Cellular & Molecular Imaging

Manuscript abstract: Malaria transmission relies on sporozoite formation in the mosquito midgut and subsequent salivary gland invasion. Despite their importance, the cell biology of these processes remains poorly understood. We apply Mosquito Tissue Ultrastructure Expansion Microscopy (MoTissU-ExM), which physically expands infected mosquito tissues while preserving host and parasite ultrastructure. MoTissU-ExM reveals parasite structures and organelles, including features previously seen only by electron microscopy and novel structures not observed before. We use MoTissU-ExM to investigate sporozoite formation and salivary gland invasion, focusing on rhoptries - secretory organelles critical for host cell invasion. We establish a timeline for rhoptry biogenesis, show that two rhoptries are consumed during salivary gland invasion, and provide the first evidence that rhoptry pairs are specialized for different invasion events. We further characterize RON11 as the first protein involved in sporozoite rhoptry biogenesis; its disruption produces sporozoites that specifically fail to invade salivary gland epithelial cells, blocking parasite transmission. Dataset description: This dataset contains all microscopy data associated with the linked publication "Unlocking new understanding of Plasmodium sporozoite biology with expansion microscopy". All samples were prepared by ultrastructure-expansion microscopy (U-ExM). All samples were imaged on either a Zeiss LSM900 or LSM980 microscope, using either Airyscan-SR or Airyscan-MPLX modes. File names will include the magnification of the objective lens used as follows: 5x = EC Plan-Neofluar 5x/0.16NA Air 10x = Ziess Plan-Apochromat 10x/0.45NA air 20x = Ziess Plan-Apochromat 20x/0.8NA air 40x = Zeiss C-Apochromat 40x/1.2NA water-immersion autocorr M27 63x = Zeiss Plan-Apochromat 63x/1.4NA oil-immersion M27 Images are of mosquito tissues, or isolated parasites, from three Plasmodium species - berghei (Pb), falciparum (Pf), and yoelii (Py). Images are sorted and named as follows (folder name, file name) Plasmodium species > Tissue type/site of isolation > Parasite strain > Species abbreviation, MG/SG, Harvest day(dpi), Dye/Fluorophores (405nm -> 647nm), Objective, Image number (1->X), as (airyscan) For example, the third image taken of a P. berghei oocyst with the RON11iKD parasite line, that was harvested on Day 14 post infection, stained with NHS Ester AF405, BODIPY-FL, anti-Tubulin AF555, and Sytox Red, and imaged on the 40x-objective would be listed as follows: Plasmodium berghei > Infected midguts > RON11iKD > RON11KD MG 14dpi NHSBFlTub-SytR 40x 1 as The majority of images in this dataset are z-stacked images, but for many oocysts a single-slice image of the whole oocyst was taken. When this is the case, the single-slice image will be indicated with "SNAP". A list of the acronyms and abbreviations used in file names are as follows MG = Midgut SG = Salivary gland Spz = Sporozoite HC = Haemocoel dpi = Days post infection NHS = NHS Ester Alexa Fluor 405 BFl = Bodipy-FL-Ceramide BTRc = Bodipy-TR-Ceramide SytR = Sytox Deep Red Tub = anti-tubulin antibody CSP = anti-circumsporozoite protein antibody RAP1 = anti-rhoptry associated protein 1 antibody iKD = Inducible knockdown Ctrl = Control KD = Knockdown RON4 = anti-rhoptry neck protein 4 antibody GFP = anti-green fluorescent protein antibody WGA = Wheat germ aglutinnin BIP = anti-BiP antibody ERD2 = anti-ERD2 antibody

This dataset contains over 20000 images of Dipteran wings collected, mostly of mosquitos. Each image is accompanied by extensive metadata, accessible in the 00_metadata.* files. The dataset aims to facilitate research in wing geometric morphometry and support the development of machine learning models for advancing vector surveillance and research. It is a retrospective collection, harmonizing contributions from research projects conducted between 2008 and 2026. The detailed metadata on each sample and image is available in the 00_metadata.*. This table below will provide an overview of the scope and range of the collected metadata. Due to the retrospective nature of the dataset, images may vary significantly in aspects such as lighting, background, and capture conditions across different projects. Although extensive efforts were made to ensure comprehensive metadata, some entries remain incomplete. Missing metadata entries are marked as MISSING VALUE," while fields intentionally left blank are indicated with "-". For the full description of the dataset we refer to the associated publication: https://www.nature.com/articles/s41597-025-05043-3#Sec5

Ct3-GFP or Ct4-GFP inoculation of Arabidopsis roots

Ct3-GFP or Ct4-GFP inoculation of Arabidopsis roots

The human pregnane X receptor (PXR), a master regulator of drug metabolism, has important roles in intestinal homeostasis and abrogating inflammation. Existing PXR ligands have substantial off-target toxicity. Based on prior work that established microbial (indole) metabolites as PXR ligands, we proposed microbial metabolite mimicry as a novel strategy for drug discovery that allows to exploit previously unexplored parts of chemical space. Here we report functionalized indole-derivatives as first-in-class non-cytotoxic PXR agonists, as a proof-of-concept for microbial metabolite mimicry. The lead compound, FKK6, binds directly to PXR protein in solution, induces PXR specific target gene expression in, cells, human organoids, and mice. FKK6 significantly represses pro-inflammatory cytokine production cells and abrogates inflammation in human intestinal organoids and Caco-2 expressing the human PXR gene. These confocal images show FKK6 reduces NfKB translocation to the nucelus of intestinal organoids and caco-2 incubated with pro-inflammatory cocktail.

