Why Xenopus laevis ?
Xenopus (anurans) are popular for use in research for a variety of reasons. Anurans are most commonly used ￼for anatomy, developmental biology, hormone studies cellular and molecular biology and electrophysiology. The external fertilization and development of their eggs make them a prime candidate for studies involving biological and mechanical manipulations. These frogs are very easy to maintain and can be induced up to two times a year to lay eggs with just a simple injection of hormone. They have very large eggs and the embryos develop quite quickly so microinjections, extracts and developmental analysis are all quite easy.
It is fundamental to be sure about the quality of the production of animals to obtain pertinent scientific informations. It is why strict rules are observed in our Xenopus facilities in CBD.
Xenopus housing is located at the ground floor of CBD in one ￼room of about 35 meter square maintained at 18°C by air conditioning. 600 frogs are kept in 47 clear, polycarbonate tanks containing each 40 l of carbon-filtered water. Frogs are maintained in a continuous flow of fresh water. The advantage of this is that toxic ammonia is kept low and prevents diseases. All the individual tanks are isolated from one another, keeping the colony free from potential cross contamination. Frogs are segregated by sex. A 12/12 light/dark cycle is maintained in the room.
Adult Xenopus laevis are carnivorous and eat submerged in water. Adults must receive 2-3 times each week a commercial trout pelleted diet ("soft-moist" trout diet). After feeding, tanks are cleaned and the water totally changed (three times a week).
X. laevis may be susceptible to disease in conditions of stress or when tank water are infected with Aeromonas and Pseudomonas bacteria (the cause of Red-Leg) or any gram negative or gram positive bacteria. Koizyme eliminates them by competitive exclusion and keep the Aeromonas, Pseudomonas and other pathogens at a very low level. To prevent bacteria over-proliferation Koizyme is added weekly in each tank.
However our sanitary conditions are so strict that we have only very rare infections on isolated animals.
Our Xenopus facilities include a Xenopus husbandry. This is not frequent in Xenopus facilities. We have the complete control of our crossbreeding and of the quality of produced animal.
Use of Xenopus
The animals are mainly used for experiment performed in developmental biology in M. Moreau’s team. However we furnish and accommodate animals for other groups on the campus external to CBD.
Teaching in developmental biology
Xenopus eggs and embryos are used for practical work.
- Electrophysiology and molecular biology (CRCA UMR 5169)
Xenopus oocytes are good recipient to express heterologous proteins in order to analyze their function
- Cellular biology (UMR5089, IPBS)
Oocytes are used to obtain cycling extract for the study of microtubules polymerisation.
- Ecotoxicology and genotoxicity (UMR5245, EcoLab)
Xenopus laevis larvae are used to evaluate the ecotoxicological potential of diverse industrial pollutants.-