Zebrafish最新文献

Zebrafish larvae are used to model the pathogenesis of multiple bacteria. This transparent model offers the unique advantage of allowing quantification of fluorescent bacterial burdens (fluorescent pixel counts [FPC]) in vivo by facile microscopical methods, replacing enumeration of bacteria using time-intensive plating of lysates on bacteriological media. Accurate FPC measurements require laborious manual image processing to mark the outside borders of the animals so as to delineate the bacteria inside the animals from those in the culture medium that they are in. Here, we have developed an automated ImageJ/Fiji-based macro that accurately detects the outside borders of Mycobacterium marinum-infected larvae.

Intestinal permeability plays a crucial role in intestinal barrier function. Altered intestinal permeability is well documented in numerous chronic diseases and may serve as a risk factor for disease onset as well as a target for innovative therapeutic strategies. While reliable and sensitive approaches for studying intestinal permeability have been established in animal models, such as mice and zebrafish larvae, methods for investigating this in adult zebrafish remain a considerable challenge. The zebrafish has emerged as a valuable model for studying intestinal development, physiology, and disease. Moreover, zebrafish offer certain advantages over rodent models, such as the ability to evaluate the dynamic interactions of labeled markers in vivo and in real time. In this study, we present a comprehensive pipeline for assessing in vivo intestinal permeability in adult zebrafish using fluorescent-labeled dextran. Detailed protocols for fish handling, reagent preparation, optimization of reagent dosage and delivery routes, and quantification of fluorescent markers in extraintestinal sites are provided. Our findings suggest that zebrafish hold promise as an alternative model for in vivo investigations of intestinal permeability induced by genetic, pathophysiological, and/or pharmacological events.

Retinal markers with high quality and specificity are important for the observation of pathologic changes of retinal cells during retinal development, degeneration, and regeneration. The zpr-3 antibody is widely used to label rods in zebrafish, but the exact antigen is still unknown. In this study, we provided evidence to demonstrate that the antigen gene of zpr-3 is rho, which encodes the rod opsin, and the exact epitope of zpr-3 is the 320-354 region of Rho protein. More importantly, our immunofluorescence assays indicated that zpr-3 labels both the outer segments of rods and green cones on zebrafish retinal sections, probably due to the cross-reaction with the green-cone opsin. Our work is valuable for the scientific community to interpret the experimental data involving the zpr-3 antibody.

Hydrocephalus is a cerebrospinal fluid-related disease that usually manifests as abnormal dilation of the ventricles, with a triad of clinical findings including walking difficulty, reduced attention span, and urinary frequency or incontinence. The onset of congenital hydrocephalus is closely related to mutations in genes that regulate brain development. Currently, our understanding of the mechanisms of congenital hydrocephalus remains limited, and the prognosis of existing treatments is unsatisfactory. Additionally, there are no suitable or dedicated model organisms for congenital hydrocephalus. Therefore, it is significant to determine the mechanism and develop special animal models of congenital hydrocephalus. Recently, zebrafish have emerged as a popular model organism in many fields, including developmental biology, genetics, and toxicology. Its genome shares high similarity with that of humans, and it has fast and low-cost reproduction. These advantages make it suitable for studying the pathogenesis and therapeutic approaches for various diseases, specifically congenital diseases. This study explored the possibility of using zebrafish as a model organism for congenital hydrocephalus. This review describes the characteristics of zebrafish and discusses specific congenital hydrocephalus models. The advantages and limitations of using zebrafish for hydrocephalus research are highlighted, and insights for further model development are provided.

The 2024 Zebrafish Husbandry Workshop and Summit held during the World Aquaculture Society Meeting in San Antonio focused on key areas for improving zebrafish husbandry research. Discussions highlighted the need for comprehensive literature on husbandry, better communication and collaboration between researchers and facility staff, and the adoption of a standardized reference diet. Current literature lacks comprehensive data and often overlooks crucial factors such as housing density and space requirements for fish development. Collaborative efforts between researchers and facility managers are essential for acquiring accurate husbandry data and minimizing pathogen risks. Standardizing descriptive language and parameter lists in publications and enhancing communication between facilities can improve research quality. Action items proposed include better communication of incoming fish information, standardization of pathogen monitors, transparency in husbandry practices, and fostering a spirit of collaboration among organizations. The summit emphasized the importance of increased PI awareness about husbandry, testing existing standardized diets, forming consortia to oversee diet standardization, creating unified repositories and forums, and conducting evidence-based husbandry studies.