micrograph

Background Microsporidia sp. MB, a microsporidian symbiont found naturally in Anopheles mosquitoes, has potential as a novel malaria control tool since it can inhibit Plasmodium development and transmission. The most feasible MB-based Plasmodium control strategy would involve dissemination through live mosquito releases, or release of spores infective to mosquito larvae. To implement either strategy, establishment of stable mosquito colonies carrying MB at a high frequency is likely to be essential. The progeny of field caught An. gambiae s.l from Burkina Faso were isolated for individual egg laying and tested for MB. The progeny of the MB positive females were pooled and this process was repeated for multiple generations. The relative density of MB in different life stages and tissues of the An. coluzzii host was examined using a novel duplex qPCR assay. We also examined the impact of MB on fecundity through individualization for egg laying and counting of eggs. Finally, we examined laid eggs for presence of MB spores. Results Three An. coluzzii colonies and one An. gambiae s.l hybrid colony were established with high prevalence and density of MB and were maintained for more than two years with minimal intervention. MB prevalence and density was highest in eggs and adult females and lowest in L4 larvae; in adults density was highest in the gonads. Additionally, MB density increased in ovary samples following blood feeding which was likely due to the activation of sporogony. The production of spores is the reason why MB-carrying females lay more white non-hatching eggs and show a small reduction in fecundity. Conclusions Establishment of several stable MB carrying An. gambiae s.l colonies and understanding the impact of spores on fecundity are significant steps forward in developing MB as a malaria control tool.

In plants with indeterminate inflorescences, the number of flowers produced is determined by the activity of the inflorescence meristem. We combined quantitative imaging of the inflorescence meristem using light sheet microscopy with the manipulation of cytokinin levels and distribution to investigate how meristem activity is regulated. We further show that the duration of flowering and cytokinin signaling in the inflorescence meristem is influenced by nitrate availability. Taken together, these data suggest that cytokinin functions as a systemic signal that integrates information about ongoing reproductive effort and plant nutrient status to control flower production.

Manuscript abstract: Malaria transmission relies on sporozoite formation in the mosquito midgut and subsequent salivary gland invasion. Despite their importance, the cell biology of these processes remains poorly understood. We apply Mosquito Tissue Ultrastructure Expansion Microscopy (MoTissU-ExM), which physically expands infected mosquito tissues while preserving host and parasite ultrastructure. MoTissU-ExM reveals parasite structures and organelles, including features previously seen only by electron microscopy and novel structures not observed before. We use MoTissU-ExM to investigate sporozoite formation and salivary gland invasion, focusing on rhoptries - secretory organelles critical for host cell invasion. We establish a timeline for rhoptry biogenesis, show that two rhoptries are consumed during salivary gland invasion, and provide the first evidence that rhoptry pairs are specialized for different invasion events. We further characterize RON11 as the first protein involved in sporozoite rhoptry biogenesis; its disruption produces sporozoites that specifically fail to invade salivary gland epithelial cells, blocking parasite transmission. Dataset description: This dataset contains all microscopy data associated with the linked publication "Unlocking new understanding of Plasmodium sporozoite biology with expansion microscopy". All samples were prepared by ultrastructure-expansion microscopy (U-ExM). All samples were imaged on either a Zeiss LSM900 or LSM980 microscope, using either Airyscan-SR or Airyscan-MPLX modes. File names will include the magnification of the objective lens used as follows: 5x = EC Plan-Neofluar 5x/0.16NA Air 10x = Ziess Plan-Apochromat 10x/0.45NA air 20x = Ziess Plan-Apochromat 20x/0.8NA air 40x = Zeiss C-Apochromat 40x/1.2NA water-immersion autocorr M27 63x = Zeiss Plan-Apochromat 63x/1.4NA oil-immersion M27 Images are of mosquito tissues, or isolated parasites, from three Plasmodium species - berghei (Pb), falciparum (Pf), and yoelii (Py). Images are sorted and named as follows (folder name, file name) Plasmodium species > Tissue type/site of isolation > Parasite strain > Species abbreviation, MG/SG, Harvest day(dpi), Dye/Fluorophores (405nm -> 647nm), Objective, Image number (1->X), as (airyscan) For example, the third image taken of a P. berghei oocyst with the RON11iKD parasite line, that was harvested on Day 14 post infection, stained with NHS Ester AF405, BODIPY-FL, anti-Tubulin AF555, and Sytox Red, and imaged on the 40x-objective would be listed as follows: Plasmodium berghei > Infected midguts > RON11iKD > RON11KD MG 14dpi NHSBFlTub-SytR 40x 1 as The majority of images in this dataset are z-stacked images, but for many oocysts a single-slice image of the whole oocyst was taken. When this is the case, the single-slice image will be indicated with "SNAP". A list of the acronyms and abbreviations used in file names are as follows MG = Midgut SG = Salivary gland Spz = Sporozoite HC = Haemocoel dpi = Days post infection NHS = NHS Ester Alexa Fluor 405 BFl = Bodipy-FL-Ceramide BTRc = Bodipy-TR-Ceramide SytR = Sytox Deep Red Tub = anti-tubulin antibody CSP = anti-circumsporozoite protein antibody RAP1 = anti-rhoptry associated protein 1 antibody iKD = Inducible knockdown Ctrl = Control KD = Knockdown RON4 = anti-rhoptry neck protein 4 antibody GFP = anti-green fluorescent protein antibody WGA = Wheat germ aglutinnin BIP = anti-BiP antibody ERD2 = anti-ERD2 antibody

This submission contains cryo-SEM micrographs of S. lycopersicum x S. pennellii introgression line (IL) population. Ther terms "FEL" and "L" both refer to the first fully-expanded true leaf of the plants assayed.