Cytoplasmic organelles present during spermatogenesis in the free-living nematode Panagrellus silusiae

Abstract

By electron microscopy it was found that two kinds of cytoplasmic organelles occur during spermatogenesis in the free-living nematode Panagrellus silusiae. One type of organelle is called a vesicular body (v-body) and lines the complete internal cell surface of the spherical and aflagellate sperm. V-bodies (about 0.35 μm × 0.6 μm) are formed in the primary spermatocytes and after meiosis they migrate to the surface of the spermatid. In the primary spermatocytes, before the appearance of v-bodies, many double membrane - bound, ovoid crystalline bodies (c-bodies) are formed. These bodies (about 0.5 μm × 0.7 μm) subsequently degenerate and no trace of their fibrillar material is observed in the spermatozoon.The mature sperm is devoid of microtubules, centrioles, Golgi material, and acrosomal-like structures; however, numerous mitochondria lie beneath the surface vesicles and in the central region of the mature sperm the chromatin occurs as discrete condensed clumps.