Ontogeny of hamster placental lactogen-II / by Melissa A. Roberts.
| Author/creator | Roberts, Melissa A. author. |
| Other author | Renegar, Randall H., degree supervisor. |
| Other author | East Carolina University. Department of Biology. |
| Format | Theses and dissertations |
| Production | 1992. |
| Description | 89 leaves : illustrations ; 28 cm |
| Supplemental Content | Access via ScholarShip |
| Subjects |
| Subject | The purpose of this investigation was to identify the cell types responsible for hamster placental lactogen-II (haPL-II) synthesis in the chorioallantoic placenta. In addition, temporal changes in haPL-II mRNA expression within the placenta, placental mass, and the proportion of haPL-II containing cells per unit area were examined to determine whether these factors contribute to the maternal haPL-II serum profile. Hamster PL-II mRNA expression was assessed by in situ hybridization and Northern and slot blot analysis. Hamster PL-II protein synthesis was determined by immunocytochemical techniques. Placenta were recovered in the morning on Days 6, 8, 10, 12, and 14 of gestation and in the afternoon on Day 15. Expression of haPL-II mRNA and protein were first observed in placental sections on Day 12 of gestation and continued to Day 15. Throughout gestation giant trophoblast cells (GTC) of the trophospongium were the major source of haPL-II mRNA and protein; although, GTC along the placenta's periphery and in the labyrinth expressed haPL-II as well. The number of haPL-II immunostained GTCs per unit area increased between Days 12 and 14 and remained elevated to Day 15. Northern analysis of total placental RNA for haPLII mRNA detected a single 1-kb transcript. Messenger RNA was first detected on Day 10 of gestation by Northern and slot blot analysis, and densitometric analysis of slot blots demonstrated a significant increase in the percentage of haPL-II message present in the placenta as gestation advanced. Placental weight and the percentage of total placental weight contributed by the trophspongium increased between Days 12 and 15. These observations indicate that an increase in the number of GTCs that produce haPL-Il is a major factor contributing to the increase in maternal haPL-II serum levels during pregnancy. |
| General note | Submitted to the faculty of the Department of Biology. |
| General note | Advisor: Randall H. Renegar |
| Dissertation note | M.S. East Carolina University 1992 |
| Bibliography note | Includes bibliographical references (leaves 57-65). |
| Genre/form | Academic theses. |
| Genre/form | Academic theses. |
| Genre/form | Thèses et écrits académiques. |
Availability
| Library | Location | Call Number | Status | Item Actions |
|---|---|---|---|---|
| Joyner | University Archives | ASK AT SPECIAL COLLECTIONS DESK | ✔ Available | Request Material |
| Electronic Resources | ✔ Available |