Myelination generates aberrant ultrastructure that is resolved by microglia

The Journal of Cell Biology, Journal Year: 2022, Volume and Issue: 222(3)

Published: Dec. 22, 2022

To enable rapid propagation of action potentials, axons are ensheathed by myelin, a multilayered insulating membrane formed oligodendrocytes. Most the myelin is generated early in development, resulting generation long-lasting stable structures. Here, we explored structural and dynamic changes central nervous system during development. achieve this, performed an ultrastructural analysis mouse optic nerves serial block face scanning electron microscopy (SBF-SEM) confocal time-lapse imaging zebrafish spinal cord. We found that undergoes extensive postnatal Myelin degeneration profiles were engulfed phagocytosed microglia using exposed phosphatidylserine as one “eat me” signal. In contrast, retractions entire sheaths occurred independently involved uptake oligodendrocyte itself. Our findings show development inaccurate process associated with aberrant features require substantial refinement.

Language: Английский

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Deep learning in CRISPR-Cas systems: a review of recent studies

Frontiers in Bioengineering and Biotechnology, Journal Year: 2023, Volume and Issue: 11

Published: July 3, 2023

In genetic engineering, the revolutionary CRISPR-Cas system has proven to be a vital tool for precise genome editing. Simultaneously, emergence and rapid evolution of deep learning methodologies provided an impetus scientific exploration genomic data. These concurrent advancements mandate regular investigation state-of-the-art, particularly given pace recent developments. This review focuses on significant progress achieved during 2019–2023 in utilization predicting guide RNA (gRNA) activity system, key element determining effectiveness specificity editing procedures. this paper, analytical overview contemporary research is provided, with emphasis placed amalgamation artificial intelligence engineering. The importance our underscored by necessity comprehend rapidly evolving their potential impact system. By analyzing literature, highlights achievements emerging trends integration systems, thus contributing future direction essential interdisciplinary area.

Language: Английский

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Xenopus leads the way: Frogs as a pioneering model to understand the human brain

genesis, Journal Year: 2020, Volume and Issue: 59(1-2)

Published: Dec. 27, 2020

From its long history in the field of embryology to recent advances genetics, Xenopus has been an indispensable model for understanding human brain. Foundational studies that gave us our first insights into major embryonic patterning events serve as a crucial backdrop newer avenues investigation organogenesis and organ function. The vast array tools available laevis tropicalis allows interrogation developmental phenomena at all levels, from molecular behavioral, application CRISPR technology enabled disorder risk genes higher-throughput manner. As only tetrapod which stages are easily manipulated observed, frogs provide unique opportunity study development earliest stages. All these features make premier studying brain, notoriously complex process demands fertilization beyond. Importantly, core processes brain conserved between human, underlining advantages this model. This review begins by summarizing discoveries made amphibians form cornerstones vertebrate neurodevelopmental biology goes on discuss have catapulted relation disease. we engage new era patient-driven gene discovery, offers exceptional potential uncover underlying disorders move towards rational drug design.

Language: Английский

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Xenopus laevis (Daudin, 1802) as a Model Organism for Bioscience: A Historic Review and Perspective

Biology, Journal Year: 2023, Volume and Issue: 12(6), P. 890 - 890

Published: June 20, 2023

In vitro systems have been mainly promoted by authorities to sustain research following the 3Rs principle, but continuously increasing amounts of evidence point out that in vivo experimentation is also extreme relevance. Xenopus laevis, an anuran amphibian, a significant model organism study evolutionary developmental biology, toxicology, ethology, neurobiology, endocrinology, immunology and tumor biology; thanks recent development genome editing, it has acquired relevant position field genetics. For these reasons, X. laevis appears be powerful alternative zebrafish for environmental biomedical studies. Its life cycle, as well possibility obtain gametes from adults during whole year embryos fertilization, allows experimental studies several biological endpoints, such gametogenesis, embryogenesis, larval growth, metamorphosis and, course, young adult stages. Moreover, with respect invertebrate even vertebrate animal models, displays higher degree similarity mammals. Here, we reviewed main available literature on use biosciences inspired Feymann’s revised view, “Plenty room biology at bottom,” suggest very useful all possible

