The differentiated cell types of the mature pituitary gland are defined on the basis of the hormone that they synthesize and secrete. The temporal appearance and spatial localization of terminally differentiated cell types in the developing chick anterior pituitary gland were characterized using in situ hybridization and immunohistochemistry to identify the presence of pituitary hormone transcripts and protein, respectively. Corticotropes expressing ACTH were detected at embryonic day 7 (E7), melanotropes expressing MSH and gonadotropes expressing FSHbeta/LHbeta were detected at E8, thryotropes expressing TSH were detected at E10, somatotropes expressing GH were detected at E12 and lactotropes expressing prolactin were detected at E14. Hormones were localized to distinct but overlapping regions of the pituitary gland, with the exception of growth hormone which was only present in the caudal lobe of the anterior pituitary gland. / The expression patterns of several transcription factors and signaling molecules that have been shown to participate in pituitary cell type differentiation in mice and zebrafish were also analyzed. The ventral diencephalon expresses Shh, Bmp4 and Fgf-10, suggesting that these signals may be critical for chick pituitary gland development, as demonstrated in other species. Similarly, the transcription factors Lim3, Pitx1, Pitx2 and Pit1 are likely to regulate gene expression patterns in the developing pituitary that are essential for the initial differentiation of Rathke's pouch and terminal differentiation of cell types.
| Identifer | oai:union.ndltd.org:LACETR/oai:collectionscanada.gc.ca:QMM.97986 |
| Date | January 2005 |
| Creators | Parkinson, Nicole. |
| Publisher | McGill University |
| Source Sets | Library and Archives Canada ETDs Repository / Centre d'archives des thèses électroniques de Bibliothèque et Archives Canada |
| Language | English |
| Detected Language | English |
| Type | Electronic Thesis or Dissertation |
| Format | application/pdf |
| Coverage | Master of Science (Department of Human Genetics.) |
| Rights | © Nicole Parkinson, 2005 |
| Relation | alephsysno: 002328994, proquestno: AAIMR24762, Theses scanned by UMI/ProQuest. |
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