Biomedical subjects

E Gonzalez-Couto

Publications and source records attributed to E Gonzalez-Couto.

3 recordsLinked to original sources

PubMed2002

Automated recognition of intracellular organelles in confocal microscope images.

Recognition of the localisation of intracellular proteins is essential to the understanding of their function. It is usually made through knowledge of and comparison to the distribution of well-characterised intracellular organelles by experts in cell biology. We have automated this process in order to achieve a more objective and quantitative assessment of the protein distribution within the cell, which can be employed by the less experienced cell biologist and may be utilised as a training program for inexperienced users, or as a high throughput localisation program for novel genes in functional analysis. Here we describe the development and testing of a classification system based on a modular neural network trained with sets of confocal sections through cell lines fluorescently stained for markers of key intracellular structures. The system functioned well in spite of the variability in pattern that occurs between individual cells and performed with 97% accuracy, which gives us confidence in the method and in its future development. It is envisaged that this program will aid the design of further experiments utilising colocalisation with known organelle marker proteins, in order to confirm putative trafficking pathways and protein--protein interactions of the protein of interest.

Animals↗

PubMed2001

The life sciences Global Image Database (GID).

Although a vast amount of life sciences data is generated in the form of images, most scientists still store images on extremely diverse and often incompatible storage media, without any type of metadata structure, and thus with no standard facility with which to conduct searches or analyses. Here we present a solution to unlock the value of scientific images. The Global Image Database (GID) is a web-based (http://www.gwer.ch/qv/gid/gid.ht m ) structured central repository for scientific annotated images. The GID was designed to manage images from a wide spectrum of imaging domains ranging from microscopy to automated screening. The annotations in the GID define the source experiment of the images by describing who the authors of the experiment are, when the images were created, the biological origin of the experimental sample and how the sample was processed for visualization. A collection of experimental imaging protocols provides details of the sample preparation, and labeling, or visualization procedures. In addition, the entries in the GID reference these imaging protocols with the probe sequences or antibody names used in labeling experiments. The GID annotations are searchable by field or globally. The query results are first shown as image thumbnail previews, enabling quick browsing prior to original-sized annotated image retrieval. The development of the GID continues, aiming at facilitating the management and exchange of image data in the scientific community, and at creating new query tools for mining image data.

Biological Science Disciplines↗

PubMed1997

Synergistic and promoter-selective activation of transcription by recruitment of transcription factors TFIID and TFIIB.

Eukaryotic transcriptional activators may function by stimulating formation of RNA polymerase II preinitiation complexes at the core promoter of genes. In this case, their mode of action will intrinsically depend on how these complexes assemble on promoters in living cells, an issue that remains largely unexplored. Here we show that in yeast the basal transcription machinery is brought to the promoter in the form of at least two subcomplexes, TFIID and a complex comprising TFIIB and other essential components. Individual recruitment of either complex by artificial contact with a transcriptionally inactive, sequence-specific DNA-binding protein suffices to trigger transcriptional activation from a wild-type core promoter bearing the appropriate binding site. In contrast, activation from a promoter containing a weakened TATA element is only observed upon recruitment of TFIID. Tethering TFIIB on that promoter remains without effect, but the simultaneous recruitment of both components leads to strong synergistic activation. These findings suggest a simple mechanism whereby two activators that contact distinct subcomplexes of the basal machinery may stimulate transcription synergistically and differentially depending on the nature of the promoter.

Promoter Regions, Genetic↗