Zebrafish最新文献

Brazil has emerged as a significant contributor to the global zebrafish (Danio rerio) research community, yet a comprehensive analysis of its national output, collaboration networks, and thematic focus has been lacking. This study provides a systematic bibliometric analysis of 801 Brazilian-corresponding articles published from 2020 to 2025, representing ∼2.7% of global production. Our findings reveal a marked concentration of scientific output, with the South and Southeast regions contributing ∼65% of national publications, led by the states of Rio Grande do Sul (24.8%) and São Paulo (20.4%). Despite this geographic disparity, a robust and integrative national collaboration network connects all regions, with an average 34% of publications involving interstate co-authorship. International partnerships are substantial (30.4% of output), led by the Southeast and South regions, and feature distinct geographic profiles, including the Central-West's links with South Asia. The field is characterized by a strong applied focus, with Toxicology (34% of studies), Pharmacology (18.3%), and Neuroscience (15%) dominating the research landscape, aligning with the predominant use of the adult zebrafish model (64%). Publication is heavily concentrated in environmental and toxicology journals, with nearly half of all output published by Elsevier (47%). These results map a dynamic, collaborative, and thematically focused national research community that is resilient yet faces persistent regional inequalities. The study establishes a critical baseline for understanding the structure and drivers of Brazilian science in a globally relevant model organism.

The study investigates the role of cobalt chloride (CoCl₂), a hypoxia-inducing agent, in promoting tissue regeneration using zebrafish as a model system. Caudal fins of adult zebrafish were amputated and transdermally exposed to 1% CoCl₂. The extent of fin regeneration and the neovascularization process at the growth front were analyzed. CoCl₂ exposure significantly enhanced regeneration compared with controls, with increased fin length and more prominent blood vessel sprouting and anastomosis. Molecular and proteomics analyses revealed an upregulation of angiogenic and pro-angiogenic factors, particularly Vascular Endothelial Growth Factor (VEGF). To verify the role of VEGF in CoCl₂-mediated tissue regeneration, the amputated fins were exposed to inhibitors such as genistein and SU5416. These results suggest that CoCl₂ promotes tissue regrowth and wound healing by stimulating angiogenesis. The findings highlight the therapeutic potential of CoCl₂ in enhancing regeneration and wound repair through the HIF-1α/VEGF signaling pathway, with potential implications for treating ischemic wounds.

The use of zebrafish (Danio rerio) larva as an experimental model has gained a lot of interest in epilepsy research due to its multiple advantages over mammalian models. The present study investigated the time-dependent expression of c-fos, an immediate early gene, and a marker of neuronal activation, following pentylenetetrazole (PTZ)-induced seizures in zebrafish larvae at 7-day post-fertilization . The larvae were exposed to 8 mM PTZ for a 15-min period, transferred to fish system water, and processed for c-Fos expression analysis at 15, 30, 45, 60, and 90 min of the start of the experiment. c-fos mRNA and c-Fos protein levels were quantified, and Pearson correlation analysis was conducted to assess their relationship. PTZ exposure induced seizure-like behavior and resulted in a dynamic temporal expression of c-Fos, with both mRNA and protein achieving peak levels at 45 min and declining by 90 min. This approach applied a fixed exposure duration and defined post-exposure time points, which allowed a more accurate temporal profiling. The observed peak expression at 45 min suggested an optimal window for evaluating c-Fos expression in the PTZ-induced seizures model of zebrafish larva. These findings provided a valuable reference for selecting experimental endpoints in zebrafish larva seizure studies and enhanced the reliability of c-Fos as a marker of neuronal activation.

Chorions, also known as egg membranes, form quickly after fertilization and play a role in subsequent embryonic development in fish. While the enzymatic hardening of the chorion due to the release of cortical alveoli (CA) components by the exocytosis of CA has been well-demonstrated, the initiation mechanism of this process has remained unresolved. Knockout lines with the prss59.1 trypsin paralog gene exhibited abnormalities in chorion elevation. Prss59.1 has been shown to be expressed on the chorion's surface. Therefore, we hypothesized that a trypsin-like enzyme expressed on the chorion could trigger chorion elevation. In this study, we attempted to improve the effectiveness of Hank's solution at preventing chorion elevation. By adjusting the concentration of the solution's contents, we developed a modified Hank's solution that can stop chorion elevation almost completely. Using this solution, we demonstrated that trypsin can induce chorion elevation. These results support our hypothesis that a trypsin-like enzyme initiates chorion elevation. This assay method can be used for the further analysis of the chorion elevation mechanism.

