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Biology subjects

Boni, A.

Publications and source records attributed to Boni, A..

4 recordsLinked to original sources

Open top multi sample dual view light sheet microscope for live imaging of large multicellular systems

Multicellular systems grow over the course of weeks from single cells to tissues or even full organisms composed of several thousands of cells, making live imaging of such samples challenging. To bridge these wide spatiotemporal scales, we present an open top dual view and dual illumination light sheet microscope dedicated for live imaging of large specimens at single cell resolution. The novel configuration of objectives together with a flexible and customizable multi-well mounting system combines dual view with high throughput multi-position imaging. We use the newly developed microscope to image a wide variety of samples and highlight its capabilities to gain quantitative single-cell information in large specimens such as mature intestinal organoids and gastruloids.

developmental biology↗

Multiscale light-sheet organoid imaging framework

Organoids provide an accessible in-vitro system to mimic the dynamics of tissue regeneration and development. However, long-term live-imaging of organoids remains challenging. Here we present an experimental and image-processing framework capable of turning long-term light-sheet imaging of intestinal organoids into digital organoids. The framework combines specific imaging optimization combined with data processing via deep learning techniques to segment single organoids, their lumen, cells and nuclei in 3D over long periods of time. By linking lineage trees with corresponding 3D segmentation meshes for each organoid, the extracted information is visualized using a web-based "Digital Organoid Viewer" tool allowing unique understanding of the multivariate and multiscale data. We also show backtracking of cells of interest, providing detailed information about their history within entire organoid contexts. Furthermore, we show cytokinesis failure of regenerative cells and that these cells never reside in the intestinal crypt, hinting at a tissue scale control on cellular fidelity.

cell biology↗

Embryonic organoids recapitulate early heart organogenesis

Organoids are powerful models for studying tissue development, physiology, and disease. However, current culture systems disrupt the inductive tissue-tissue interactions needed for the complex morphogenetic processes of native organogenesis. Here we show that mouse embryonic stem cells (mESCs) can be coaxed to robustly undergo the fundamental steps of early heart organogenesis with an in vivo-like spatiotemporal fidelity. These axially patterned embryonic organoids support the generation of cardiovascular progenitors, as well as first and second heart field compartments. The cardiac progenitors self-organize into an anterior domain reminiscent of a cardiac crescent before forming a beating cardiac tissue near a putative primitive gut-like tube, from which it is separated by an endocardial-like layer. These findings unveil the surprising morphogenetic potential of mESCs to execute key aspects of organogenesis through the coordinated development of multiple tissues. This platform could be an excellent tool for studying heart development in unprecedented detail and throughput.

developmental biology↗

High fidelity lineage tracing in mouse pre-implantation embryos using primed conversion of photoconvertible proteins

Accurate lineage reconstruction of mammalian pre-implantation development is essential for inferring the earliest cell fate decisions of mammalian development. Lineage tracing using global labeling techniques is complicated by increasing cell density and rapid embryo rotation, impeding automatic alignment and rendering accurate cell tracking of obtained four-dimensional imaging data sets highly challenging. Here, we exploit the advantageous properties of primed convertible fluorescent proteins (pr-pcFPs) to simultaneously visualize the global green and the photoconverted red population to minimize tracking uncertainties over prolonged time windows. Confined primed conversion of H2B-pr-mEosFP labeled nuclei combined with light-sheet imaging greatly facilitates segmentation, classification, and tracking of individual nuclei from the 4-cell stage up to the blastocyst. Using green and red labels as fiducial markers, we computationally correct for rotational and translational drift and accomplish high fidelity lineage tracing combined with a reduced data size - addressing majors concerns in the field of volumetric embryo imaging.

developmental biology↗