Cellular & Molecular Imaging

The neglected tropical disease schistosomiasis impacts over 700 million people globally. Schistosoma mansoni, the trematode parasite that causes the most common type of schistosomiasis, requires planorbid pond snails of the genus Biomphalaria to support its larval development and transformation to the cercarial form that can infect humans. A greater understanding of neural signaling systems that are specific to the Biomphalaria intermediate host could lead to novel strategies for parasite or snail control. This study examined a Biomphalaria glabrata neural channel that is gated by the neuropeptide FMRF-NH2. The Biomphalaria glabrata FMRF-NH2 gated sodium channel (Bgl-FaNaC) amino acid sequence was highly conserved with FaNaCs found in related gastropods, especially the planorbid Planorbella trivolvis (91% sequence identity). In common with the P. trivolvis FaNaC, the B. glabrata channel exhibited a low affinity (EC50: 3 x 10-4 M) and high specificity for the FMRF-NH2 agonist. Its expression in the central nervous system, detected with immunohistochemistry and in situ hybridization, was widespread, with the protein localized mainly to neuronal fibers and the mRNA confined to cell bodies. Colocalization of the Bgl-FaNaC message with its FMRF-NH2 agonist precursor occurred in some neurons associated with male mating behavior. At the mRNA level, Bgl-FaNaC expression was decreased at 20 and 35 days post infection (dpi) by S. mansoni. Increased expression of the transcript encoding the FMRF-NH2 agonist at 35 dpi was proposed to reflect a compensatory response to decreased receptor levels. Altered FMRF-NH2 signaling could be vital for parasite proliferation in its intermediate host and may therefore present innovative opportunities for snail control.

Sample videos acquired with the InVision device. Videos are of schistosome miracidia swimming in a custom arena and can be used to develop and optimize tracking pipelines.

The images are tissue-based screens for autoantibodies in the cerebrospinal fluid of individuals with schizophrenia spectrum disorders (N=28 of 32) and healthy controls (N=27 of 32). For screening, sagittal adult mouse brain sections were incubated with cerebrospinal fluid at a 1:4 dilution and counterstained with anti-human IgG (488 channel). Blue = DAPI. Though all 32 subjects were screened by tissue-based assay, 4 and 5 schizophrenia spectrum and control files, respectively, were lost due to a hardware failure after the images had been evaluated as negative. Photobleaching of slides prevented faithful reacquisition of the images.

Intermuscular adipose tissue (IMAT) accumulation within skeletal muscle is associated with cardiometabolic disease, yet its spatial organization and molecular drivers remain poorly characterized. To map IMAT expansion within the quadriceps muscle architecture, spatial transcriptomics was performed on tissue sections from diet-induced obese male C57BL/6J mice fed a 60% kcal high fat diet (HFD) or 10% kcal low fat diet (LFD) for 20 weeks. The 10x Genomics Visium platform was used to generate spatially resolved gene expression profiles, which were integrated with immunofluorescence staining for Perilipin (adipocyte marker) and Laminin (muscle fiber boundaries) to relate transcriptional signatures to tissue morphology. This dataset enables spatially resolved investigation of gene expression changes associated with IMAT expansion in the context of diet-induced obesity.

Skeletal muscles display a unique plasticity, which responds to the rapid changes of the organism activity, nutritional habits, health conditions, genetic background, and other factors (Schiaffino and Reggiani, 2011; Sirago et al., 2022). The muscle is composed by multiple fibers that have different contractile characteristics. Skeletal muscle fibers differ one from another in the contractile apparatus composition, calcium handling properties, number of mitochondria, and morphological features (Schiaffino and Reggiani, 2011; Giacomello et al., 2020). We refer to the term “fiber profile” to all the features, such as MHC expression, morphology and metabolic activity, that characterize a single muscle fiber. In general, the isoforms of Myosin Heavy Chain (MyHC) expressed in a muscle fiber, are considered the gold standard in the correlation of the morphological, contractile, and metabolic properties. Interestingly, recent data show that both in rodent and human muscles, morphological and metabolic characteristics of fibers expressing the same MyHCs can significantly diverge. In the present project we investigated the different fiber profile of skeletal muscle fibers expressing MyHCI and IIa in soleus and exstensor digitorum longus muscles. This data was selected as part of the AI4Life Open Calls 2023 for image analysis consultation and deep-learning applications.

Macroscopic imaging and morphological assessment of mouse placentas at E9.5. Images are collected and analyzed to detect visible placental defects and developmental abnormalities.

