Glowing sugars light up zebrafish

Fluorescently labeled sugars light up to reveal cells in the skin layer of the jaw region of a three-day-old zebrafish embryo, seen from below with the nose at the top. More recently produced carbohydrates (red) are on the surface of cells, creating red rings, while carbohydrates produced earlier in development (green) have moved to the inside of cells, making green disks. Yellow areas are where old and new carbos congregate together. Credit: Bertozzi laboratory/UC Berkeley