Sox18 expression in blood vessels and feather buds during chicken embryogenesis

Sox18 encodes a transcription factor known to be important for the developm ent of blood vessels and hair follicles in mice. In order to study the func tional conservation of this gene through evolution, we have isolated and ch aracterized Sox18 in chickens. cSox18 shows a high degree of sequence homol ogy to both the mouse and human orthologues, particularly in the high mobil ity group DNA-binding domain and to a lesser extent in the transcriptional activation domain. A region of unusually high sequence conservation at the C-terminus may represent a further, previously unrecognized functional doma in. Both the chicken and human proteins appear to be truncated at the N-ter minus relative to mouse SOX18. In situ hybridization analyses showed expres sion in the developing vasculature and feather follicles, consistent with r eported expression in the mouse embryo. In addition, cSox18 mRNA was observ ed in the retina and claw beds. (C) 2001 Elsevier Science B.V. All rights r eserved.