes involved in metastatic spread is the "epithelial-mesenchymal transition" (EMT), which allows cells to acquire the ability to invade distant organs.

Basement membrane diversification relies on two competitive secretory routes defined by Rab10 and Rab8 and modulated by dystrophin and the exocyst complex.

The basement membrane (BM) is an essential structural element of tissues, and its diversification participates in organ morphogenesis. However, the traffic routes associated with BM formation and the mechanistic modulations explaining its diversification are still poorly understood. Drosophila melanogaster follicular epithelium relies on a BM composed of oriented BM fibrils and a more homogenous matrix.

A new bio imagery user-friendly tool for automatic morphometry measurement on muscle cell cultures and histological sections.

TRUEFAD (TRUE Fiber Atrophy Distinction) is a bioimagery user-friendly tool developed to allow consistent and automatic measurement of myotube diameter in vitro, muscle fiber size and type using rodents and human muscle biopsies. This TRUEFAD package was set up to standardize and dynamize muscle research via easy-to-obtain images run on an open-source plugin for FIJI. We showed here both the robustness and the performance of our pipelines to correctly segment muscle cells and fibers.

Easing batch image processing from OMERO: a new toolbox for ImageJ.

The Open Microscopy Environment Remote Objects (OMERO) is an open-source image manager used by many biologists to store, organize, view, and share microscopy images, while the open-source software ImageJ/Fiji is a very popular program used to analyse them. However, there is a lack of an easy-to-use generic tool to run a workflow on a batch of images without having to download them to local computers, and to automatically organize the results in OMERO. To offer this functionality, we have built (i) a library in Java: "Simple OMERO Client", to communicate with an OMERO database from Java software, (ii) an ImageJ/Fiji plugin to run a macro-program on a batch of images from OMERO and (iii) a new set of Macro Functions, "OMERO Macro extensions", dedicated to interact with OMERO in macro-programming.

NANOG initiates epiblast fate through the coordination of pluripotency genes expression.

The epiblast is the source of all mammalian embryonic tissues and of pluripotent embryonic stem cells. It differentiates alongside the primitive endoderm in a "salt and pepper" pattern from inner cell mass (ICM) progenitors during the preimplantation stages through the activity of NANOG, GATA6 and the FGF pathway. When and how epiblast lineage specification is initiated is still unclear.

Oriented basement membrane fibrils provide a memory for F-actin planar polarization via the Dystrophin-Dystroglycan complex during tissue elongation.

How extracellular matrix contributes to tissue morphogenesis is still an open question. In the ovarian follicle, it has been proposed that after Fat2-dependent planar polarization of the follicle cell basal domain, oriented basement membrane (BM) fibrils and F-actin stress fibers constrain follicle growth, promoting its axial elongation. However, the relationship between BM fibrils and stress fibers and their respective impact on elongation are unclear.

Regulation of the ERK signalling pathway in the developing mouse blastocyst.

Activation of the ERK signalling pathway is essential for the differentiation of the inner cell mass (ICM) during mouse preimplantation development. We show here that ERK phosphorylation occurs in ICM precursor cells, in differentiated primitive endoderm (PrE) cells as well as in the mature, formative state epiblast (Epi). We further show that DUSP4 and ETV5, factors often involved in negative-feedback loops of the FGF pathway, are differently regulated.

The interplay between the Argonaute proteins Piwi and Aub within Drosophila germarium is critical for oogenesis, piRNA biogenesis and TE silencing.

Transposable elements (TEs) have invaded most genomes and constitute up to 50% of the human genome. Machinery based on small non-coding piRNAs has evolved to inhibit their expression at the transcriptional and post-transcriptional levels. Surprisingly, this machinery is weakened during specific windows of time in mice, flies or plants, allowing the expression of TEs in germline cells.

sRNAPipe: a Galaxy-based pipeline for bioinformatic in-depth exploration of small RNAseq data.

Background: The field of small RNA is one of the most investigated research areas since they were shown to regulate transposable elements and gene expression and play essential roles in fundamental biological processes. Small RNA deep sequencing (sRNA-seq) is now routinely used for large-scale analyses of small RNA. Such high-throughput sequencing typically produces several millions reads.

Jak-Stat pathway induces follicle elongation by a gradient of apical contractility.

Tissue elongation and its control by spatiotemporal signals is a major developmental question. Currently, it is thought that ovarian follicular epithelium elongation requires the planar polarization of the basal domain cytoskeleton and of the extra-cellular matrix, associated with a dynamic process of rotation around the anteroposterior axis. Here we show, by careful kinetic analysis of mutants, that neither basal planar polarization nor rotation is required during a first phase of follicle elongation.

Tight coordination of growth and differentiation between germline and soma provides robustness for drosophila egg development.

Organs often need to coordinate the growth of distinct tissues during their development. Here, we analyzed the coordination between germline cysts and the surrounding follicular epithelium during Drosophila oogenesis. Genetic manipulations of the growth rate of both germline and somatic cells influence the growth of the other tissue accordingly.

Spatio-temporal requirements for transposable element piRNA-mediated silencing during Drosophila oogenesis.

During Drosophila oogenesis, transposable element (TE) repression involves the Piwi-interacting RNA (piRNA) pathway which ensures genome integrity for the next generation. We developed a transgenic model to study repression of the Idefix retrotransposon in the germline. Using a candidate gene KD-approach, we identified differences in the spatio-temporal requirements of the piRNA pathway components for piRNA-mediated silencing.

NucBase, an easy to use read mapper for small RNAs.

Background: High-throughput deep-sequencing technology has generated an unprecedented number of expressed sequence reads that offer the opportunity to get insight into biological systems. Several databases report the sequence of small regulatory RNAs which play a prominent role in the control of transposable elements (TE). However, the huge amount of data reported in these databases remains mostly unexplored because the available tools are hard for biologists to use.

A role for mesenchyme dynamics in mouse lung branching morphogenesis.

Mammalian airways are highly ramified tree-like structures that develop by the repetitive branching of the lung epithelium into the surrounding mesenchyme through reciprocal interactions. Based on a morphometric analysis of the epithelial tree, it has been recently proposed that the complete branching scheme is specified early in each lineage by a programme using elementary patterning routines at specific sites and times in the developing lung. However, the coupled dynamics of both the epithelium and mesenchyme have been overlooked in this process.

Primitive endoderm differentiates via a three-step mechanism involving Nanog and RTK signaling.

During preimplantation mouse development, the inner cell mass (ICM) differentiates into two cell lineages--the epiblast and the primitive endoderm (PrE)--whose precursors are identifiable by reciprocal expression of Nanog and Gata6, respectively. PrE formation depends on Nanog by a non-cell-autonomous mechanism. To decipher early cell- and non-cell-autonomous effects, we performed a mosaic knockdown of Nanog and found that this is sufficient to induce a PrE fate cell autonomously.