Record Details
The giant cells in the chorio-allantoic placenta of the golden hamster (Mesocricetus auratus Waterhouse)
ScholarsArchive at Oregon State University
| Field | Value |
|---|---|
| Title | The giant cells in the chorio-allantoic placenta of the golden hamster (Mesocricetus auratus Waterhouse) |
| Names |
Ritschard, Ronald Laird
(creator) Hillemann, Howard H. (advisor) |
| Date Issued | 1966-04-29 (iso8601) |
| Note | Graduation date: 1966 |
| Abstract | This study deals with the autoradiographic analysis, using a DNA precursor (tritiated thymidine), of the trophoblastic giant cells in the placentae of the golden hamster (Mesocricetus auratus Waterhouse), beginning with the sixth day of gestation and extending to term on day sixteen. Both the percent of labelled cells in the sample population along with the average number of grains per cell, for five regional types of giant cells are presented. The obplacental giant cells, after day 11, show an increase in the average grain count without undergoing cell division and in consequence increase their chromosome number. The ectoplacental cone giant cells (Trager) show no change in tritium label and thus remain diploid. After the giant cells of the ectoplacental cone become predominant in both the trophospongium and the labyrinth, they increase their rate of DNA synthesis without undergoing cell division and hence become polyploid. Tertiary giant cells, found in the maternal blood vessels, also show an increase in average grain counts. The giant cells of the chorionic plate, remnants left behind by the advancing ectoplacental cone, do not undergo polyploidization. The obplacental giant cells are important in implantation, as an anchor for Reichert's membrane, and as a possible source of hormones. It appears that the trophospongial giant cells are significant throughout gestation, while those of the labyrinth become less important as gestation proceeds. The most decisive period in the development of the hamster placenta, so far as the trophoblastic giant cells are concerned, lies between day 11 and day 12. There was no investigation of the level of polyploidy for any of the giant cell types in this study. |
| Genre | Thesis/Dissertation |
| Topic | Cells |
| Identifier | http://hdl.handle.net/1957/48556 |
