P6 An approach to the role of hedgehogs in vascular development via the chicken mutant talpid³

The polydactylous chicken mutant talpid³ has an abnormality in Hedgehog signalling. We have shown that this leads to the ectopic localisation of Shh protein in the limb and this has important consequences on limb patterning. Futhermore there is an abnormal vasculature pattern in the talpid³ embryos including that of the limb (Mohammed 1986). Through analysis of talpid³ we have examined the effects that abnormal hedgehog signalling has on the vasculature. We have further characterised the role of Shh in patterning the vasculature of the limb through manipulations of the normal wing bud. Recent evidence has shown that hedgehogs play an important role in the patterning of the vasculature of the zebrafish (Lawson et al. in press) and this is consistent with the abnormal patterning of the vasculature in the talpid³ limb.