Mouse Facility

Mice as model organism

Mice are an important animal model at the FLI. Among other things, they are used to study the decline in stem cell function and age-related diseases such as muscle wasting and colon cancer.

Mice bred as laboratory animals differ significantly from their relatives in the wild. While wild mice are generally smaller and brown-gray in color, laboratory mice come in a variety of colors and sizes. Due to decades of breeding under laboratory conditions, their behavior is calmer and less aggressive than that of wild mice.

So-called inbred strains are often used in research. These are created when only siblings are mated with each other over several generations (at least 20). Animals from such strains are genetically largely identical and particularly valuable for research because they allow for comparability. Since the development of genetic engineering methods, individual genes in mice can be specifically modified and examined for their particular function. The scientific results of such investigations are not influenced by genetic variability.

The FLI maintains various mouse strains that carry one or more genetic modifications. The genes being researched here play an important role in mechanisms such as nerve regeneration and DNA damage.

Optimal housing conditions

To ensure optimal housing conditions for the animals, numerous measures are taken:

• Group living: The mice live together in small groups. Young animals are separated from their parents at three to four weeks of age.
• Cages: All cages have their own air supply and extraction system. The air is cleaned, filtered, and humidified. The temperature is maintained at 21-22 degrees Celsius, and the humidity is between 40 and 60 percent. The cages are equipped with devices such as play tunnels and nesting materials.
• Nutrition: The mice have unrestricted access to food and water. The food is optimally tailored to the needs of the rodents and is sterilized before consumption.

Animal Caretaker

The typical tasks of animal caretakers include daily inspection of the mice, changing the water bottles and cages, and feeding the animals.

During the weekly cage change, the mice are placed in autoclaved (steam-sterilized) cages with fresh bedding and nesting material. In addition, the health status of the mice is thoroughly checked each time the cages are changed.

An independent laboratory checks the hygiene status of the mouse facility on a quarterly basis. In all work, compliance with high hygiene standards and careful documentation of all data are given the highest priority.

Animal caretakers are also involved in the breeding of various genetically modified mouse strains. They record newborn animals in an electronic database and evaluate each litter. Each mouse is given its own number and can be uniquely identified throughout its life by this number and a toe tattoo.

In addition, the animal caretakers support the scientists in conducting experiments.

With their careful work, they make an indispensable contribution to aging research at the FLI.

Services of mouse husbandry

As a service for scientists, the mouse facility offers, among other things, the sanitation of mouse strains. Mouse strains differ in terms of common characteristics that have arisen through breeding or genetic modifications. “Sanitation” refers to the extraction of embryos from contaminated animals of a mouse strain. These embryos are implanted into pseudopregnant females that are kept in a pathogen-free area. This improves the hygiene status of a mouse strain, leading to more comparable and therefore more meaningful research results.

Other services include cryopreservation, i.e., the freezing of mouse sperm or embryos for the long-term preservation of individual mouse strains. This makes it possible to preserve strains for many years without continuous breeding and to reactivate them for research purposes when needed. By shipping frozen sperm or embryos to cooperation partners, the transport of live animals can also be avoided.

Animal caretaker vocational training

To ensure that our animals are in good hands, the FLI offers its own vocational training program for animal caretakers in research and clinical settings.

You can find more information about vocational training at the FLI here (LINK).