title: Ultrastructure of spermatogenesis in the testis of Paragonimus heterotremus.
abstract: Lung fluke, Paragonimus heterotremus, is a flatworm causing pulmonary paragonimiasis in cats, dogs, and humans in Southeast Asia. We examined the ultrastructure of the testis of adult P. heterotremus with special attention to spermatogenesis and spermiogenesis using scanning and transmission electron microscopy. The full sequence of spermatogenesis and spermiogenesis, from the capsular basal lamina to the luminal surface, was demonstrated. The sequence comprises spermatogonia, spermatocytes with obvious nuclear synaptonemal complexes, spermatids, and eventual spermatozoa. Moreover, full steps of spermatid differentiation were shown which consisted of 1) early stage, 2) differentiation stage representing the flagella, intercentriolar body, basal body, striated rootlets, and electron dense nucleus of thread-like lamellar configuration, and 3) growing spermatid flagella. Detailed ultrastructure of 2 different types of spermatozoa was also shown in this study.
authors: Department of Anatomy, Faculty of Medicine, Khon Kaen University, Muang, Khon Kaen 40002, Thailand.
authors: Nongnut
authors: N
authors: Uabundit
authors: Department of Anatomy, Faculty of Medicine, Khon Kaen University, Muang, Khon Kaen 40002, Thailand.
authors: Pipatphong
authors: P
authors: Kanla
authors: Department of Anatomy, Faculty of Medicine, Khon Kaen University, Muang, Khon Kaen 40002, Thailand. ; Department of Anatomy, Faculty of Medical Science, Naresuan University, Muang, Phitsanulok 65000, Thailand.
authors: Phongphithak
authors: P
authors: Puthiwat
authors: Department of Anatomy, Faculty of Medicine, Khon Kaen University, Muang, Khon Kaen 40002, Thailand.
authors: Channarong
authors: C
authors: Arunyanart
authors: Department of Anatomy, Faculty of Medicine, Khon Kaen University, Muang, Khon Kaen 40002, Thailand.
authors: Kowit
authors: K
authors: Chaiciwamongkol
authors: Department of Parasitology, Faculty of Medicine, Khon Kaen University, Muang, Khon Kaen 40002, Thailand. ; Research and Diagnostic Center for Emerging Infectious Diseases, Khon Kaen University, Muang, Khon Kaen 40002, Thailand.
authors: Wanchai
authors: W
authors: Maleewong
authors: Department of Parasitology, Faculty of Medicine, Khon Kaen University, Muang, Khon Kaen 40002, Thailand. ; Research and Diagnostic Center for Emerging Infectious Diseases, Khon Kaen University, Muang, Khon Kaen 40002, Thailand.
authors: Pewpan M
authors: PM
authors: Intapan
authors: Department of Anatomy, Faculty of Medicine, Khon Kaen University, Muang, Khon Kaen 40002, Thailand.
authors: Sitthichai
authors: S
authors: Iamsaard
authors: Department of Anatomy, Faculty of Medicine, Khon Kaen University, Muang, Khon Kaen 40002, Thailand.
authors: Wiphawi
authors: W
authors: Hipkaeo
mesh_terms: D000818:Animals; D008297:Male; D008855:Microscopy, Electron, Scanning; D046529:Microscopy, Electron, Transmission; D010238:Paragonimus / Q000502:physiology* / Q000648:ultrastructure*; D013091:Spermatogenesis; D013094:Spermatozoa / Q000648:ultrastructure; D013737:Testis / Q000648:ultrastructure
keywords: Paragonimus heterotremus; lung fluke; spermatogenesis; spermiogenesis; testis; ultrastructure