Laboratory rat

The laboratory rat (Rattus norvegicus) is a model organism studied in biology laboratories.

Classification of the laboratory rat

The laboratory rat is an eukaryotic mammal in the Rodentia order and Muridae family.

Characteristics of the laboratory rat

The laboratory rat is a mammal 25 centimetres long weighing about 350 grammes. It has a pointed snout and a tail that is slightly shorter than its body. In its natural habitat, the brown rat is an omnivore and opportunistic rodent, also called the "sewer rat".

It has a linear double-stranded DNA genome, of 2.5 billion basic pairs divided into 21 chromosomes. It breeds quickly since it reaches sexual maturity after about forty days. Gestation lasts about three weeks. A female can then give birth to 60 young per year, or 1,000 descendants in just one year.

Use of the laboratory rat

There are many stocks or lines of Rattus norvegicus, with different characteristics and different types of coats. They are used as models for different diseases (cancer, diabetes...). After the mouse, the rat is the most commonly used mammal in experimentation.