Fig. 3.

The methyltransferase activity of Set1 is required for its function in the male germline. (A) Quantification of the percentage of testes with the representative germline phenotypes, germ cell loss and early-germline overpopulation, present in nos>set1 RNAi testes at 1 day and 5 days post-eclosion (adapted from Fig. 1D). (B-E) Schematics of the Set1 cDNA transgene with the RNAi recognition sequences mutated, named WT rescue (B); the Set1 cDNA transgene with the RNAi recognition sequences mutated and an E→K amino acid change in the SET domain, named Mut rescue (C); the Set1 cDNA transgene without the RNAi recognition sequences mutated, named WT (D); the GFP cDNA with the nuclear localization sequence, named GFP (E). (B′-E′) Representative images of nos>WT Rescue, set1 RNAi testis (B′), nos>Mut Rescue, set1 RNAi testis (C′), nos>WT, set1 RNAi testis (D′) and nos>GFP, set1 RNAi testis (E′). All testes are from males 5 days post-eclosion, immunostained with H3K4me3 (magenta), GFP (green), Fas III (yellow) for the hub region, 1B1 (yellow) for spectrosome and fusome, and Tj (yellow) for the CySC lineage cells. Right-hand panels show higher magnification images of an example germ cell expressing the corresponding transgenes (outlined by white dashed lines). Scale bars: 20 μm (testis); 5 μm (individual germ cell images). (B″-E″) Quantification of the percentage of testes with the representative germline phenotypes, germ cell loss and early-germline overpopulation, present in nos>WT Rescue, set1 RNAi testes (B″), nos>Mut Rescue, set1 RNAi testes (C″), nos>WT, set1 RNAi testes (D″), nos>GFP, set1 RNAi testes (E″), at 1 and 5 days post-eclosion.