Ray and inter-ray blastemas interact to control bifurcations of Danio rerio fin rays

Teleost fin rays bifurcations are characteristic of each fin ray of the fis hes. These structures are formed of two parenthesis-like dermal bones (hemi -rays) and surrounded by a loose connective tissue and a multistratified pl anar epidermis. Each ray is joined to their neighbour rays by the interray. The interray is composed of a loose connective tissue surrounded by the ep idermis (Becerra et al, 1983). In previous works we have shown the necessit y of tissues neighbour to the ray blastema for a proper bifurcation (Mari-B effa et al, 1996, 1999). In this communication we present evidences in favo ur of the hypothesis that the interray blastema. is specifically necessary for a proper differentiation of the bifurcation processes in each ray durin g regeneration in Danio rerio (Hamilton-Buchanan) (Cyprinidae, Teleostei).