EXPERIMENTS ON LABORATORY SMALL ANIMALS

The remarkable significance of rat and mouse models in biomedical research has been demonstrated. In addition, other small domestic animals, both mammalian and non­mammalian, such as hamsters, rabbits, ferrets, guinea pigs, amphibians, fish, flies, and worms, are equally important in terms of their anatomical and physiological similarities to humans.

Approximately 95% of laboratory animals are mice and rats, with mice being the most often utilised animal in biomedical research. For a number of reasons, includ­ing their small size (which makes them easier to house and maintain), short lifespan and reproductive cycle, generally mild-mannered and docile nature, abundance of informa­tion about their anatomy, genetics, biology, and physiology, and the potential to breed genetically altered mice and mice with spontaneous mutations, mice are frequently used as animal models.

Mice have been employed as study animals in a variety of fields, including engineering, psychology, and biology. In an effort to discover remedies or cures, they are employed to simulate human illnesses. Hypertension, diabetes, cataracts, obesity, seizures, respiratory issues, deafness, Parkinson’s disease, Alzheimer’s disease, several malig­nancies, heart disease, muscular dystrophy, and spinal cord injuries are a few of the illnesses they simulate. In addition, mice are employed in research on behaviour, senses, age­ing, diet, and genetics. The domestic mouse is being used in study by biologists, geneticists, and other scientists at a rapid pace, therefore this list is by no means exhaustive.

A common choice for mammalian research models is the domestic mouse, Mus musculus and related subspecies, because to its small size, short lifespan, adaptability, docil­ity, inexpensive husbandry expenses, fertility, and clearly characterised health and genetic backgrounds. Genetic modification, such as “humanization” through the use of human genes, tumours, immune cells, or microbiome com­ponents, is also comparatively simple. The use of mice as study subjects has been greatly expanded and enhanced by the advent of embryonic genome editing techniques, most notably the CRISPR-Cas9 system and next-generation prime editing, in the production of GEM (genetically modi­fied model) mice. These developments have led to the devel­opment of innumerable mutant genotypes of mice, which range from minor immune function abnormalities to severe hereditary disorders that are almost exactly similar to those that affect humans and other mammals (Figure 26.6).

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