Cellular & Molecular Imaging

Tara Expeditions are global scientific voyages that probe morphological and molecular diversity, evolution and ecology of marine plankton to explore how they are impacted by changes in the Earth's climate. The first expeditions collected samples of marine plankton containing viruses, bacteria, archaea, protists and planktonic metazoans living in the photic layer of the world's oceans. These expeditions, the first taking place between 2009 and 2013, include Tara Oceans: a global view, and Tara Oceans Polar Circle, both of which followed the same sampling protocol. This dataset includes 1074 pictures of 284 planktonic taxa (mainly microalgae and other Ciliate and Radiolarian protists) collected from the vicinity of the Marquesas Islands in the Southern Pacific Ocean during the Tara Oceans expedition. Multiple samples particularly of the size fractions 5-20 and 20 180 um from four sites and two depths were processed with different methods and studied in detail using scanning electron microscopy.

Sagittal section images showing cross-section of the stomodeal valve at point of greatest opening of 15 sand flies (Lutzomyia longipalpis) at various stages of infection with Leishmania mexicana. The images show the effects of an infection and of a second blood meal on the morphology of the foregut and midgut (especially thoracic midgut) compared to uninfected, control flies. Three flies were imaged by micro-CT scan in each of five groups: T7CON flies were 7 days after a non-infected blood meal. T9INF and T12INF flies were 9 and 12 days, respectively, after an infected blood meal. T6INF+ and T9INF+ flies were 6 and 9 days, respectively after an infected bloodmeal and 1 and 4 days, respectively, after a second, non-infected blood meal. The data are discussed in a paper published on 27th August 2021 in PLoS NTDs, which is accessible through the following link: https://doi.org/10.1371/journal.pntd.0009682

This dataset comprises the raw data associated with Wong et al., EMBO J., 2024. "Regulation of centrosome size by the cell cycle oscillator in Drosophila embryos". This dataset (approximately 900Gb in total) tracks the behavior of individual centrosomes (labelled with different centrosome markers) in early Drosophila embryos during nuclear cycles 11-13 under various conditions. The datasets are organised to align with each individual Figure shown in the paper. The paper abstract is: Mitotic centrosomes assemble when centrioles recruit large amounts of pericentriolar material (PCM) around themselves. In early C. elegans embryos, mitotic centrosome size appears to be set by the limiting amount of a key component. In Drosophila syncytial embryos, thousands of mitotic centrosomes are assembled as the embryo proceeds through 13 rounds of rapid nuclear division, driven by a core cell-cycle oscillator. These divisions slow during nuclear cycles 11-13, and we find that centrosomes respond by reciprocally decreasing their growth rate, but increasing their growth period—so that they grow to a relatively consistent size at each cycle. At the start of each cycle, moderate CCO activity initially promotes centrosome growth, in part by stimulating Polo/PLK1 recruitment to centrosomes. Later in each cycle, high CCO activity inhibits centrosome growth by suppressing the centrosomal recruitment and/or maintenance of centrosome proteins. Thus, in fly embryos, mitotic centrosome size appears to be regulated predominantly by the core cell-cycle oscillator, rather than by the depletion of a limiting component.

This record contains the raw and reconstructed imaging data (imaris) underlying the cortical organoid experiments in Sheu et al., "Coupled transcriptomic divergence establishes a human-specific synaptic glial precursor state." Cortical organoids derived from human, chimpanzee, and gorilla pluripotent stem cells were fixed at two culture timepoints (DIV60 and DIV160) and immunostained for the NMDA receptor subunit GluN2B and the postsynaptic scaffold PSD-95, together with the oligodendrocyte precursor markers PDGFRα. Confocal z-stacks were acquired and volumetrically reconstructed to quantify synaptic protein signal volume and puncta density within the PDGFRα-positive cellular volume. Contents raw_tiff/ — unmodified confocal z-stacks. imaris/ — processed Imaris (.ims) files containing surface and spot reconstructions used for volumetric quantification. quantification_source_data/ — per-cell signal volume and puncta density values exported from Imaris; these are the values plotted in the manuscript figures and tested in Supplementary Table S5.

Asymmetric localization of oskar RNP granules to the oocyte posterior is crucial for abdominal patterning and germline formation in the Drosophila embryo. We show that oskar RNP granules in the oocyte are condensates with solid-like physical properties. Using purified oskar RNA and scaffold proteins Bruno and Hrp48, we confirm in vitro that oskar granules undergo a liquid-to-solid phase transition. Whereas the liquid phase allows RNA incorporation, the solid phase precludes incorporation of additional RNA while allowing RNA-dependent partitioning of client proteins. Genetic modification of scaffold granule proteins, or tethering the intrinsically disordered region of human Fused in Sarcoma (FUS) to oskar mRNA, allowed modulation of granule material properties in vivo. The resulting liquid-like properties impaired oskar localization and translation with severe consequences on embryonic development. Our study reflects how physiological phase transitions shape RNA-protein condensates to regulate localization and expression of a maternal RNA that instructs germline formation.

In Drosophila male gonads, niche-derived Decapentaplegic (Dpp) has a role in maintaining stem cells in close proximity but the range of Dpp diffusion and its role has never been tested in the differentiating cells spaced one-cell layer away. Here, using genetically encoded nanobodies called Morphotraps, we physically block Dpp diffusion without interfering with niche-stem cell signaling and find that a diffusible fraction of Dpp is required to ensure differentiation of GSC daughter cells, opposite of its role in maintenance of GSC in the niche. Our work provides an example in which a soluble niche ligand induces opposed cellular responses in stem cells versus differentiating descendants to ensure spatial control of the niche, which may be a common mechanism to regulate tissue homeostasis.

Two photon microscopy time series and lightsheet microscopy z-stack and time series of early Drosophila embryogenesis during posterior midgut invagination.

Live cell imaging movies and IHC data from Drosophila Neurons together with computer simulation results.

Live cell imaging movies and IHC data from Drosophila Neurons together with computer simulation results.

raw data of manuscript