Language: Английский

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Lrp5 Mutant and Crispant Zebrafish Faithfully Model Human Osteoporosis, Establishing the Zebrafish as a Platform for CRISPR-Based Functional Screening of Osteoporosis Candidate Genes

Journal of Bone and Mineral Research, Journal Year: 2020, Volume and Issue: 36(9), P. 1749 - 1764

Published: Dec. 1, 2020

ABSTRACT Genomewide association studies (GWAS) have improved our understanding of the genetic architecture common complex diseases such as osteoporosis. Nevertheless, to attribute functional skeletal contributions candidate genes osteoporosis-related traits, there is a need for efficient and cost-effective in vivo testing. This can be achieved through CRISPR-based reverse screens, where phenotyping traditionally performed stable germline knockout (KO) mutants. Recently it was shown that first-generation (F0) mosaic mutant zebrafish (so-called crispants) recapitulate phenotype KOs. To demonstrate feasibility validation osteoporosis crispant screening, we compared KO model lrp5 gene. In humans, recessive loss-of-function mutations LRP5, co-receptor Wnt signaling pathway, cause osteoporosis-pseudoglioma syndrome. addition, several GWAS identified LRP5 major risk locus phenotypes. this study, showed early stage larvae display decreased notochord mineralization malformations head cartilage. Quantitative micro-computed tomography (micro-CT) scanning mass-spectrometry element analysis adult skeleton revealed vertebral bone volume mineralization, hallmark features Furthermore, regenerating fin tissue displayed reduced activity adults. We next mutants with crispants. Next-generation sequencing mean out-of-frame mutation rate 76%, resulting strongly levels Lrp5 protein. These crispants generally milder but nonetheless highly comparable similarly pathway response conclusion, show faithful modeling LRP5-related primary screening promising approach rapid genes. © 2021 The Authors. Journal Bone Mineral Research published by Wiley Periodicals LLC on behalf American Society (ASBMR).

Language: Английский

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Deep learning is widely applicable to phenotyping embryonic development and disease

Development, Journal Year: 2021, Volume and Issue: 148(21)

Published: Nov. 1, 2021

ABSTRACT Genome editing simplifies the generation of new animal models for congenital disorders. However, detailed and unbiased phenotypic assessment altered embryonic development remains a challenge. Here, we explore how deep learning (U-Net) can automate segmentation tasks in various imaging modalities, quantify phenotypes renal, neural craniofacial Xenopus embryos comparison with normal variability. We demonstrate utility this approach polycystic kidneys (pkd1 pkd2) dysmorphia (six1). highlight toto light-sheet microscopy facilitates accurate reconstruction brain structures within X. tropicalis upon dyrk1a six1 loss function or treatment retinoic acid inhibitors. These tools increase sensitivity throughput evaluating developmental malformations caused by chemical genetic disruption. Furthermore, provide library pre-trained networks instructions applying to reader's own datasets. versatility, precision scalability network phenotyping on disease models. By combining learning, framework higher-throughput characterization model organisms. This article has an associated ‘The people behind papers’ interview.

Language: Английский

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Crispant analysis in zebrafish as a tool for rapid functional screening of disease-causing genes for bone fragility

Published: Jan. 2, 2025

Heritable Fragile Bone Disorders (FBDs) encompass a spectrum of conditions, from widespread multifactorial to rare monogenic diseases, all characterized by an elevated risk fractures. The process validating causative genes and elucidating their pathogenic mechanisms remains daunting resource-intensive task. In this study, we evaluated the feasibility semi-high throughput zebrafish screening platform for rapid validation in vivo functional testing candidate disease-causing wide range heritable FBDs. Six associated with severe recessive forms Osteogenesis Imperfecta (OI) four bone mineral density (BMD), key osteoporosis indicator, identified through genome-wide association studies (GWAS) were selected. crispant approach, based on CRISPR/Cas9 technology, was used phenotype directly F0 mosaic founder zebrafish. Next-Generation Sequencing (NGS) analysis revealed mean indel efficiency 88% across ten different crispants, indicating high proportion knock-out alleles thus resembling stable models. We applied multiple techniques evaluate skeletal characteristics at 7, 14 90 days post-fertilization (dpf), including microscopy osteoblast reporter visualization mineralization Alizarin Red S staining, microCT quantitative analysis. While larval crispants exhibited variable differences osteoblast-positive mineralized surface areas, adult-stage displayed more pronounced consistent phenotypes. Notably, developed malformed neural haemal arches, majority presenting vertebral fractures fusions, some showing significant alterations volume density. addition, aldh7a1 mbtps2 experienced increased mortality due deformities. RT-qPCR differentiation formation markers stages indicated differential expression osteogenic bglap col1a1a substantial portion hinting utility as biomarkers FBD screening. summary, our findings demonstrate that offers viable efficient strategy assessment genes. advocate novel comprehensive approach integrates various evaluates distinct molecular profiles developmental adult stages. This methodology has potential provide new insights into role these biology.

