House mouse in the context of Laboratory mice

A mouse (pl.: mice) is a small rodent. Characteristically, mice are known to have a pointed snout, small rounded ears, a body-length scaly tail, and a high breeding rate. The best known mouse species is the common house mouse (Mus musculus). Mice are also popular as pets. In some places, certain kinds of field mice are locally common. They are known to invade homes for food and shelter.

Mice are typically distinguished from rats by their size. Generally, when a muroid rodent is discovered, its common name includes the term mouse if it is smaller, or rat if it is larger. The common terms rat and mouse are not taxonomically specific. Typical mice are classified in the genus Mus, but the term mouse is not confined to members of Mus and can also apply to species from other genera such as the deer mouse (Peromyscus).

A genetically modified mouse, genetically engineered mouse model (GEMM) or transgenic mouse is a mouse (Mus musculus) that has had its genome altered through the use of genetic engineering techniques. Genetically modified mice are commonly used for research or as animal models of human diseases and are also used for research on genes. Together with patient-derived xenografts (PDXs), GEMMs are the most common in vivo models in cancer research. The two approaches are considered complementary and may be used to recapitulate different aspects of disease. GEMMs are also of great interest for drug development, as they facilitate target validation and the study of response, resistance, toxicity and pharmacodynamics.

Fear of mice and rats is one of the most common specific phobias. It is sometimes referred to as musophobia (from Greek μῦς "mouse") or murophobia (a coinage from the taxonomic adjective "murine" for the family Muridae that encompasses mice and rats, and also Latin mure "mouse/rat"), or as suriphobia, from French souris, "mouse".

The phobia, as an unreasonable and disproportionate fear, is distinct from reasonable concern about rats and mice contaminating food supplies, which may potentially be universal to all times, places, and cultures where stored grain attracts rodents, which then consume or contaminate the food supply.

Gerald Jinx Mouse, known simply as Jerry, is an American character and one of the two titular characters in Metro-Goldwyn-Mayer's series of Tom and Jerry theatrical animated short films and other animated media, usually acting as the protagonist opposite his rival Tom Cat. Created by William Hanna and Joseph Barbera, Jerry is an anthropomorphic (but usually silent) brown house mouse, who first appeared in the 1940 MGM animated short Puss Gets the Boot.

The character was not referred to by name in his debut cartoon; Hanna said that the mouse's original name as "Jinx", while Barbera claimed the mouse went unnamed in his first appearance. A 1940 article from MGM's Short Story magazine, however, would refer to the character as "Pee-Wee".

Actin filaments (also known as microfilaments) are protein filaments in the cytoplasm of eukaryotic cells that form part of the cytoskeleton. They are primarily composed of polymers of actin, but are modified by and interact with numerous other proteins in the cell. Actin filaments are usually about 7 nm in diameter and made up of two strands of actin. Microfilament functions include cytokinesis, amoeboid movement, cell motility, changes in cell shape, endocytosis and exocytosis, cell contractility, and mechanical stability. In inducing cell motility, one end of the actin filament elongates while the other end contracts, presumably by myosin II molecular motors. Additionally, they function as part of actomyosin-driven contractile molecular motors, wherein the thin filaments serve as tensile platforms for myosin's ATP-dependent pulling action in muscle contraction and pseudopod advancement. Microfilaments have a tough, flexible framework which helps the cell in movement.

Actin was first discovered in rabbit skeletal muscle in the mid 1940s by F.B. Straub. Almost 20 years later, H.E. Huxley demonstrated that actin is essential for muscle contraction. The mechanism in which actin creates long filaments was first described in the mid 1980s. Later studies showed that actin has an important role in cell shape, motility, and cytokinesis.