BEIJING -- An international research team has for the first time identified nine genes responsible for eyebrow colors, according to a new report published in the Journal of Investigative Dermatology.

Eyebrow color is one of the most recognizable visual traits of the human body. It has a strong correlation with hair color, but scientists believe in the existence of overlapping and unique genetic components for both traits.

Previous studies on human eyes, hair, and skin color have identified multiple gene variants, but no findings for eyebrow color have been reported as of yet.

Eyebrow color shows a high degree of variation in Europeans. Moreover, hair color and eyebrow color are not exactly the same. Many people with brown hair have black eyebrows.

Using the method of genome-wide association study, researchers from China, the Netherlands, Australia, Britain and the United States analyzed samples of 6,513 European individuals, and graded colors into four categories: red, blond, brown and black.

They found that eight genes were previously known pigmentation genes and could affect both eyebrow and hair color, such as gene variant MC1R, responsible for both blond eyebrows and red hair.

In addition, C10orf11 is the newly identified gene that only affects eyebrow colors.

With these findings, researchers developed an eyebrow color prediction model and are ready to improve it by studying the different age distributions.

Liu Fan, lead author of the article and researcher at the Beijing Institute of Genomics of the Chinese Academy of Sciences, said such a DNA-based eyebrow color prediction model would improve the human phenotype research and be useful in future forensic applications.

"Based on the new discoveries, we can more accurately infer individual hair, eyes, skin, eyebrow color and other phenotypic information just from a DNA sample," Liu said.