title: Abnormal spermatogenesis in the common liver fluke (Fasciola sp.) from Japan and Korea.
abstract: Diploid and triploid specimens of Japanese and Korean Fasciola sp. showed abnormality in their spermatogenesis. Live germ cells obtained from the testes were observed under a differential interference contrast microscope. In the stages from spermatogonium to spermatid, the cells combined together at the central cytoplasmic bridge during a series of divisions. One spermatogonium becomes a cell group of 8 primary spermatocytes through 3 mitoses. Until the primary spermatocyte stage, cells are divided in a uniform manner. In most of the diploid specimens, the primary spermatocytes are irregularly divided into non-uniform secondary spermatocytes, however, some specimens perform a regular division. In the majority of triploid flukes, the primary spermatocytes are divided in a regular pattern, but some of the specimens perform an irregular division. The non-uniform spermatids do not perform a spermiogenesis. In the diploid specimens, no spermatozoa were found that were produced by spermiogenesis. Whereas in the triploid specimens, some spermatids distributed uniformly on the surface went through a spermiogenesis. We observed some moving spermatozoa in one triploid specimen. The spermatozoa possibly retain their normal reproductive function.
authors.affiliation: St. Mary's Junior College, Fukuoka, Japan.
authors.forename: K
authors.initials: K
authors.lastname: Terasaki
authors.forename: N
authors.initials: N
authors.lastname: Moriyama-Gonda
authors.forename: Y
authors.initials: Y
authors.lastname: Noda
mesh_terms: D000818:Animals; D004171:Diploidy; D005209:Fasciola / Q000235:genetics* / Q000502:physiology; D007564:Japan; D007723:Korea; D008297:Male; D011123:Polyploidy; D013091:Spermatogenesis / Q000235:genetics*