|Cytological aspects of oligochaete spermiogenesis|
Ferraguti, M. (1984). Cytological aspects of oligochaete spermiogenesis. Hydrobiologia 115: 59-64
In: Hydrobiologia. Springer: The Hague. ISSN 0018-8158, more
|Also published as |
- Ferraguti, M. (1984). Cytological aspects of oligochaete spermiogenesis, in: Bonomi, G. et al. (Ed.) Aquatic Oligochaeta: Proceedings of the 2nd International Symposium on Aquatic Oligochaete Biology, held in Pallanza, Italy, September 21-24, 1982. Developments in Hydrobiology, 24: pp. 59-64, more
Spermiogenesis in Oligochaeta occurs with peculiar modalities, common to all the species studied in this group. Gonial cells, produced in the testes, drop into coelomatic cavities (usually seminal vesicles) where they undergo a series of mitotic divisions, without cytodieresis, and finally meiosis. In the seminal vesicles, a series of 'morulae' is present, composed of 2, 4, 8, 18, 32, . . . cells. The number of spermatids produced is variable, but is constant for each species. The process of spermiohistogenesis involves many steps, including: nuclear shaping, chromatin condensation, production of an acrosome, reduction of the number of mitochondria. The present knowledge of the mechanisms of cell differentiation, and the problem of the presence of two different sperm lines in some species is discussed.