The neglected tropical disease schistosomiasis impacts over 700 million people globally. Schistosoma mansoni, the trematode parasite that causes the most common type of schistosomiasis, requires planorbid pond snails of the genus Biomphalaria to support its larval development and transformation to the cercarial form that can infect humans. A greater understanding of neural signaling systems that are specific to the Biomphalaria intermediate host could lead to novel strategies for parasite or snail control. This study examined a Biomphalaria glabrata neural channel that is gated by the neuropeptide FMRF-NH2. The Biomphalaria glabrata FMRF-NH2 gated sodium channel (Bgl-FaNaC) amino acid sequence was highly conserved with FaNaCs found in related gastropods, especially the planorbid Planorbella trivolvis (91% sequence identity). In common with the P. trivolvis FaNaC, the B. glabrata channel exhibited a low affinity (EC50: 3 x 10-4 M) and high specificity for the FMRF-NH2 agonist. Its expression in the central nervous system, detected with immunohistochemistry and in situ hybridization, was widespread, with the protein localized mainly to neuronal fibers and the mRNA confined to cell bodies. Colocalization of the Bgl-FaNaC message with its FMRF-NH2 agonist precursor occurred in some neurons associated with male mating behavior. At the mRNA level, Bgl-FaNaC expression was decreased at 20 and 35 days post infection (dpi) by S. mansoni. Increased expression of the transcript encoding the FMRF-NH2 agonist at 35 dpi was proposed to reflect a compensatory response to decreased receptor levels. Altered FMRF-NH2 signaling could be vital for parasite proliferation in its intermediate host and may therefore present innovative opportunities for snail control.

The cyanoHAB forming cyanobacteria Microcystis and Planktothrix frequently produce high intracellular amounts of microcystins (MCs) or anabaenopeptins (APs). In this study, chemically modified MCs and APs have been localized on a subcellular level in Microcystis and Planktothrix applying copper-catalyzed alkyne-azide cycloaddition (CuACC). For this purpose, three different non-natural amino acids carrying alkyne or azide moieties were fed to individual P. agardhii strains No371/1 and CYA126/8 as well as to M. aeruginosa strain Hofbauer showing promiscuous incorporation of various amino acid substrates during non-ribosomal peptide synthesis (NRPS). Moreover, CYA126/8 peptide knock-out mutants and non-toxic strain Synechocystis PCC6803 were processed under identical conditions. Simultaneous labelling of modified peptides with ALEXA405 and ALEXA488 and lipid staining with BODIPY 505/515 were performed to investigate the intracellular location of the modified peptides. Pearson correlation coefficients (PCC) obtained from confocal images were calculated between the different fluorophores and the natural autofluorescence (AF), and between labelled modified peptides and dyed lipids to investigate the spatial overlap between peptides and the photosynthetic complex, and between peptides and lipids. Overall, labelling of modified MCs (M. aeruginosa) and APs (P. agardhii) using both fluorophores revealed in-creased intensity in MC/AP producing strains. For Synechocystis lacking NRPS, no labelling using either ALEXA405 or ALEXA488 was observed. Lipid staining in M. aeruginosa and Synechocystis was intense while in Planktothrix it was more variable. When compared with AF, both modified peptides and lipids showed a heterologous distribution. In comparison, the correlation between stained lipids and labelled peptides was not increased suggesting a reduced spatial overlap.

Female fertility depends on a finite pool of oocytes that depletes during aging, yet the spatiotemporal dynamics of this depletion remain poorly understood. Traditional methods obscure the 3D-architecture of the ovary, limiting quantitative insights. Here, we combine light-sheet microscopy, artificial intelligence (AI)-driven segmentation, and mathematical modeling to map over 85,000 oocytes in whole-ovaries across the reproductive lifespan in mouse. We find that newly-activated oocytes represent a fixed fraction of total oocyte pool despite an age-related decline in oocyte numbers. Spatial analysis revealed that oocytes are enriched along the lateral ovarian axis, and local oocyte density positively correlates with activation. We also uncover a bimodal distribution of oocyte sizes, suggesting a bottleneck during oogenesis. Finally, a differential equation-based model captures the kinetics of oocyte activation and loss. Our findings establish a quantitative framework for understanding ovarian aging and suggest that an organ-scale regulatory mechanism coordinates the age-related decline in oocyte numbers.

Sample videos acquired with the InVision device. Videos are of schistosome miracidia swimming in a custom arena and can be used to develop and optimize tracking pipelines.