In a recent breakthrough, scientists have discovered 135 new genes related to skin color and pigmentation. These genes significantly determine skin color, hair, and eyes by producing a pigment called melanin. This exciting discovery enhances the complex factors influencing human appearance. It opens new avenues for studying skin-related conditions.
The color of our skin, hair, and eyes is determined by a pigment called melanin. A recent article in the journal Science talks about a study led by Dr. Vivek Bajpai and his team at the University of Oklahoma, along with collaborators from Stanford University. They found 135 new genes connected to this pigment.
Melanin is made in special parts of cells called melanosomes. These are found inside cells called melanocytes. Even though everyone has the same number of melanocytes, they produce different amounts of melanin, leading to various skin colors.
To figure out why some cells make more melanin, the researchers used a technology called CRISPR-Cas9 to change cell genes. They tested over 20,000 genes in millions of melanocytes to see their effect on melanin.
The genes that influenced melanin production needed to be singled out from other cells. Dr. Bajpai created a new method for this in the lab. He shone light through the melanocytes and checked if the melanin absorbed or scattered the light. It helped them figure out which genes played a role in making melanin.
Bajpai said, “If there are a lot of melanin-producing melanosomes, the light will scatter much more than in cells with little melanin. Using a process called side-scatter of flow cytometry, we could separate cells with more or less melanin. These separated cells were then analyzed to determine the identity of melanin-modifying genes. We identified new and previously known genes that play important roles in regulating human melanin production.”
The scientists found 169 genes that influenced the production of melanin, the pigment that gives color to our skin, hair, and eyes. Among these genes, 135 were newly discovered and hadn’t been linked to pigmentation before. They also learned about two new genes, KLF6 and COMMD3. One of these genes, KLF6, affected melanin in humans and animals, showing its importance across species. The other gene, COMMD3, controlled how much melanin was made by managing the acidity of certain cell parts.
To understand this, they used a process where they shone light to see which parts were making melanin. Throughout history, people living in places with strong sunlight needed more melanin to protect them from the sun’s harmful rays. But humans needed less melanin as they moved to areas with less sun.
This discovery has potential benefits. Understanding melanin can help protect people with lighter skin from skin cancer. Scientists might even create medicines to adjust melanin for conditions like vitiligo. The methods they developed could also help find genes that control melanin in fungi and bacteria, which can cause diseases in humans and crops. It could lead to better ways to fight these harmful microbes.
Dr. Bajpai worked on this study at the University of Oklahoma and during his time at Stanford University. The research got support from various sources, including grants and funding from different organizations.
Journal Reference:
- Vivek K. Bajpai et al., A genome-wide genetic screen uncovers determinants of human pigmentation. Science. DOI: 10.1126/Science.ade6289.