The “M” marking on the foreheads of cats has inspired several legends across different cultures. One of the most popular ones involves a newborn Jesus Christ kept warm by a random cat. Mary later marked its forehead with her initials as a token of gratitude. On the other hand, in Islamic tradition, the Prophet Muhammad had a pet cat named Muezza who bowed to him in gratitude. The prophet petted the cat and bestowed upon it, and all cats, a special blessing.
Nevertheless, beyond these charming legends, the “M” marking characterizes cats with a classic tabby pattern and its different variations. It is also noticeable in several cats with either tricolor or solid or single-color coat patterns. Furthermore, aside from domestic cats, other felids, including the African wildcat and other small wild cats—essentially all felid species that possess the genes that control the tabby patterns—also have these remarkable markings on their foreheads.
Understanding the “M” Marking on the Foreheads of Cats: A Scientific Explanation
Tabby Coat Pattern
All tabby cats have the “M” marking on their foreheads. Note that the term “tabby” is not a breed but a descriptive word for a coat pattern common in domestic cats of various breeds. It also comes in variations like the classic, striped or mackerel, spotted, and ticked patterns. This iconic forehead marking is almost always present in grey-haired cats and orange or ginger cats.
There are specific genes that control coat patterns. The agouti gene is one of the essential genes in the expression of the tabby pattern. It controls the production of dark and light pigments and their distribution within individual hair strands via the agouti signaling protein. Hence, in cats with tabby coat patterns, this results in a hair strand with alternating bands of light and dark color.
It is worth mentioning that the agouti gene is also found in different mammals. This gene works with melanin receptors to regulate the color of melanin pigments. In cats, the dominant wild-type A allows hairs to be banded with dark and light melanin pigments to reveal the underlying tabby pattern, while the non-agouti genotype generally masks or hides the tabby pattern.
The Taqpep gene is another essential gene unique to cats. It determines if the coat will feature striped or blotched patterns. This gene is also found in cheetahs. Another notable gene is Dkk4. Research showed that it produces a pre-pattern of thick and thin skin on the developing cat embryo. This later ends up mapping the pattern of stripes in the fur of a growing cat.
Consistent Feature
The tabby coat pattern is an ancestral trait found in the wild feline ancestors of modern domestic cats. Previous studies of modern and ancient wild cats have suggested that it is a fundamental coat pattern that has been present in feline lineages for a very long time. Specifically, because cats are hunters and predators, the main evolutionary driver behind this pattern is camouflage.
Nevertheless, with regard to the iconic forehead marking, the “M” marking is not a separate trait because it is a consistent feature within the broader tabby coat pattern. The same agouti gene is responsible for producing alternating bands of light and dark fur shades in the foreheads of cats and other genes like the Dkk4 gene provide a pre-pattern for mapping this marking.
Some cats that do not appear to be classic tabbies, those with solid colors, and several calicos also feature a faint “M” marking on their foreheads. This is due to the influence of the same agouti gene that produces ghost markings. The genetic predisposition for the tabby pattern is often still present although masked since coat patterns and colors involve multiple gene interactions.
It is worth noting that the “M” marking is also visible even in hairless cat breeds like the Sphinx or Bambino as ridges or wrinkles in their foreheads. This suggests that this marking may also be influenced by musculature or the arrangement of muscles in the body of cats. Cats have intricate facial muscles that can affect the way the skin and fur lie on the foreheads and bodies.
FURTHER READINGS AND REFERENCES
- Eizirik, E., Yuhki, N., Johnson, W. E., Menotti-Raymond, M., Hannah, S. S., and O’Brien, S. J. 2003. “Molecular Genetics and Evolution of Melanism in the Cat Family.” In Current Biology. 13(5): 448-453. Elsevier BV. DOI: 1016/s0960-9822(03)00128-3
- Kaelin, C. B., McGowan, K. A., and Barsh, G. S. 2021. “Developmental Genetics of Color Pattern Establishment in Cats. In Nature Communications. 12(1). Springer Science and Business Media LLC. DOI: 1038/s41467-021-25348-2
- Kaelin, C. B., Xu, X., Hong, L. Z., David, V. A., McGowan, K. A., Schmidt-Küntzel, A., Roelke, M. E., Pino, J., Pontius, J., Cooper, G. M., Manuel, H., Swanson, W. F., Marker, L., Harper, C. K., van Dyk, A., Yue, B., Mullikin, J. C., Warren, W. C., Eizirik, E., … Menotti-Raymond, M. 2012. “Specifying and Sustaining Pigmentation Patterns in Domestic and Wild Cats.” In Science. 337(6101): 1536-1541. American Association for the Advancement of Science. DOI: 1126/science.1220893
- Lyons, L. A., Bailey, S. J., Baysac, K. C., Byrns, G., Erdman, C. A., Fretwell, N., Froenicke, L., Gazlay, K. W., Geary, L. A., Grahn, J. C., Grahn, R. A., Karere, G. M., Lipinski, M. J., Rah, H., Ruhe, M. T., and Bach, L. H. 2006. “The Tabby Cat Locus Maps to Feline Chromosome B1. In Animal Genetics. 37(4): 383-386. Wiley. DOI: 1111/j.1365-2052.2006.01458.x