Distribution of Sonic hedgehog peptides in the developing chick and mouse embryo.

摘要: Sonic hedgehog (Shh) encodes a signal that is implicated in both short- and long-range interactions pattern the vertebrate central nervous system (CNS), somite limb. Studies vitro indicate Shh protein undergoes an internal cleavage to generate two secreted peptides. We have investigated distribution of peptides with respect these patterning events using peptide-specific antibodies. Immunostaining chick mouse embryos indicates are expressed notochord, floor plate posterior mesenchyme limb at appropriate times for their postulated functions. The amino peptide intercellular signaling but remains tightly associated expressing cells. ventral CNS polarized highest levels accumulating towards luminal surface. Interestingly, expression extends beyond plate, into ventrolateral regions from which some motor neuron precursors emerging. In bud, restricted small region posterior-distal close association apical ectodermal ridge; 50–75 microns along anterior-posterior axis. Temporal consistent induction sclerotome somites neurons CNS, as well regulation polarity However, we can find no direct evidence diffusion 19 × 10(3) Mr thought mediate cell interactions. Thus, either mediated indirectly by activation other signals, or alternatively low diffusing undetectable available techniques.