Molecular specification of cell lines in the embryo of Platynereis (Annelida).

In this study we describe the site and moment of histospecific differentiation in developmental stages of the annelid Platynereis dumerilii by use of biochemical markers. The monoclonal antibody (mab) OI7 and uncloned hybridoma supernatants (pAb's) OI8, OI10, OI46 and OI69 recognize neural antigens that appear asynchronously during development. By an enzymatic test, acetylcholinesterase (AChE) was found specific for nervous tissue as well.

Evidence of coelomic substances inducing genital maturation inPerinereis cultrifera (annelida polychaeta).

Two peptides (B and B) have been isolated from the coelomic fluid ofPerinereis cultrifera. These peptides are absent in sexually undifferentiated animals. They appear and become abundant during the oocyte submaturity stage.