Like many natural patterns, feathers look elegant and simple, but zoom in on the molecules inside and a crowd of proteins is working to shape each individual branch. The healthy pattern of these chicken feathers (shown top middle and sketched below) is shaped by small GTPases – proteins that control how and when branches develop at different points on the feather’s rachis (central shaft). Removing two of these proteins, RhoA (left) or Cdc42 (right) alters the pattern. Some of the steps involved in tissue patterning, or morphogenesis, are common to other organs and even different species. Feather branching is used as a model for testing chemotherapies – watching how the delicate patterns cope with these powerful chemicals as a step towards helping human tissues recover after necessary, yet damaging cancer treatments.
Written by John Ankers
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