Fig. 4. Hr39 controls spermathecal secretion. Electron microscopy images of wild-type and Hr39 mutant spermathecae (SP) and parovaria (P). (A-D) Wild-type SP. (A) Gland cells (red outline) surround the lumen (L). N, nucleus; EA, end apparatus. Scale bar: 10 µm. (B) SP lumen with sperm (S) surrounded by extracellular material (M). Scale bar: 2 µm. (C) EA in active state showing secretion. Scale bar: 2 µm. (D) EA (white outline) showing little secretion among the microvilli. Scale bar: 2 µm. (E) Wild-type parovaria with little secretion. Scale bar: 10 µm. (F) Hr39⁰⁷¹⁵⁴ SP containing less secretory product than wild type (C). Scale bar: 2 µm. Red arrows indicate SP secretion; L, lumen; M, luminal material; S, sperm.