|Ultrastructural study of the mature oocyte of Tethya aurantium (Porifera: Desmospongiae)|
Sciscioli, M.; Lepore, E.; Mastrodonato, M.; Scalera Liaci, L.; Gaino, E. (2002). Ultrastructural study of the mature oocyte of Tethya aurantium (Porifera: Desmospongiae). Cah. Biol. Mar. 43: 1-7
In: Cahiers de Biologie Marine. Station Biologique de Roscoff: Paris. ISSN 0007-9723, more
Reproduction; Symbionts; Ultrastructure; MED, Adriatic [Marine Regions]; Marine
|Authors|| || Top |
- Sciscioli, M.
- Lepore, E.
- Mastrodonato, M.
- Scalera Liaci, L.
- Gaino, E.
This ultrastructural study of the oocyte of Tethya aurantium adds new data to the knowledge of the germinal cells in the sponges of this genus. The ooplasm contains lipid droplets, electron-dense globules, phagosomes and rod-like inclusions. The most interesting feature of the oocytes is the high number of bacteria which are present in phagocytotic vacuoles in the oocyte cytoplasm and which derive from the mesohyl. While in other sponges the vacuoles usually contain a single bacterium, in T. aurantium the vacuoles are large and contain groups of bacteria. The bacteria engulfed by the oocytes of T. aurantium may perform a trophic role but their presence may also be interpreted as a means of transfer to the embryos. The lack of nurse cells around the oocytes suggests that yolk production in T. aurantium occurs by active uptake of nutrients from the mesohyl.