What Makes Laboratory Rats Ideal for Research?
"Almost all human genes known to be associated with diseases have counterparts in the rat genome," according to the National Institutes of Health. Larger in size than mice, and with a short reproductive cycle and low breeding cost, laboratory rats are valuable to researchers in various therapeutic areas such as toxicology, immunology, teratology, experimental oncology, experimental gerontology, and cardiovascular research. Lab rats are particularly well suited to behavioral and psychological studies involving learning and cognition because of their ability to learn tasks quickly.
Genetically engineered rat models have been developed for understanding the pathophysiology of diseases. With the aid of these animal models, researchers are able to validate targets and identify pharmacological responses. Already, several rat genes tied to complex diseases have been identified.
The results of these studies have been translated to humans, leading to the discovery of novel human disease susceptibility genes, and helping to identify irregularities in humans and establishing treatment approaches.
Rat Models
- All Laboratory Rat Models
-
Inbred Rat Models
Inbred rats are created by mating at least 20 generations of brother/sister or parent/offspring combinations, with the goal of achieving homozygosity. Mating continues until offspring are genetically identical to their parents and each individual organism can be treated as a clone.
-
Outbred Rat Models
Outbred rat models are genetically diverse. Since humans have genetic variability, these models are useful for predicting how genetic variances are linked to diseases.
-
Hybrid Rat Models
Hybrid rats are the product of dissimilar parents. Genetic variabilities give hybrid strains longer lifespans and greater resistance to illness than their parents.
-
Immunodeficient Rat Models
Immunodeficient rat models lack immune cells such as NK, T, and B cell. These laboratory rats are used by researchers to study tumor growth rates and the responses of antitumor immunotherapies.
- Cryopreserved Rats
Guidebook to Rodent Model Genetic Quality Control
Learn the essentials of genetic QC programs: inbred/outbred colony quality control, transgenic rodent model creation, rederivation, and cryopreservation techniques.
Download Now
Genetic Engineering and Laboratory Rats
Mice have traditionally been considered choice research models because their embryonic stem cells are more robust than those of rats. But advances in genetic editing tools such as CRISPR-Cas9* and the use of engineered endonucleases make it possible to precisely target the rat genome. For example, by inactivating rat genes of interest with these tools, researchers are opening promising new pathways toward the study of infectious, cardiovascular, neurological, and other diseases.
Advancing Preclinical Research with the Rat Model
This presentation will explore how the unique physiological characteristics of rats provide translational value across multiple therapeutic areas, as well as best practices for husbandry that optimize both welfare and experimental reproducibility.
Watch the Webinar
Frequently Asked Questions About Laboratory Rats
-
How do rats compare with mice as animal research models?
Rats have a higher intellectual capacity than mice and morphological, physiological, and genetic similarities to humans. Laboratory rats are often considered better candidates than mice for behavioral studies and research on disorders involving learning and cognition because they are more capable of learnings tasks than mice. And since rats are larger in size than mice, handling and sampling are easier than with mice.
-
Why are rats well-suited for laboratory research?
The rat genome is comparable to the human genome, which makes rats desirable models for the study of diseases that affect humans. Rats and humans have similar nervous systems; we regulate hormones in similar fashion, and we have immune systems that respond to infection in comparable ways.
-
Which was the first standardized laboratory rat model?
The Wistar rat is the model from which more than half of all laboratory rat strains trace their lineage.
-
Is it possible to introduce genetic defects in laboratory rats to study human diseases?
Yes. Laboratory rat models can be produced by expressing the mutant human gene for a common genetic cause of human disease. For example, the Wistar rat has been modified to mimic a genetic defect specific to Parkinson’s disease.
-
Can any laboratory rat models be humanized?
Yes. We offer a humanizable model, the SRG rat. In a recent study, researchers were able to transplant full-thickness human skin and autologous lymphoid tissue into SRG rats and demonstrate humanized lymphoid tissue in the transplant-bearing rats
Development of Humanized Mouse and Rat Models with Full-thickness Human Skin and Autologous Immune Cells
Agarwal, Y., Beatty, C., Ho, S. et alSci Rep 10, 14598 (2020)
The SRG Rat: An Emerging Model in the Research Model Rat Race
Eureka Blog (2022)
-
What are the origins of the use of rats in scientific research?
In 1828, long before the standardization of the current laboratory rat, albino rats were used in a fasting study. Decades later, through inbreeding, the Wistar Institute created the Wistar rat. It became the first model to be used in medical and biological research. See The Early History of the Lab Rat.
*CRISPR-Cas9 is used under licenses to granted and pending US and international patents from The Broad Institute and ERS Genomics Limited.
