With human retinas grown in a petri dish, researchers discover how humans generate the specialized cells that enable us to see millions of colors.
Using human retinas grown in a petri dish, researchers have discovered how an offshoot of vitamin A generates the specialized cells that enable people to see millions of colors, an ability that dogs, cats, and other mammals do not possess.
"These retinal organoids allowed us for the first time to study this very human-specific trait," said author Robert Johnston, an associate professor of biology at Johns Hopkins University. "It's a huge question about what makes us human, what makes us different."
The findings, published today in PLOS Biology, increase understanding of color blindness, age-related vision loss, and other diseases linked to photoreceptor cells. They also demonstrate how genes instruct the human retina to make specific color-sensing cells, a process scientists thought was controlled by thyroid hormones.
Read more at Johns Hopkins University
Image: Retinal organoid marked to show blue cones in cyan and green/red cones in green. Cells called rods that help the eye see in low-light or dark conditions are marked in magenta.(CREDIT:SARAH HADYNIAK/JOHNS HOPKINS UNIVERSITY)