FIGURE 3 in Sperm structure in Parasitidae mites (Parasitiformes: Mesostigmata: Gamasina)

FIGURE 3: Heteroparasitus tirolensis, TEM. (A) Deferent duct (dd) containing several spermatozoa cross-sectioned at different levels. Section through nuclear region (1) shows nucleus (n) containing chromatin (white asterisk), sIBs surrounding nucleus and subplasmalemmal ribbons (rb). Sperm sectioned more caudally (2) shows the same organization; note different appearance of ribbons (left and right side) in sperm section close to the caudal end of nucleus (3). In sections at postnuclear region (4) gIBs are scattered among mitochondria (m). Posterior end of spermatozoon (5) is filled with flocculent material; there are also some mitochondria (m) and subplasmalemmal cisterns (sc). Deferent duct cells contain conspicuous RER filled with a moderately dense material (black asterisks) and electron-dense granules (arrows) in cytoplasm. Deferent duct is surrounded by visceral muscle cells (vmc). (B) Sperm section through nuclear region (left) showing nuclear material (n), sIBs, ribbons (rb) alternating with mitochondria (m), and subplasmalemmal cisterns (sc). Section of postnuclear region (right) adhering to deferent duct cell (dd) shows ribbons (rb) and subplasmalemmal cisterns (sc) surrounding gIBs and mitochondria (m). Note different density of ribbons in both sperm regions. (C) Posterior end of spermatozoon as (5) in (A), enlarged. Regularly distributed cisterns (sc) surround flocculent material (asterisk) with several mitochondria (m). Arrow indicates electron-dense, apparently secretory granules in deferent duct (dd) cell. Scale bars: 5 µm (A); 1 µm (B, C). Abbreviations: dd – deferent duct cell; gIB – granular inclusion body, m – mitochondrion, n – nucleus, rb – subplasmalemmal longitudinal ribbon, RER – rough endoplasmic reticulum in deferent duct cell, sc – subplasmalemmal cistern, sIB – striated inclusion body, vmc – visceral muscle cell