..., by utilizing maternal transfer of 5E1 (an anti-Shh antibody) to mouse embryos through the placenta, we show that Sostdc1 is downstream of Shh signaling and suggest a Wnt-Shh-Sostdc1 negative feedback loop as a pivotal mechanism controlling the spatial patterning of teeth. Furthermore, we propose a new reaction...

... the coupling of an extracellular gradient with a positive-feedback loop. In this mode of patterning, precision and robustness can be achieved by the introduction of a negative-feedback loop, which, in the hindbrain, is mediated by Spry4. * Author for correspondence ( [email protected]...

... and the embryo activates the expression of Hh target genes. One of these target genes, patched , forms a negative feedback loop with ci that is regulated by Hh signal transduction. Activation is also achieved using the Ci zinc finger domain fused to a heterologous transactivation domain. Conversely, repression...