SEQUENCE AND DISTRIBUTION OF XENOPUS-LAEVIS E-CADHERIN TRANSCRIPTS

Cadherins are calcium-dependent adhesive glycoproteins implicated in h istogenetic processes. In Xenopus laevis, the distribution of classica l cadherins N, E, EP, XB and U has been determined by immunofluorescen ce labeling or by in situ hybridization. In this study, we report the full-length sequence of the E-cadherin cDNA. Comparison with the other cadherin sequences available indicates that Xenopus E-cadherin is as homologous to Xenopus EP-cadherin as to the chicken L-CAM and to the m ammalian E-cadherin. Although Xenopus E-cadherin protein sequence exhi bits many short conserved motifs present in other E-cadherins, it diff ers remarkably from the chicken L-CAM and the mammalian E-cadherin in its appearance after gastrulation. In situ hybridization data showed t hat E-cadherin transcripts are homogenously distributed in all differe ntiating epithelia from early tailbud to post-metamorphic stage. In co ntrast to mouse E-cadherin, Xenopus E-cadherin was not detected transi ently in the nervous system during embryogenesis and in the post-metam orphic stages.