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Fig. 1. Schematic of stage 6 (A) and 10 (B) follicles. In all figures, follicles
are arranged with anterior towards the left. The arrangement and fates of
different cells are indicated by the colors of their nuclei: oocyte (dark
brown), nurse cells (light brown), central follicle cells (gray), polar cells
(red), stalk cells (light blue), outer border cells (green), stretched cells
(pink), centripetal cells (dark blue) and posterior terminal cells (black).
Although it is thought that the border, stretched and centripetal cells are
specified by stage 6, no markers are available to differentiate them until
later.