muscle diseases, including muscular dystrophy.In Australia alone, investigators are also using zebrafish to study metabolic disorders such as: The future of zebrafishĬancer research is just one part of the zebrafish story. These processes, once properly understood, are likely to provide opportunities for therapeutic intervention in the future. Ben Hogan/Ludo Le Guen, Institute for Molecular Bioscience, University of Queensland Tumour growthĪs well as the transgenic zebrafish models of cancer described above, researchers are also transplanting cells derived from human tumours into zebrafish embryos and watching them grow and spread.īlood vessels and lymphatic system in a 9-day-old zebrafish larva. Human cord blood samples are a valuable commodity to restore bone marrow in leukaemia patients after high dose chemotherapy when a matched bone marrow transplant is unavailable.īut the success of this approach is currently limited by the scant number of stem cells in individual cord blood samples, requiring the use of two precious samples for each patient. Studies of dmPGE2 increased the number of blood stem cells in zebrafish embryos and it is being trialled now as a way to expand the number of stem cells in human cord blood samples. There, the intent is not to kill cancer cells but rather to make mainstream leukaemia treatment more effective. The only other drug from a zebrafish chemical screen currently in clinical trials is dimethyl-prostaglandin E2 ( dmPGE2).
One drug, Leflunomide, identified in such a screen is now in early phase clinical trials to kill melanoma cells. Large collections of drugs can be screened relatively quickly for anti-cancer efficacy in this way. Then, as the tumours grow in the synchronously developing larvae, the fish are transferred to small volumes of water containing chemicals that may stop the growth, or better still, kill the cancer cells. Here, the ability to generate tens of thousands of zebrafish embryos harbouring the same disease-causing mutations is crucial. These parallels have encouraged researchers to exploit zebrafish in drug development - in particular for high throughput approaches such as chemical/small molecule screens.
#Zebra fish skin#
This process, known as transgenesis, is very straightforward in zebrafish and has allowed researchers to produce zebrafish models of liver, pancreatic, skeletal muscle, blood and skin cancers, to name but a few.Īnd when the genomic make-up of these zebrafish tumours is deciphered using the latest DNA sequencing technology, the patterns of mutations, or “gene signatures”, are found to overlap substantially with those in the corresponding human tumours. This is especially true for cancer research where the expression of cancer-causing genes ( oncogenes) can be directed to specific organs, virtually at will. When just one or two cells old, zebrafish embryos can be easily microinjected with mRNA or DNA corresponding to genes of interest undeterred, they then they go on to grow and reproduce, handing down the injected gene to the next generation.Ĭonfocal micrograph showing the connections of the visual system in a four-day-old zebrafish embryo. Again, the large, external embryos are a critical part of this success. This provides unparallelled opportunities for researchers to scrutinise the fine details of embryonic vertebrate development without first having to resort to invasive procedures or killing the mother.īut this advantage is enhanced by the fact zebrafish reproduce profusely (each pair can produce 200-300 fertilised eggs every week) an ideal attribute for genetic studies. Most famously, zebrafish embryos, unlike mouse embryos, develop outside the mother’s body and are transparent throughout the first few days of life. Several things captured Streisinger’s imagination. In just 24 hours, the zebrafish heart is beating and blood is circulating around the body.īut as a vertebrate model, could they be as useful as mice?
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