Figure 2

Spermatogonial division is asynchronous across different cysts. (A) A testis from a white/yellow body pupa containing numerous cysts with germ cells undergoing division, as indicated by the presence of H3S10p (red). (B) A testis from a yellow body-red eye pupa containing a narrow region of cysts with germ cells undergoing division. The germ cells of most cysts in this testis are not undergoing division. However, a few single cells at the testis anterior appear to be dividing (red arrow). (C) A high magnification of a region within a testis containing two cysts undergoing division. Resolved chromosomes can be seen with high levels of H3S10p. (D) A high magnification of a region within a testis containing one cyst with germ cells undergoing division, in addition to several cysts with round, condensed nuclei and no H3S10p, indicating entry into spermiogenesis. Circumscribed cystocytes have condensed nuclei but are not H3S10p-positive, indicating that they have entered into spermiogenesis. Asterisks in (C,D) indicate some of the trophocyte nuclei. DNA is blue in all panels. Scale bar equals 40 μm in (B), 6 μm in (C), and 10 μm in (D).