“…More specifically, Fgf3 and Fgf8 have pronounced expression in the pharyngeal endoderm and ectoderm, and embryos injected with antisense morpholinos directed against the transcripts of these two genes fail to form pharyngeal cartilages (David et al, 2002;Walshe and Mason, 2003). Other studies have also noted that the mature pharyngeal arches are a prominent site of expression of members of the FGF synexpression group, including the transcriptional effectors pea3 and erm, as well as inhibitors of FGF signaling, such as Pyst1 (MKP3) and sprouty 2 (Munchberg et al, 1999;Chambers and Mason, 2000;Chotteau-Lelievre et al, 2001;Eblaghie et al, 2003;Walshe and Mason, 2003).…”