Cosmetics

Stabulation of zebrafish requires less space and is cheaper than mice because adult zebrafish are smaller and are housed in large groups – up to 70 animals per tank versus only five mice per cage. This is one of the reasons making zebrafish more affordable than mammal research models. In addition, zebrafish pairs produce hundreds of offspring larvae per mating, providing a huge sample size, when compared to rodents. Moreover, larva size is only 5 mm, allowing the use of multiwell plates for separating experimental samples. Finally, drugs are administered in the swimming water, requiring lower amounts of compounds and reducing enormously the time invested in injecting drugs into rodents. All these features allow testing several conditions (different drugs and concentrations) in parallel and, overall, shortening the experimental time and cost, if compared with equivalent assays in rodents.

Zebrafish larvae are among the most informative, straightforward, and better characterized experimental models. Their optical transparency and ex-utero development, combined with a growing battery of fluorescent tissue-specific transgenic lines, allow direct in vivo visualization of cells, tissues, organs, and embryonic development under different chemical and genetic perturbations to perform simultaneous drug safety and efficacy assays.

Zebrafish embryos represent an ideal model for the screening of large compound libraries and streamlining the drug development process. The small size and the high number of zebrafish progeny allow parallel and reproducible testing of several drugs and dosages in simple multiwell plates and make it ideal for high throughput assays. In addition, the large sample size provides strong statistical power.

Zebrafish and humans have a high genetic homology, as well as high physiological and functional conservation. More than 70% of human genes have a zebrafish orthologue gene. This percentage goes up to 82% when considering human disease-associated genes. In addition, zebrafish show sensitivity, specificity, and accuracy in line with mammalian models. These biological features have positioned the zebrafish as an ideal tool for the study of diseases, biological processes, and drug effects. Indeed, it allows us to assess with certainty the role of a gene in the context of disease and the possible toxicity or effects a compound could have when administered to humans.

The zebrafish model fulfills the purpose of reducing, refining, and replacing the use of experimental animal models. Most of our research is conducted with zebrafish larvae before 5 days post fertilization, meeting the standards set by the European Commission Directive of 2010. The zebrafish model represents a viable alternative that bridges the gap between in vitro and mammal models and can lead to a reduction of animals used in later research phases.