Understanding how development is coordinated in multiple tissues and gives rise to fully functional organs or whole organisms necessitates microscopy tools. Over the last decade numerous advances have been made in live-imaging, enabling high resolution imaging of whole organisms at cellular resolution. Yet, these advances mainly rely on mounting the specimen in agarose or aqueous solutions, precluding imaging of organisms whose oxygen uptake depends on ventilation.

Engineers from the Institut Curie and Institut Jacques Monod implemented a multi-view multi-scale microscopy strategy based on confocal spinning disk microscopy, called Multi-View confocal microScopy (MuViScopy).

MuViScopy enables live-imaging of multiple organs with cellular resolution using sample rotation and confocal imaging without the need of sample embedding. They illustrated the capacity of MuViScopy by live-imaging Drosophila melanogaster pupal development throughout metamorphosis, highlighting how internal organs are formed and multiple organ development is coordinated. They foresee that MuViScopy will open the path to better understand developmental processes at the whole organism scale in living systems that require gas exchange by ventilation.

3D fusion reconstruction of eight different angles at 10x magnification. Animation of a 3D reconstruction after fusion of images acquired from eight angles by the MuViScope of an Ecad:3xGFP Drosophila pupa at 28 hAPF with a 10x objective. The animation starts with a 180° rotation along the A-P axis and then sequentially shows the eight different angles from a top view: 0° (red), 45° (orange), 90° (yellow), 135° (green), 180° (light blue), 225° (dark blue), 270° (purple) and 315° (pink). Fusion was performed using Huygens Fuser (SVI) and 3D visualization with Imaris software. The acquisition parameters are detailed in Table S1. Scale bar: 200 μm.

Olivier Leroy, Eric van Leen, Philippe Girard, Aurélien Villedieu, Christian Hubert, Floris Bosveld, Yohanns Bellaïche, Olivier Renaud; Multi-view confocal microscopy enables multiple organ and whole organism live-imaging. Development 15 February 2022; 149 (4): dev199760. doi: https://doi-org.insb.bib.cnrs.fr/10.1242/dev.199760

The MuViScope was co-funded by France-BioImaging.

Quantifying translation in space and time during development

During development, precise control of gene expression allows the reproducible establishment of patterns, leading to the formation of organs at the right time and place.

The establishment of developmental patterns has been primarily studied at the transcriptional level. In comparison, the fate of these transcripts received little attention.

Dufourt*, Bellec* et al deployed the SunTag labeling method to image the dynamics of translation of individual mRNA molecules in living Drosophila embryos. This led to the discovery of translation factories and unmasked important heterogeneities in the efficiency of translation between identical mRNAs, demonstrating a novel layer of fine-tuning of gene expression.

Imaging translation dynamics in live embryos reveals spatial heterogeneities.

Dufourt J, Bellec M, Trullo A, Dejean M, De Rossi S, Favard C, Lagha M.

Science. 29 avril 2021 doi: 10.1126/science.abc3483.

Contact:

Mounia Lagha (CNRS)

mounia.lagha@igmm.cnrs.fr

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