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A critical mediator of cell-cell signaling events during embryogenesis is the highly conserved Wnt family of secreted proteins. Reporter constructs containing multimerized TCF DNA binding sites have been used to detect Wnt β-catenin dependent activity during animal development. In this report, we have constructed and compared several TCF green fluorescent protein (GFP) reporter constructs. They contained 3, 8, or 12 TCF binding sites upstream of a minimal promoter driving native or destabilized enhanced GFP (EGFP). We have used the electroporation of somites in the chick embryo as a paradigm to test them in vivo. We have verified that they all respond to Wnt signaling in vivo. We have then assessed their efficiency at reflecting the activity of the Wnt pathway. Using destabilized EGFP reporter constructs, we show that somite cells dynamically regulate Wnt/β-catenin-dependent signaling, a finding that was confirmed by performing time-lapse video confocal observation of electroporated embryos. Developmental Dynamics 239:346-353, 2010. © 2009 Wiley-Liss, Inc. [ABSTRACT FROM AUTHOR]

There is an increasing interest in developing ontologies and controlled vocabularies to improve the efficiency and consistency of manual literature curation, to enable more formal biocuration workflow results and ultimately to improve analysis of biological data. Two ontologies that have been successfully used for this purpose are the Gene Ontology (GO) for annotating aspects of gene products and the Molecular Interaction ontology (PSI-MI) used by databases that archive protein–protein interactions. The examination of protein interactions has proven to be extremely promising for the understanding of cellular processes. Manual mapping of information from the biomedical literature to bio-ontology terms is one of the most challenging components in the curation pipeline. It requires that expert curators interpret the natural language descriptions contained in articles and infer their semantic equivalents in the ontology (controlled vocabulary). Since manual curation is a time-consuming process, there is strong motivation to implement text-mining techniques to automatically extract annotations from free text. A range of text mining strategies has been devised to assist in the automated extraction of biological data. These strategies either recognize technical terms used recurrently in the literature and propose them as candidates for inclusion in ontologies, or retrieve passages that serve as evidential support for annotating an ontology term, e.g. from the PSI-MI or GO controlled vocabularies. Here, we provide a general overview of current text-mining methods to automatically extract annotations of GO and PSI-MI ontology terms in the context of the BioCreative (Critical Assessment of Information Extraction Systems in Biology) challenge. Special emphasis is given to protein–protein interaction data and PSI-MI terms referring to interaction detection methods. [ABSTRACT FROM AUTHOR]

Planar cell polarity (PCP) is the coordinate organization of cells within the plane of a tissue. PCP is essential for tissue function, such as for proper hearing in the vertebrate ear or for accurate vision in the Drosophila eye. Using the chick embryo, we have recently shown that during early muscle formation, the first formed muscle fibres utilize the PCP pathway to orient parallel to a WNT11 source present in the medial border of somites. Our results further establish that WNT11 acts as a directional cue to regulate this process. To perform this study, two major techniques have been utilized, the gene loss-of-function using a vector-based shRNAmir expression and confocal videomicroscopy of fluorescent gene reporters targeted in specific cell subpopulations by in vivo electroporation. Here we describe the two techniques.

A critical mediator of cell-cell signaling events during embryogenesis is the highly conserved Wnt family of secreted proteins. Reporter constructs containing multimerized TCF DNA binding sites have been used to detect Wnt beta-catenin dependent activity during animal development. In this report, we have constructed and compared several TCF green fluorescent protein (GFP) reporter constructs. They contained 3, 8, or 12 TCF binding sites upstream of a minimal promoter driving native or destabilized enhanced GFP (EGFP). We have used the electroporation of somites in the chick embryo as a paradigm to test them in vivo. We have verified that they all respond to Wnt signaling in vivo. We have then assessed their efficiency at reflecting the activity of the Wnt pathway. Using destabilized EGFP reporter constructs, we show that somite cells dynamically regulate Wnt/beta-catenin-dependent signaling, a finding that was confirmed by performing time-lapse video confocal observation of electroporated embryos., ((c) 2009 Wiley-Liss, Inc.)