Figure 3

Expression of Nvi-ParaHox genes during formation of postlarval neuromeres. (a, b) Expression of Nvi-Gsh. Expression occurs in several newly formed segments (a), and then disappears in the older segments until only a single pair of cells expressing the gene remains (b). (c, d) Expression of Nvi-Xlox. Initial Nvi-Xlox expression occurs in segments that are older and more posterior than those expressing Nvi-Gsh (a, c). Nvi-Xlox positive cells are localized in the anterior part of the segment below the segmental border (d). (e, f) Expression of Nvi-Cad. Early Nvi-Cad expression occurs in newly formed segments, but this expression disappears rapidly. The worm in (e) was stained with TO-PRO-1. Nvi-Cad expression in newly formed segments can also be detected during posterior regeneration. Nvi-Cad positive cells are situated close to the central part of segments or a little bit to the posterior, hence in the most posterior part of the neuromere (f). Black arrowhead marks the segmental border; white arrowhead marks the growth zone.