Boston, MA--March 8, 1999--The structural differences between an arm and a leg are crucial to their proper function: digits that flex and curl are needed in a hand for grasping while strong muscles in the legs allow for walking and running. Now researchers at Harvard Medical School have unveiled the molecular instructions that command these differences, and have identified a gene that can partially transform the upper limb of a vertebrate into a structure that resembles its lower limb. Their findings, published in the March 12 Science, open new doors to understanding how vertebrate limbs acquire their identity. Postdoctoral fellow Malcolm Logan and Clifford Tabin, professor of genetics at Harvard Medical School, took a gene that is normally only active in legs and transferred it to the forming wings of chick embryos. The resulting structures lost many of their wing characteristics and gained those of a leg: feathers were gone, claws appeared at the end on the digits, and leg-specific muscles were clearly identifiable.
The above story is based on materials provided by Harvard Medical School. Note: Materials may be edited for content and length.
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