FROM CELLS TO PRIMMORPHS AND ADULT SPONGES: AN APPROACH TO UNDERSTAND THE BAUPLAN OF DEMOSPONGIAE

Abstract

Molecular data suggest that the phylum Porifera with its three classes, Hexactinellida, Demospongiae and Calcarea consists of two groups, sponges with a siliceous skeleton (Hexactinellida and Demospongiae) and those possessing a calcareous skeleton (Calcarea). Recent data indicate that all Metazoa, including the Porifera evolved from one common ancestor, the Urmetazoa. The Demospongiae are provided not only with the basic molecules for cell-cell and cell-matrix interactions but also with elements allowing a distinct pattern formation. The studies reviewed have been primarily performed with intact demosponges (Suberites domuncula) but also with primmorphs, a special form of 3D aggregates derived from them.