Figure 5. Capsids accumulate in the mid-pachytene gonad core as adults age at 15°C.

(A–D) Longitudinal, optical sections through gonads showing increased accumulation of capsids (green) with adult age, as indicated. The gonad in panel B is immunostained for HIM-4/hemicentin (red) to visualize the apical membrane (see Figure 1B). Note that capsids localize predominately in the core, outside the ring channel and away from nuclei (blue, DAPI). (C) Capsids grouped in wavy lines and tangles of lines in the mid-pachytene region of a day 3 adult. (D) Low magnification of the mid-pachytene region. Note variation in capsid abundance between the two sides of the gonad core (double-headed arrow), and that the wavy lines of capsids disappear as germ cells move proximally into late pachytene (bracketed region). (E–G) The late-pachytene/diplotene region, stained and imaged as for panel B; two of the somatic sheath cells that surround the gonad are visible in this image. Germ cells from regions F and G are shown at high magnification, oriented as in Figure 1B. An optical rotation of a similar region of the gonad is shown in Supplemental Video S1. (H) Optical section through germ nuclei in the late-pachytene/diplotene region showing capsids (green) and P granules (red, αPGL-1). Note that capsids localize close to the nuclear envelope, but most are not directly on, or within, P granules. Electron micrographs of capsids within P granules are shown in Supplemental Figure S1H. Scale bars: A–C, F–H (5 µm), D–E (10 µm).