Fig. 1.

Silencing of nhr-25 in the seam cells results in increased seam-cell numbers. Seam cells were counted in scm::nhr-25(RNAi) adult hermaphrodites expressing scm::gfp. Also see Table 1. (A) A schematic drawing representing the 16 seam cells in an adult worm, originating from H0-H2 cells (green), from V1-V6 cells (orange), and from the T seam cell (purple). Dashed rectangle marks the tail area shown in microscope image (B). (B) Example of an extra seam cell (arrow) in the tail. The other side of the worm tail displays the wild-type situation, with three posterior-most seam cells (area indicated by bracket). (C) Lineage diagram of T-seam-cell differentiation. Blue circles indicate cells that fuse with the hyp7 syncytium, green triangles mark seam cells, and rectangles represent neural cells; specifically, yellow rectangles symbolize phasmid socket cells and red rectangles symbolize other neural cells. Bracket indicates hypodermal cells, one of which probably maintained a seam-cell potential. (D,E) Expression of the nhr-25::gfp transgene in L1 wild-type hermaphrodites. Strong reporter activity appears in the seam cells V6, T and in the tail hypodermis (hyp) (D). (E) nhr-25::gfp expression in the T-cell daughters (T.a, T.p) and the tail hypodermis is indicated. Anterior is to the left.