Language: Английский

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Behavioural pharmacology predicts disrupted signalling pathways and candidate therapeutics from zebrafish mutants of Alzheimer’s disease risk genes

Published: Jan. 14, 2025

By exposing genes associated with disease, genomic studies provide hundreds of starting points that should lead to druggable processes. However, our ability systematically translate these findings into biological pathways remains limited. Here, we combine rapid loss-of-function mutagenesis Alzheimer’s risk and behavioural pharmacology in zebrafish predict disrupted processes candidate therapeutics. FramebyFrame, expanded package for the analysis larval behaviours, revealed decreased night-time sleep was common F0 knockouts all four late-onset tested. We developed an online tool, ZOLTAR, which compares any fingerprint a library fingerprints from larvae treated 3,677 compounds. ZOLTAR successfully predicted sorl1 mutants have serotonin signalling identified betamethasone as drug normalises excessive day-time presenilin-2 knockout minimal side effects. Predictive offers general framework rapidly link disease-associated pathways.

Language: Английский

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Crispant analysis in zebrafish as a tool for rapid functional screening of disease-causing genes for bone fragility

eLife, Journal Year: 2025, Volume and Issue: 13

Published: Jan. 16, 2025

Heritable fragile bone disorders (FBDs), ranging from multifactorial to rare monogenic conditions, are characterized by an elevated fracture risk. Validating causative genes and understanding their mechanisms remain challenging. We assessed a semi-high throughput zebrafish screening platform for rapid in vivo functional testing of candidate FBD genes. Six linked severe recessive osteogenesis imperfecta (OI) four associated with mineral density (BMD) genome-wide association studies were analyzed using CRISPR/Cas9-based crispant F0 mosaic founder zebrafish. Next-generation sequencing confirmed high indel efficiency (mean 88%), mimicking stable knock-out models. Skeletal phenotyping at 7, 14, 90 days post-fertilization (dpf) microscopy, Alizarin Red S staining, microCT was performed. Larval crispants showed variable osteoblast mineralization phenotypes, while adult displayed consistent skeletal defects, including malformed neural haemal arches, vertebral fractures fusions, altered volume density. In addition, aldh7a1 mbtps2 experienced increased mortality due deformities. RT-qPCR revealed differential expression osteogenic markers bglap col1a1a , highlighting biomarker potential. Our results establish as robust tool gene validation, combining molecular analyses across developmental stages uncover novel insights into functions biology.

Language: Английский

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Behavioural pharmacology predicts disrupted signalling pathways and candidate therapeutics from zebrafish mutants of Alzheimer’s disease risk genes

eLife, Journal Year: 2025, Volume and Issue: 13

Published: Jan. 27, 2025

By exposing genes associated with disease, genomic studies provide hundreds of starting points that should lead to druggable processes. However, our ability systematically translate these findings into biological pathways remains limited. Here, we combine rapid loss-of-function mutagenesis Alzheimer’s risk and behavioural pharmacology in zebrafish predict disrupted processes candidate therapeutics. FramebyFrame , expanded package for the analysis larval behaviours, revealed decreased night-time sleep was common F0 knockouts all four late-onset tested. We developed an online tool, ZOLTAR which compares any fingerprint a library fingerprints from larvae treated 3677 compounds. successfully predicted sorl1 mutants have serotonin signalling identified betamethasone as drug normalises excessive day-time presenilin-2 knockout minimal side effects. Predictive offers general framework rapidly link disease-associated pathways.

Language: Английский

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