Fig. 8. MRG-1 is required for silencing of a transgene and several X-linked genes in the germ line of mrg-1 M+Z-mutants. (A,B) Control adult hermaphrodite stained with Hoechst 33342 [as done in Garvin et al. (Garvin et al., 1998); B] and displaying expression of LET-858::GFP fluorescence in somatic nuclei but not in the germ line. None of 27 worms analyzed displayed GFP in the germ line. (C,D) mrg-1 (M+Z-) adult hermaphrodite stained with Hoechst 33342 (D) and displaying LET-858::GFP fluorescence in germ nuclei as well as somatic nuclei (C). Of 26 worms analyzed, 25 displayed GFP in the germ line. Brackets indicate the germ line. (E) RT-PCR comparison of mRNA levels from five X-linked and four autosomal genes in dissected wild-type and mrg-1(qa6200) M+Z-gonads. #1 and #2 show the results from two independent sets of dissected gonads. For each gene, RT-PCR was performed in triplicate. Transcript levels are relative to the reference gene ZK381.1/him-3 (Bender et al., 2006). The five X-linked genes are upregulated in mes-4 mutant gonads compared with wild type (Bender et al., 2006). Upregulation of those X-linked genes was also observed in mrg-1 gonads. The four autosomal genes are expressed at approximately equivalent levels in mes-4 and wild-type gonads (Bender et al., 2006). mrg-1 and wild-type gonads also accumulate similar levels of those genes.