When a certain gene is turned off in mice, it damages the stem cells that give hair its color—but not the regular color-making cells—so the hair gradually loses pigment and turns gray or white.

Even when scientists reduce a specific gene called DGUOK in mouse skin cells that make pigment, the cells still produce the same or even more melanin — so this gene doesn’t seem to stop pigment production.

When a specific gene needed for energy production in hair color cells is turned off in mice, the cells that give hair its color die off, causing the fur to turn gray over time.

Mice without a certain gene have more harmful molecules in their hair color stem cells when their hair is growing, which might be why these cells get damaged.

In mice with a specific genetic problem, hair turns gray because the stem cells that make hair color die off first—not because the color-making process itself is broken.

When a certain gene is turned off in hair color cells in mice, their fur starts to gray early because the cells die off — but the ones that survive can still make pigment just fine.