Fig. 4: Defective sperm release in enDΔ mutant testis.

Five-day-old adult testis with the sperm tails labelled with Dj::GFP (green, or grey) in control heterozygous (a, c) or homozygous enDΔ males (d). b Schematic drawing of the Drosophila melanogaster wild-type testis terminal region indicating (1) the Head Cyst Cells (HCC, green) tightly holding the sperm heads (yellow); (2) the coiled sperms and (3) the sperms after their release to the seminal vesicle. c Close-up of the squared region in a. In heterozygous males (a, c) spermiation leads to sperm accumulation in the seminal vesicle (asterisk). In homozygous enDΔ males (d) sperms cannot be detected in the seminal vesicle (asterisk) nor in the distal part of the terminal testis region (right of the discontinuous yellow line). e, f Testes with the sperm tails labelled with Axo49 (magenta) in the testis terminal region and seminal vesicle (asterisk) of control heterozygous (e) or enDΔ homozygous (f) males. All testes are counter-stained with DAPI (yellow). In (a, c, d) filamentous Actin is labelled with Rhodamine phalloidin (magenta). Scale bar: 100 µm.