Alterations induced by E-cadherin and beta-catenin antibodies during the development of Bufo arenarum (Anura-Bufonidae)

E(epithelial)-cadherin is a member of a calcium-dependent family of cell su rface glycoproteins involved in cell-cell adhesion and morphogenesis. Caten ins are a large family of proteins that connect the cadherins to the cytosk eleton. They are important for cadherin function and for transducing signal s involved in specification of cell fate during embryogenesis. The best cha racterized catenins include alpha-, beta-, gamma-, and p120-catenin. Using specific antibodies, we studied the expression and distribution of E-cadher in, and alpha- and beta -catenin in developmental stages of Bufo arenarum t oad. The three proteins were found co-localized in stages 19 to 41 of devel opment. Surprisingly, E-cadherin was the only of these three proteins found earlier than stage 19. To test whether E-cadherin and beta -catenin have a functional role in Bufo arenarum embryogenesis, stage 17 whole embryos wer e incubated with anti-E-cadherin and beta -catenin antibodies. Both anti-E- cadherin and anti-beta -catenin antibodies induced severe morphological alt erations. However, while alterations produced by the anti-beta -catenin ant ibody, showed some variability from the most severe (neural tube and notoch ord duplication) to a simple delay in development, the alterations with ant i-E-cadherin were homogeneous. These observations suggest a critical role f or E-cadherin and beta -catenin in the early embryonic development of the B ufo arenarum toad. Our results are consistent with the developmental role o f these proteins in other species. One of the most surprising findings was the blockage with the anti-beta -catenin antibodies on later embryo stages, and we hypothesize that the partial axes duplication could be mediated by the notochord induction.