What is a red‑colored mouse? - briefly
«A red-colored mouse is a laboratory mouse whose coat has been genetically modified or dyed to display a red hue, serving as a visual marker in biomedical research.» «The distinctive coloration enables easy identification of transgenic lines and tracking of experimental subjects.»
What is a red‑colored mouse? - in detail
A mouse with red pigmentation displays fur that ranges from bright scarlet to deep mahogany. The coloration originates from the presence of eumelanin and pheomelanin pigments, with an increased proportion of pheomelanin producing the reddish hue. Genetic mutations in the melanocortin‑1 receptor (MC1R) gene or in the agouti signaling protein (ASIP) can shift melanin synthesis toward pheomelanin, resulting in the observed coat color.
In laboratory settings, red‑colored specimens are often derived from specific strains such as C57BL/6J mice carrying the Ay allele, which induces a yellow‑to‑red coat. Breeding programs may select for this trait to study pigment‑related pathways, dermatological conditions, or to create visual markers for genetic experiments.
Key biological aspects include:
- Pigment biochemistry – Pheomelanin absorbs shorter wavelengths, reflecting a reddish appearance; its synthesis is regulated by tyrosinase activity and the balance of intracellular cyclic AMP.
- Genetic determinants – Mutations in Mc1r, Asip, and related loci alter the eumelanin/pheomelanin ratio; homozygous recessive alleles often produce a uniform red coat, while heterozygous combinations yield mixed patterns.
- Physiological implications – Elevated pheomelanin levels can influence susceptibility to oxidative stress, as pheomelanin generates reactive oxygen species under UV exposure.
- Behavioral observations – Studies report no consistent correlation between coat color and activity levels, anxiety, or learning performance; phenotypic differences are primarily cosmetic.
In wild populations, red fur is rare, typically appearing in isolated geographic variants where selective pressures favor camouflage among reddish substrates or vegetation. Such variants may arise through natural selection acting on the same pigment‑related genes identified in laboratory strains.
Commercially, red‑colored mice serve as ornamental pets. Breeders emphasize health screening to avoid linked hereditary issues, such as coat‑related skin disorders or auditory deficits that sometimes accompany pigment mutations.
Overall, the red hue results from a defined set of genetic and biochemical mechanisms, manifests across both laboratory and natural contexts, and provides a valuable model for investigating pigment biology, disease susceptibility, and genetic inheritance.