FIGURE 3. Prolonged activity for the stem cell population in raf-deficient testes.
From the following article:
Somatic control over the germline stem cell lineage during Drosophila spermatogenesis
John Tran, Tamara J. Brenner and Stephen DiNardo
Nature 407, 754-757(12 October 2000)
doi:10.1038/35037613
a, WT testis, X-gal activity; M5-4 expressed in the hub (arrowhead),
germline stem cells (large arrow), and gonialblasts (smaller arrow). b
, raf-deficient testis; M5-4 is expressed in many cells near hub
(arrowhead). c, WT testis, day 19; expression solely in hub. d,
raf-deficient testis, day 19. e, WT testis, day 19; branched fusomes
(green) are visible further along the testis (arrow), but there are no cells
with spherical fusomes adjacent to hub (arrowhead). f, raf-deficient
testis, day 19; an example of late-interphase (nuclear Anillin, red) germline
stem cell (arrow), as indicated by the presence of a spherical fusome (green)
in the cell adjacent to the hub (arrowhead). Scale bar, 40 
m.