LEFT AND RIGHT: A wild type st 45 Xenopus embryo with rightward heart looping and counter-clockwise gut coiling is shown on the left. In contrast, a st 45 embryo that was injected with Pitx2 at the 4 cell stage exhibits leftward heart looping and clockwise gut coiling.
Earlier research had identified growth factors contributing to handedness, including sonic hedgehog ( Shh ) in chicks (M. Levin et al., Cell, 82:803-14, 1995) and nodal in mouse (J. Heymer et al., Mechanical Development, 66:5-11, 1997). But...
Interested in reading more?
Become a Member of
Receive full access to digital editions of The Scientist, as well as TS Digest, feature stories, more than 35 years of archives, and much more!