Zebrafish Danio rerio is a freshwater fish native to Asia (India, Pakistan, Bangladesh, Nepal). It lives in stagnant water, slow-moving rivers and rice paddies. The zebrafish’s transparent embryos, which develop outside the mother, have made the zebrafish a powerful model to study the development of fish, and by extension, vertebrates. Today, the scientific community also uses zebrafish to gain a better understanding of the fundamental cellular mechanisms involved in the spread of some diseases, such as cancer.
In addition, its excellent reproductive capacity (abundant egg-laying all year round), and the low stringency of the rearing conditions make it easy to use.
The zebrafish is an oviparous species. Egg-laying is abundant and the breeding season is constant throughout the year. Adults may prey on eggs: to avoid it, putting logs or a grid at the bottom of the tank is commonly used. Once fertilized by the male, the eggs fall to the bottom of the tank, and can be harvested once adults are removed. Incubation lasts about 48 hours at 28°C. After fertilization, the egg will undergo a succession of synchronous divisions leading to a set of identical and totipotent cells. At the midblastula transition stage, zygotic genome is activated. Gastrulation will then start. Zebrafish development is very fast: only 24 hours after fertilization, the single-cell zygote turns into a tadpole embryo. An adult zebrafish measures 2 to 3 cm.
As its name suggests, zebrafish has five horizontal blue stripes along the body. It can be bred after three months for the earliest offspring.
[FR] Biologie du développement de Scott-F Gilbert et Susan-R Singer (Auteurs), Sylvie Rolin et Etienne Brachet (Traducteurs) Editions : De Boeck, 2e édition (13 mai 2004)
[FR] “Etablissement des axes embryonnaires au cours du développement du poisson zèbre”, Bernard Thisse et Christine Thisse, MEDECINE/SCIENCES 2002 ; 18 : 193-204