DaniocellDesktop is a cross-platform interactive desktop application designed to facilitate reanalysis of a previously published 462,243-cell single-cell RNAseq dataset that profiled cell-type-specific gene expression across the first 5 days of wild-type zebrafish development. DaniocellDesktop enables custom redefinition of cell populations, identification of differentially expressed genes, and generation of several types of publication-ready plots to show gene expression patterns, gene co-expression patterns, and gene expression over time within these previously published data without requiring any specific programming knowledge. This software is available from https://daniocell.nichd.nih.gov/desktop/.

The optokinetic response (OKR) is a widely used measure of visual and neurological function in zebrafish (Danio rerio). In this study, we employed a simple and cost-effective OKR assay system for adult zebrafish utilizing a mobile phone and a stereomicroscope. The setup was validated by comparing control fish with those exposed to light-induced retinal degeneration (LIRD), demonstrating significantly impaired OKR responses. This custom-made setup offers valuable applications in visual neuroscience, disease modeling, and drug discovery.

The rapid advancement of nuclear and mitochondrial genomic editing tools has created an urgent need for efficient, nonlethal larval genotyping methods in zebrafish (Danio rerio) research. This study optimizes and validates a nondestructive proteinase K digestion method for mitochondrial and nuclear DNA genotyping while characterizing its impact on larval survival and gene expression. Using optimized protocol parameters, we demonstrate successful amplification of different mitochondrial and nuclear genetic loci with consistently high sensitivity. Molecular validation through PCR, restriction fragment length polymorphism analysis, and Sanger sequencing confirmed the specificity and reliability of the extracted DNA. The method successfully detected C-to-T base edits in the mt-tl1 gene introduced using the FusX TALE Base editor system, demonstrating its applicability to gene editing studies. Both 48-well and optimized 96-well formats were used, enabling this approach to be deployed at scale. This optimized method enables researchers to correlate genotypes with phenotypes in longitudinal studies while maintaining specimen viability, particularly valuable for investigating early-onset mitochondrial diseases, and utilizes standard laboratory equipment and reagents, facilitating widespread adoption in zebrafish research while adhering to ethical principles in reducing animal mortality.

Oral gavage is ideal for studies requiring controlled dose delivery and timing, such as repeated dosing and longitudinal analysis, as shown in this study. An anesthesia-free gavage technique was used to administer daily estradiol doses to adult zebrafish for 40 days to evaluate reproductive toxicity (developmental and reproductive toxicity one stage). Results showed that neither estradiol administration nor the gavage method caused stress or injury, but both impacted reproductive capacity in a dose-dependent manner. Females exposed to the drug exhibited a reduction in gonadosomatic index (GSI) and changes in follicle maturation, while in males, only the number of cells in the testis was reduced. The authors have no interests to disclose.

The optokinetic response (OKR) is a reflexive behavior in which the eye intends to fixate the surrounding image in motion on its retina. The two important components of the OKR visual stimulus are the spatial frequency (SF) and the temporal frequency (TF). Zebrafish (Danio rerio) is considered an important model animal for visual physiology research. As a result, several works have been performed recently on zebrafish OKR in terms of their visual acuity or eye velocity. In the present study, a novel data pattern has been reported in terms of the relationship between ocular movement frequency (OMF) and TF of the visual stimulus in the presence of two types of SF of the optokinetic visual stimulus. The results indicated that at the basal SF (0.05 cycles per degree [cpd]), the OMF significantly increased (p < 0.05) with the corresponding elevation in the TF (till 240 deg.s^-1). On the contrary, at a higher SF (0.29 cpd), there was a significant decrease (p < 0.05) in the OMF with the increase in TF.

The transcription factor oligodendrocyte transcription factor 2 (Olig2) plays a central role in specifying motor neurons and oligodendrocytes during vertebrate neural development. While transgenic reporter lines such as TgBAC(olig2:EGFP) have been instrumental in visualizing olig2 expression, they fall short in directly reporting endogenous protein levels and may not fully recapitulate native gene regulation. To address these limitations, we generated a TgKI(olig2-mNeonGreen) zebrafish line using CRISPR/Cas9-mediated knock-in at the endogenous olig2 locus. The resulting Olig2-mNeonGreen fusion protein localizes specifically to the nucleus, enabling direct live imaging and accurate quantification of Olig2-expressing cells. We confirmed that the knock-in preserves endogenous mRNA expression and protein function, and that homozygous fish develop normally. As proof of concept, modulation of Sonic Hedgehog signaling altered Olig2-mNeonGreen+ cell numbers as expected, confirming the reporter's responsiveness to known upstream inputs. This TgKI(olig2-mNeonGreen) line offers a robust tool for studying neural progenitor dynamics in vivo.