Fig. 2.

Desilencing of a repetitive transgene in Mes (M⁻Z⁺) mutants. A repetitive let-858∷gfp reporter extrachromosomal array was transferred into the different mes genetic backgrounds shown and assayed for desilencing in M⁻Z⁺ cross-progeny, as diagrammed in Fig. 1B. Adult gonad arms housing germline nuclei are outlined in A, C and D; arrowheads in B indicate representative germ cell nuclei. (A,B,D) Hermaphrodite gonads; (C) male. To illustrate the complete silencing of the array in a mes⁺ background, a control animal from the original line carrying the array is shown in A. (B,C,D) Expression of the reporter in the germlines of Mes worms. The bracket 1 in B outlines germ cells that are more distal, and presumably immature, and bracket 2 outlines others that are beginning to degenerate; GFP activity is not evident in these bracketed cells. Desilencing in the mes mutants was also not observed in earlier larval stages (L2,L3), where the germline is more generally proliferative (not shown). Scale bar, approximately 30 μm.