Coleon, A. | Search bioRxiv

bioRxiv2025

RNA2seg: a generalist model for cell segmentation in image-based spatial transcriptomics

Imaging-based spatial transcriptomics (IST) enables high-resolution spatial mapping of RNA species. A key challenge in IST is accurate cell segmentation to assign each RNA molecule to the right cell. Here, we present RNA2seg, a novel segmentation algorithm trained on over 4 million cells from MERFISH and CosMx datasets across seven organs using a teacher-student training scheme. RNA2seg integrates RNA point clouds and all available membrane and nuclear stainings. Validation on manually annotated data shows superior performance including in zero-shot and few-shot settings. The method is available as a documented pip package: https://github.com/fish-quant/rna2seg.

bioinformatics↗

bioRxiv2024

Hamsters with long Covid exhibits a neurodegenerative signature in the brainstem

After infection with SARS-CoV-2, patients may present with one or more symptoms that appear or persist over time, including fatigue, respiratory, cardiovascular and neurological disorders. Neurological symptoms include anxiety, depression and impaired short-term memory. However, the exact underlying mechanisms of long Covid are not yet decrypted. Using the golden hamster as a model, we provide further evidence that SARS-CoV-2 is neuroinvasive and can persist in the central nervous system, as we found viral RNA and replicative virus in the brainstem after 80 days of infection. Infected hamsters presented a neurodegenerative signature in the brainstem, with overexpression of innate immunity genes, impacted dopaminergic and glutamatergic synapses, altered energy metabolism. Finally, the infected hamsters manifested persistent signs of depression and impaired short-term memory, as well as late-onset signs of anxiety, as a valuable model to study long Covid. Conclusively, we provide evidence that virus-related and neurodegenerative and immunometabolic mechanisms coexist in the brainstem of infected hamsters and contribute to the manifestation of neuropsychiatric and cognitive symptoms. HighlightsO_LISARS-CoV-2 infects and persists in the brainstem of intranasally-inoculated hamsters C_LIO_LIPersistent neuropsychiatric and cognitive consequences are observed in SARS-CoV-2-infected hamsters C_LIO_LIThe brainstem present distinct transcriptome profiles in acute and in long Covid C_LIO_LIThe dopaminergic and glutamatergic systems are affected in long Covid C_LIO_LIThe SARS-CoV-2 infection affects the expression of genes related to neurodegenerative processes in acute and in long Covid C_LI

pathology↗