has part has developmental contribution from has potential to develop into surface structure apical ectodermal ridge paired limb/fin bud limb - fin bud An outgrowth on the lateral trunk of the embryo that develops into a limb or paired fin. The limb/fin bud is divided into ectoderm and mesenchyme[cjm, modified from MP]. VHOG:0001258 Genes: In limb buds of chick and mouse, Shh expression is activated as soon as there is a morphological bud, whereas in S. canicula fin buds, consistent with reported data in other cartilaginous fishes, Shh is transcribed late in fin development[PMID:17187056] paired appendage bud paired limb/fin bud paired limb/fin paired limb/fin field presumptive structure