Figure 3

Sperm tail formation in the N. vitripennis testis. Regions in the testis of yellow body-red eye pupa devoid of nuclei (A) are filled with extending sperm tails (microtubules are green; DNA is blue). (B–D) Microtubules are enriched outside but not inside of cysts at the apical end of the testis. (B) is a merge; (C) is microtubules in greyscale; (D) DNA in greyscale. (E–G) Germ cells in a more posterior-located cyst have entered into spermiogenesis, as indicated by their condensed nuclei. The microtubules have begun to become enriched within each cell (E is a merge; F is microtubules in greyscale; G is DNA in greyscale). (H–J) A bundle of spermatids with elongating tails, whose ends coalesce into a ‘cone’ like structure. (H) is a merge of microtubules in green and DNA in blue. The arrow in (H,J) indicates the elongating nuclei that are tightly organized into a cup. (I) Microtubules is in greyscale; (J) DNA is in greyscale. Scale bar equals 50 μm in (A), 10 μm in (D), and 15 μm in (H).