Int. J. Dev. Biol. 48: 1119 - 1129 (2004)

https://doi.org/10.1387/ijdb.041892km

Vol 48, Issue 10

X-epilectin: a novel epidermal fucolectin regulated by BMP signalling

Original Article | Published: 1 December 2004

Karine Massé¹, Rebecca Baldwin², Mark W. Barnett³ and Elizabeth A. Jones*^,1

¹Molecular Physiology, Department of Biological Sciences, Warwick University, Coventry, U.K., ²Paterson Institute for Cancer Research, Manchester, U.K. and ³Department of Biomedical Sciences, University of Edinburgh, Edinburgh, U.K.

Abstract

This paper reports the cloning and characterisation of a new posterior epidermal marker, X-epilectin, in Xenopus laevis. This gene encodes for a fucolectin, which belongs to the lectin superfamily of carbohydrate binding proteins and specifically binds fucose residues. RT-PCR and in situ hybridisation show that the expression of this gene is switched on during gastrulation and up-regulated during neurula stages and found expressed ubiquitously throughout the epidermis. From tailbud stages, the expression is limited to the dorsal posterior region of the embryo, suggesting that X-epilectin expression is regulated along anteroposterior and dorsoventral gradients during development. In the adult, X-epilectin is mainly expressed in intestinal components, kidney, spinal cord and skin. The effects of growth factors on the regulation of X-epilectin were studied. Change of the fate of animal caps into cement gland or dorsal mesoderm induces a down-regulation of X-epilectin expression in explants treated respectively with ammonium chloride and activin A. We also show that X-epilectin expression is down-regulated by Noggin and tBR and that this effect is inhibited by BMP4 over-expression, suggesting X-epilectin expression is mediated by the BMP signalling pathway.

Keywords

fucolectin, Xenopus laevis, epidermis, BMP signalling, anteroposterior axis