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Vianello, S. D.

Publications and source records attributed to Vianello, S. D..

2 recordsLinked to original sources

Exploring and illustrating the mouse embryo: virtual objects to think and create with

The teaching, learning, communication, and practice of Developmental Biology require interested parties to be at ease with the considerable spatial complexity of the embryo, and with its evolution over time as it undergoes morphogenesis. In practice, the four dimensionality of embryonic development (space and time) calls upon strong visual-spatial literacy and mental manipulation skills, generally expected to be innate or to come through experience. Yet it has been argued that Developmental Biology suffers the most from available traditional media of communication and representation. To date, few resources exist to engage with the embryo in its 3D and 4D aspects, to communicate such aspects in ones work, and to facilitate their exploration in the absence of live observations. I here provide a collection of readily-usable volumetric models for all tissues and stages of mouse peri-implantation development as extracted from the eMouse Atlas Project (E5.0 to E9.0), as well as custom-made models of all pre-implantation stages (E0 to E4.0). These models have been converted to a commonly used 3D format (.stl), and are provided in ready-made files for digital exploration and illustration. Further provided is a step-by-step walkthrough on how to practically use these models for exploration and illustration using the free and open source 3D creation suite Blender. I finally outline possible further uses of these very models in outreach initiatives of varying levels, virtual and augmented reality applications, and 3D printing.

scientific communication and education

In vitro endoderm emergence and self-organisation in the absence of extraembryonic tissues and embryonic architecture

The endoderm is the cell lineage which gives rise in the embryo to the organs of the respiratory and gastrointestinal system. Uniquely, endodermal tissue does not just derive from descendants of the embryo proper (the epiblast) but instead arises from their gradual incorporation into an extraembryonic substrate (the visceral endoderm). Given the configuration of the early embryo, such a paradigm requires epiblast endodermal progenitors to negotiate embryonic compartments with very diverse epithelial character, a developmental contingency reflected by the fact that key early endodermal markers such as Foxa2 and Sox17 have been consistently found to be embedded within gene programmes involved in epithelialisation. To explore the underlying cell biology of embryonic endoderm precursors, and to explore the relationship between endoderm development, epithelial identity, and extraembryonic mixing, we leveraged Gastruloids, in vitro models of early development. These self-organising three-dimensional aggregates of mouse embryonic stem cells do not possess an extraembryonic component, nor do they appear to display typical tissue architecture. Yet, they generate cells expressing endodermal markers. By tracking these cells throughout in vitro development, we highlight a persistent and uninterrupted pairing between epithelial and endodermal identity, with FoxA2+/Sox17+ endoderm progenitors never transitioning through mesenchymal intermediates and never leaving the epithelial compartment in which they arise. We also document the dramatic morphogenesis of these progenitors into a macroscopic epithelial primordium extending along the entire anterior-posterior axis of the Gastruloid. Finally, we find that this primordium correctly patterns into broad domains of gene expression, and matures cells with anterior foregut, midgut, and hindgut identities within 7 days of culture. We thus postulate that Gastruloids may serve as a potential source of endodermal types difficult to obtain through classical 2D differentiation protocols.

developmental biology