A ex-lacZ (green, single channel A’) expression in the testis was observed in the somatic lineage (Zfh1, blue, single channel A’“) near the hub (DE-cadherin, red, single channel A”).
B, C Clonal analysis, GFP (single channels, B’, C’) indicates the clone, Vasa (red) labels germ cells and Zfh1 (blue) CySCs and early cyst cells; the hub is indicated by a dotted line. GFP-labeled hpo mutant clones were generated by the MARCM technique and analyzed at 2 (B) and 14 dpci (C). Arrow (C, C’) shows displacement of wild-type GSCs by hpo mutant CySCs.
D Variation of average size of hpo mutant clones as a function of time. The data points (boxes) show the mean fraction of labeled CySCs in persisting clones. The black line shows a fit of the neutral drift model, modified to have a bias in favor of the labeled cell, to the data using an induction frequency of 10%. The dashed orange line represents the predicted clonal evolution if only a single CySC clone were induced with a time-shift of 3 days with the same set of parameters. For details of the biased drift model and the notation, see Supplementary Materials and Methods. n = 69, 64, 71, 43 for 2, 7, 14, 28 dpci, respectively. Error bars denote SEM.
E Distribution of clone sizes of persistent hpo mutant clones. The boxes show experimental data, and lines show the predictions of the model. Error bars denote SEM.
F Graph showing the number of GSCs at 14 dpci when CySC clones of the indicated genotype were present. Asterisks denote statistically significant change for the comparisons indicated. n = 26 (control), 36 (ptc), 47 (hpo), 15 (hpo; stg/+). Error bars denote SEM.
G, H YkiAct-overexpressing clones outcompeted both CySCs and GSCs at 14 dpci. Graph in (G) shows the number of GSCs when clones overexpressing YkiAct were present. Asterisks denote statistically significant change for the comparisons indicated. n = 15 (control), 19 (UAS-YkiAct). Error bars denote SEM. Clones are green (single channel H’), Vasa is red (single channel H”), and Tj is blue (single channel H”’). The hub is indicated by a dotted line.