Record Details
A histochemical study of oogenesis in the sea urchin, Strogylocentrotus purpuratus
ScholarsArchive at Oregon State University
| Field | Value |
|---|---|
| Title | A histochemical study of oogenesis in the sea urchin, Strogylocentrotus purpuratus |
| Names |
Chatlynne, Louise Geller
(creator) Harris, Patricia J. (advisor) |
| Date Issued | 1968-05-02 (iso8601) |
| Note | Graduation date: 1968 |
| Abstract | Oögenesis in the sea urchin Strongylocentrotus purpuratus was studied by histological methods and by histochemical techniques for polysaccharides, lipids, and nucleic acids Urchins were collected at Yaquina Head, Oregon at regular intervals between April 1966 and March 1967. An attempt was made to correlate seasonal variations in the coastal water temperature with the gonadal cycle. The ovaries of the sea urchin are large rebranched sacs covered with a flagellated peritoneal epithelium. Inside the peritoneum is a wall of collagenous connective tissue and smooth muscle. In the central portion of each saccule or acinus of the ovary are two main cell types: the sex cells, which develop into mature ova, and the accessory cells or nutritive phagocytes which apparently provide nutriment for the sex cells. Oögonia can be found through out the year in small groups scattered along the walls of the ovary, but are most numerous in the late spring and early summer when the ovary is spent. The oöcytes start growing in the late summer and early fall when the accessory cells, which were depleted of nutriments in the spent ovary, start filling with lipid and polysaccharide globules. At this time the accessory cells are also found to have inclusions that appear to be degenerate sex cells. In the late fall and early winter, the oöcytes continue to grow and their cytoplasm fills with lipid and polysaccharides. As the ova mature they move from the walls to the central portion of the acinus where they displace the accessory cells that had formerly been there. The ova that have been shed or are about to be shed contain pyranophilic RNA which is not found in the oöcytes. However, both ova and oöcytes have RNA that is stainable with azure B. The pyranophilic RNA is also found in accessory cells. Since all the oöcytes do not mature at the same time, a sea urchin is able to shed many times during the breeding season which lasts from late winter to early spring, During this period the accessory cells progressively lose their globules. When the accessory cells are finally depleted of their lipid and polysaccharide, the öócytes no longer grow and the ovaries are spent. |
| Genre | Thesis/Dissertation |
| Topic | Oogenesis |
| Identifier | http://hdl.handle.net/1957/47136 |
