Who bred a rat? - briefly
«Who bred a rat?». The rat was produced by a laboratory researcher conducting genetic studies.
Who bred a rat? - in detail
The inquiry «Who bred a rat?» concerns the origin of the first systematic laboratory rat strain. The initiative began at the University of Pennsylvania in 1906 under the direction of H. H. Wistar. Wistar, a physiologist, selected a pair of wild‑caught Norway rats and, through successive generations of controlled mating, established a genetically homogeneous colony. This colony, later known as the Wistar rat, served as a standardized model for biomedical research.
Key aspects of the breeding program include:
- Initial capture of wild specimens to ensure genetic diversity before inbreeding.
- Implementation of a closed breeding system to prevent genetic contamination.
- Documentation of phenotypic traits such as coat color, size, and reproductive performance.
- Distribution of the strain to other institutions, facilitating reproducibility across experiments.
Subsequent contributors expanded the repertoire of laboratory rats:
- Harlan Laboratories introduced the Long‑Evans strain in the 1920s, emphasizing a pigmented coat and robust growth.
- The Sprague‑Dawley line, developed by L. Sprague and D. Dawley at the Sprague‑Dawley Company, emphasized high fecundity and rapid maturation.
- The Fischer 344 inbred strain, created by Hermann Fischer in the 1930s, provided a model for aging and tumor studies.
Collectively, these breeding efforts established the rat as a cornerstone of experimental biology, enabling controlled investigations in physiology, toxicology, genetics, and pharmacology.