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

Abstract

E(e pi theli al)-ca dh erin is a member of a ca lcium-dependent famil y of cell surface glycoproteins in vo lved in ce ll- ce ll adh esion and mo rph oge nesis. Catenins are a large family of proteins that connect the cad herins to the cytoskeleton. They are import ant for cadherin fUll ction and for transducing signals involved in specification of ce ll fate during embryogenesis. The best charac teri zed ca tenin s in clude U - , /3- , Yo, and p1 20- ca tenin. Usin g spec ifi c antibodi es, we studi ed th e ex pression and distribution of E-cadherin, and u- and /3 - catenin in developmental stages of Bufo arellarum toad. The three proteins were fo und co-locali zed in stages 19 to 41 of development. Surprisingly, E-cadherin was the only of these three proteins fo und earlier than stage 19. To test whe th e r E-ca dh e rin a nd /3- ca te nin have a functional role in B/./fo arenarlIIn embryogenesis, stage 17 whole embryos were incubated with anti-E-cadherin and /3-catenin antibodies. Both anti-E-cadherin and anti- /3- ca tenin antibodi es indu ced seve re morph ological alterations. However, while alterations produced by the anti-/3 -catenin antibody, showed some vari ability from the most severe (neural tube and notochord duplication) to a simple delay in deve lopment, the alterations with anti-E-cadherin were homogeneous. These observa tions suggest a critica l role for E-cadherin and/3-catenin in the ea rl y embryo ni c development of the Bufo arenarum toad. Our resul ts are consistent with the development al role of these proteins in other species. One of the most surprising findin gs was th e blockage with the anti-Bcat enin antibodi es on late r embr yo stages, and we hypothesize that the partial axes duplica tion could be medi ated by the notochord induction.