Developmental expression and regulation of the chemokine CXCL14 in Xenopus.

Chemokines are a family of proteins originally identified for their activity promoting the recruitment of leukocytes to inflammatory sites. Recent evidence indicates that chemokines and their receptors may also regulate key developmental processes. In this paper we report the expression and regulation of the chemokine CXCL14 during Xenopus laevis embryogenesis. CXCL14 is first detected in several ectoderm derivatives, the dorsal aspect of the retina, the cement gland and the hatching gland. Later in development, additional domains of expression include the head mesenchyme and the medial ventral aspect of the otic vesicle. CXCL14 expression in the ectoderm is regulated by both Bmp and canonical Wnt signaling. In the hatching gland CXCL14 is co-expressed with the transcription factor Pax3. Using gain of function and knockdown approaches in whole embryos and animal explants we show that Pax3 is both necessary and sufficient for CXCL14 expression in this domain of the ectoderm.