Animal models are an important tool for studying noncommunicable diseases (NCDs) as they provide a unique opportunity to investigate real-time changes that occur in the onset of, and during, the diseased state. This is of particular importance given that the global prevalence of NCDs, such as type 2 diabetes mellitus (T2DM), is rising at an alarming rate. In South Africa, which has one of the highest levels of HIV in the world, the incidence of T2DM is thought to be associated, in part, with exposure to combination antiretrovirals. We report on the establishment of both nonobese and obese zebrafish models of T2DM, as well as associated changes in mRNA expression of preproinsulin and phosphoenolpyruvate carboxykinase (pck) 1 and 2. The diabetic state was achieved by either immersing adult zebrafish in a 2% glucose solution for 40 days or by overfeeding adult zebrafish for 10 weeks. Glucose immersion resulted in significantly elevated fasting blood glucose levels twice as high as control, whereas bodyweight did not change significantly (nonobese model). Overfeeding led to both significantly elevated fasting blood glucose and bodyweight compared with control (obese model). Both models were characterized by significantly increased preproinsulin mRNA expression indicating insulin resistance; mRNA expression of metabolic enzymes PCK 1 and 2 was also significantly upregulated, as seen in diabetic patients. These candidate gene expression changes, similar in both zebrafish models, establish a baseline that can be utilized to investigate the underlying mechanisms driving the increased T2DM incidence, using an excellent alternative to traditional rodent models.

Increasing carbon dioxide levels associated with climate change will likely have a devastating effect on aquatic ecosystems. Aquatic environments sequester carbon dioxide, resulting in acidic conditions that can negatively affect fish development. Increasing climate change impacts in the coming decades will have an outsized effect on younger generations. Therefore, our research had two interconnected goals: 1) understand how aquatic acidification affects the development of zebrafish, and 2) support a high school scientist's ability to address environmental questions of increasing importance to her generation. Working with teachers and other mentors, the first author designed and conducted the research, first in her high school, then in a university research laboratory. Zebrafish embryos were reared in varying pH conditions (6.7-8.2) for up to 7 days. We assessed fish length and development of the inner ear, including the otoliths; structures that depend on calcium carbonate for proper development. Although pH did not affect fish length, fish reared in pH 7.75 had smaller anterior otoliths, showing that pH can impact zebrafish ear development. Furthermore, we demonstrate how zebrafish may be used for high school students to pursue open-ended questions using different levels of available resources.

Xenotransplantation of neuroblastoma cells into larval zebrafish allows the characterization of their in vivo tumorigenic abilities and high-throughput treatment screening. This established preclinical model traditionally relies on microinjection into the yolk or perivitelline space, leaving the engraftment ability of cells at the hindbrain ventricle (HBV) and pericardial space (PCS), sites valuable for evaluating metastasis, angiogenesis, and the brain microenvironment, unknown. To address this gap in knowledge, Casper zebrafish at 48 h postfertilization were microinjected with approximately 200 Kelly, Be(2)-C, SK-N-AS, or SY5Y cells into either the HBV or PCS. Fish were imaged at 1, 3, and 6 days postinjection and tumor growth was monitored at each timepoint. We hypothesized that engraftment ability and location preference would be cell line dependent. Kelly and SK-N-AS cells were able to engraft at both the HBV and PCS, with a near doubling in size of tumor volume during the 6 days observation period, with cells appearing to grow better in the HBV. Be(2)-C tumors remained static while SY5Y tumors decreased in size, with almost complete loss of volume at both sites. Therefore, the capability of neuroblastoma cell engraftment in zebrafish larvae is cell line dependent with a location preference.

Soybean meal (SBM) has become a common dietary replacement for fish meal (FM) in aquafeed. However, at high inclusions, SBM has been shown to have negative impacts presenting as reduced feed intake and intestinal inflammation. Medicinal plant extracts, namely essential oils, have been used to promote growth performance and immune response. The objective of this study was to investigate the potential therapeutic effects of oregano (Origanum vulgare) essential oil (OEO) inclusion on utilization of a high-inclusion SBM diet using zebrafish as a model. Five diets were used in this study: reference-FM-based diet, control-55.7% inclusion SBM diet, and three experimental SBM-based diets OEO1, OEO2, and OEO3 that were supplemented with 1%, 2%, or 3% of oregano oil, respectively. The FM group had overall better growth performance when compared with the other treatment groups; however, the OEO3 mean weight and feed conversion ratio were not significantly different from the FM group (p > 0.05) and were significantly improved compared with the SBM group (p < 0.05). Similarly, OEO2 total length was not significantly different from FM (p > 0.05) but significantly higher than the SBM group (p < 0.05). Expression of inflammation-related genes did not significantly differ between the OEO groups and the SBM-only group. However, the OEO2 and OEO3 groups displayed improved growth performance compared with the SBM group, suggesting that inclusion of OEO at or above 2% inclusion may help to alleviate common symptoms induced by a high-inclusion SBM diet.