The Aquatic Zebrafish Core provides services using the small vertebrate zebrafish as a model for human disease and to study gene function.
There are numerous reasons to model a disease in a fish, including the rapid, five-day development of zebrafish and the ability to image whole organs in vivo and perform time-lapse analysis. Also, zebrafish models give us the ability to complete drug screens by simply adding your drug to 100uL of fish water, perform behavioral analysis, and make it easy to create knock-outs and transgenic lines.
The Zebrafish Core serves all researchers at Children’s Hospital of Philadelphia and the University of Pennsylvania as well as outside organizations. We aim to make the zebrafish model accessible to everyone – from clinicians without their own labs to principal investigators with well-established projects.
Four microinjection stations are available to inject freshly fertilized zebrafish eggs for Crispr/Cas9 knock-outs, transgenesis, and more.
The zebrafish facility is a 576-tank fish facility made by Aquaneering that offers sufficient space for several labs with the option for expansion to 1,080 tanks. The water system is equipped with a fluidized bed biofilter and is fully automated, providing stable water conditions. Additional features include an alarm system that minimizes accidental risk to the animals and incubators required to grow zebrafish larvae.
Zebrafish have a set of defined behavioral patterns that can be used for tests. The Zebrafish Core can monitor activity (e.g., speed, velocity, frequency) and response to specified stimuli.
You can use our expertise to model your disease of interest in zebrafish. The core can plan, design, and analyze a disease model for you. Typically, we create a gene knock out or knock-in, analyze the phenotype, and help to compare the results to a patient’s disease. As next steps we can analyze disease mechanisms in detail and start a drug screen to find reagents that can overcome a disease state.
The accessibility to gene knockouts and transgenes enables zebrafish to serve as a disease model so investigators can screen for drugs and the results can translate to the clinic. Fish can be grown in small groups in 6- to 96-well pates. Drugs can be added to the water and most are taken up through the skin, intestine, or thin gill epithelium. Due to the clarity and size of larvae, drug rescue is easily detectable.
Most agents can be injected in the first forming cell with a fine glass needle and are then passed along to the dividing cells. CRISPR/Cas9 knock-outs are efficient and the core can create a complete knock out of a locus in the injected generation for most genes. Transgenic expression and integration is also efficient due to special tools. Most zebrafish researchers use the gateway cloning system that relies on 3 fragments (e.g. promoter, gene, fluorescent tag) that is cloned in a transgenesis vector; the fragments are interchangeable and a large tool box of different promoters, genes, and labels is available.
Equipment and reagents to perform in situ mRNA hybridization, antibody staining, and other histological and functional staining is available, as well as a Microtome for 3uM thin sectioning of JB-4 plus embedded larvae.
Imaging is an essential part of zebrafish research. The larvae are clear and all organs are visible. The size of a 5-day-old larvae is ideal for microscopy; it is thin enough to focus through a whole larvae, and organs are small enough so an entire organ can be imaged with a confocal microscope and a 20x lens. Zebrafish researchers have created fluorescent lines labeling nearly all organs or specific tissues within organs. Time-lapse analysis is another hallmark of zebrafish research, allowing fish to be followed under a microscope for hours or days so observation of organ development, nerve growth, tissue interaction during tumor formation, or whole animal development in mutants is possible.
We train researchers to become zebrafish experts. We provide training in all fish-relevant techniques, help you to get a project started, and provide consultations during ongoing projects.