The overall number of melanocytes is roughly equivalent for all people, however the level of melanin inside each melanosome and the number of melanosomes inside a melanocyte varies. Specialized cells known as melanocytes produce the melanin, storing it in intracellular compartments known as melanosomes. The color of human eyes, skin and hair is primarily controlled by the amount and type of a pigment called melanin. In a future edition, we’ll discuss genetic factors that contribute to skin and hair color. In this edition of Biotech Basics, we’ll explore the science behind pigmentation and discuss the genetics of eye color. Additionally, many of the genes involved in eye color also influence skin and hair tones. Unfortunately, this model is overly simplistic and incorrect – eye color is actually controlled by several genes. It’s one of the few genetic concepts that adults often recall from their high school or college biology classes. This would mean that two blue-eyed parents would always produce blue-eyed children, never ones with brown eyes.įor most of the past 100 years, this version of eye color genetics has been taught in classrooms around the world. They suggested that brown eye color is always dominant over blue eye color. In 1907, Charles and Gertrude Davenport developed a model for the genetics of eye color. This multifactorial model for eye color explains most of the genetic factors that influence eye color.

However, other genes can override the OCA2 instruction, albeit rarely. One gene, OCA2, controls nearly three-fourths of the blue-brown color spectrum.The genes control the amount of melanin inside specialized cells of the iris. Today, scientists have discovered that at least eight genes influence the final color of eyes.Eye color was traditionally described as a single gene trait, with brown eyes being dominant over blue eyes.DNA provides the set of recipes, or genes, used by cells to carry out daily functions and interact with the environment.Scientists now realize such a model is overly simplistic and incorrect.

Download the PDF version of Biotech Basics: Genetics of Eye ColorĬountless students have been taught that a single gene controls eye color, with the allele for brown eyes being dominant over blue.

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