TY - JOUR TI - Unusual pattern of Sonic hedgehog expression in the polydactylous mouse mutant Hemimelic extra-toes. AU - Blanc, Isabelle AU - Bach, Antoine AU - Robert, BenoƮt T2 - The International Journal of Developmental Biology AB - We have examined the dynamic expression of Sonic hedgehog (Shh) in limb buds of the Hemimelic extra-toes (Hx) mutant. An ectopic domain of expression appears in the limb bud at embryonic day 11.5, which is not restricted to the anterior mesenchyme as in other polydactylous mutants, but extends along the entire apical ectodermal ridge. No difference in expression was observed between heterozygotes and homozygotes. This ectopic expression domain forms later and is maintained longer than the normal one. We verified that the Shh signal is properly transduced in the ectopic expression domain by analysing the expression of downstream target genes and provide evidence that the ectopic domain is functional. Interactions between Msx1 and Hx were investigated by constructing a double mutant strain. Embryos from this strain exhibit little difference in Shh expression compared to Hx simple mutants. However, homozygous Msx1/Hx double mutants exhibit a postaxial polydactyly at birth, demonstrating that the two genes interact. PY - 2002 VL - 46 IS - 7 SP - 969 EP - 974 J2 - Int. J. Dev. Biol. LA - en SN - 0214-6282 SN - 1696-3547 UR - https://ijdb.ehu.eus/article/12455636 Y2 - 2024/12/22/06:19:02 ER -