Figure 6.

mei-P26 Is a Major Target of CCR4-Mediated Translational Repression for GSC Self-Renewal

(A–D) Upregulation of Mei-P26 protein levels in twin, pum, and nos mutant GSCs. Wild-type (A), twin^DG24102 (B), pum^MSC/pum⁰¹⁶⁸⁸ (C), and nos¹⁸/nos⁵³ (D) germaria from 3-day-old females stained with anti-Mei-P26 antibody (green). The merges between anti-Mei-P26 (green) and 1B1 (red) are shown in (A′–D′). White arrows indicate GSCs. Scale bars represent 10 μm.

(E) Quantification of fluorescence intensity ratios between GSCs and cysts in the four genotypes shown in (A–D). The numbers of germaria used in the quantification were 44 wild-type, 22 twin^DG24102, 24 pum^MSC/pum⁰¹⁶⁸⁸, and 14 nos¹⁸/nos⁵³. Error bars represent SD. ^∗p = 0.01, ^∗∗∗p = 0.0007, and ^∗∗∗∗p < 0.0001 using the t test.

(F and G) Upregulation of Mei-P26 protein levels in twin mutant clonal GSCs. (F) Example of twin^DG24102 mosaic germarium labeled with GFP (green), 1B1 (purple), and anti-Mei-P26 (red) 7 days after clone induction. The white arrow indicates the twin^DG24102 clonal GSC (lack of GFP) and the white arrowhead indicates the twin^DG24102/+ heterozygous GSC. Scale bars represent 10 μm. (G) Quantification of fluorescence intensity of Mei-P26 staining in twin^DG24102/+ heterozygous and twin^DG24102 clonal GSCs. n = 8 germaria. Bars represent means with SD. ^∗∗p = 0.0088 using the t test.

(H and I) Rescue of twin^DG24102 mutant phenotype of GSC loss by decreasing the gene dosage of mei-P26. twin^DG24102 (H and H′) and mei-P26^fs1/+; twin^DG24102 (I and I′) ovaries labeled with 1B1 (green) and anti-Vasa (red) in 7-day-old females. (I) The white arrows indicate GSCs; oogenesis appears normal. Scale bars represent 20 μm in (H) and 60 μm in (I).

(J) Quantification of germaria containing at least one GSC in twin^DG24102, mei-P26^fs1/+; twin^DG24102 and mei-P26^mfs1/+; twin^DG24102 mutant females of 3, 7, 14 and 21 days. n represents the number of germaria scored.