Figure 2.

Experimental design of the homeotic construction and morphogenetic regulation pattern. The homeotic construction was made in the antecerebral end by transections and grafting between two individuals of Lineus ruber to substitute the anterior ocellar region from the donor for the posterior postocellar region of the recipient. This resulted in an experimental homeotic chimera with a duplication of the ocellar region and a deletion of the postocellar region. Pairs of worms differing in pigmentation were chosen to distinguish host and donor tissue.