Fig. 1. Single-cell RNA sequencing reveals candidate repressors of rDNA magnification.
A Model of R2 function in rDNA copy number (CN) maintenance. Expression of R2 when rDNA CN is reduced causes rDNA-specific R2 endonuclease activity to create double-stranded DNA breaks (DSBs) at the rDNA locus, which can lead to rDNA CN expansion by unequal sister chromatid exchange (USCE) during their repair. B UMAP 2-dimensional reduction of early germ cells and somatic cyst cells from combined low (bbZ9/Ybb0; UAS-upd/+; nos-Gal4/+) and normal rDNA CN upd over-expression testes (bbZ9/Ybb+; UAS-upd/+; nos-Gal4/+). Cell type clusters are germline stem cells (GSCs), spermatogonia (SG), and cyst stem cells (CySC). C Differential gene expression in GSCs from combined analyses. The lowest fold change and highest p-value produced for either analysis are displayed. Significance for differential gene expression analysis was determined by a non-parametric Wilcoxon rank sum test and adjusted for multiple comparisons using Bonferroni correction. D Differential gene expression in low rDNA CN GSCs and SG determined by cluster-based cell selection. Significant gene expression change indicated by a log2 fold change >0.25 or <−0.25. Source data are provided as a Source Data file.