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Biology subjects

Ruel, L.

Publications and source records attributed to Ruel, L..

3 recordsLinked to original sources

Semi supervised GAN for smart microscopy, fast and data efficient cell cycle classification

Modern optical microscopes are fully motorised; however, transforming them into truly smart systems requires real-time adjustment of acquisition settings in response to detected objects and dynamic biological events. At the core are classification algorithms that commonly depend on customised softwares and are generally designed for narrowly-defined biological applications. In addition, they often require substantial annotated datasets for effective training. We introduce a semi-supervised generative adversarial network (SGAN) for robust cell-cycle stage classification under low-resource conditions, adaptable to diverse cellular structures. The framework combines unlabelled microscopy images with synthetically generated samples to mitigate limited annotation, while preserving stable performance even when the unlabelled subset is class-imbalanced. Tested on the Mitocheck dataset, which features five mitosis classes, the model achieved 93{+/-}2% accuracy using only 80 labelled per class and 600 unlabelled images. The proposed algorithm is generic and can be readily adapted to new labeling schemes, classification targets, cell lines, or microscopy modalities through transfer learning. SGAN is well suited for integration into automated microscopes, enabling efficient and adaptable image analysis across diverse biological and microscopy applications.

bioinformatics↗

The Roboscope: Smart and Fast Microscopy for Generic Event-Driven Acquisition

Automation of fluorescence microscopy is a challenge for capturing rare or transient events in biology and medicine. It relies on smart devices that integrate and interpret the observed data, and react to the targeted biological event. We report on the Roboscope, a novel autonomous microscope combining sequence interruption and deep learning integration, allowing generic event-driven acquisitions. This system distinguishes itself by its adaptability to various experiments, quick capture of dynamic events, and minimal data greediness - training with less than 100 images per class. The Roboscopes capability is demonstrated in non-synchronized cells by capturing the metaphase, a 20-minute event happening once per day or less. Conversely, double thymidine-block synchronisation, despite occurring during DNA replication, may perturb mitotic-spindle mechanics. The Roboscopes versatility and efficiency offer significant advancements to tackle the current challenges of cell biology, spreading out advanced microscopy methods to fundamental research as well as high content screening and precision medicine.

bioengineering↗

Microvilli-derived Extracellular Vesicles Govern Morphogenesis in Drosophila wing epithelium

The regulation and coordination of developmental processes involves the secretion of morphogens and membrane carriers, including extracellular vesicles, which facilitate their transport over long distance. The long-range activity of the Hedgehog morphogen is conveyed by extracellular vesicles. However, the site and the molecular basis of their biogenesis remains unknown. By combining fluorescence and electron microscopy combined with genetics and cell biology approaches, we investigated the origin and the cellular mechanisms underlying extracellular vesicle biogenesis, and their contribution to Drosophila wing disc development, exploiting Hedgehog as a long-range morphogen. We show that microvilli of Drosophila wing disc epithelium are the site of generation of small extracellular vesicles that transport Hedgehog across the tissue. This process requires the Prominin-like protein, whose activity, together with interacting cytoskeleton components and lipids, is critical for maintaining microvilli integrity and function in secretion. Our results provide the first evidence that microvilli-derived extracellular vesicles contribute to Hedgehog long-range signaling activity highlighting their physiological significance in tissue development in vivo.

cell biology↗