Expression patterns of hormones, signaling molecules, and transcription factors during adenohypophysis development in the chick embryo

• Published in: Developmental dynamics Vol. 239; no. 4; pp. 1197 - 1210
• Main Authors: Parkinson, Nicole, Collins, Michelle M., Dufresne, Lynn, Ryan, Aimee K.
• Format: Journal Article
• Language: English
• Published: New York Wiley‐Liss, Inc 01.04.2010
• Subjects: Animals; Body Patterning - genetics; Body Patterning - physiology; Cell Differentiation - genetics; Cell Differentiation - physiology; Chick Embryo - metabolism; chick pituitary; cLim3; Fgf10; gene expression; Gene Expression Profiling; Gene Expression Regulation, Developmental; Gonadotrophs - cytology; Gonadotrophs - metabolism; Gonadotrophs - physiology; hormones; Intracellular Signaling Peptides and Proteins - genetics; Intracellular Signaling Peptides and Proteins - metabolism; Lactotrophs - cytology; Lactotrophs - metabolism; Lactotrophs - physiology; Melanotrophs - cytology; Melanotrophs - metabolism; Melanotrophs - physiology; Models, Biological; Pituitary Gland, Anterior - embryology; Pituitary Gland, Anterior - metabolism; Pituitary Hormones - genetics; Pituitary Hormones - metabolism; Rathke's pouch; Reverse Transcriptase Polymerase Chain Reaction; RNA, Messenger - analysis; RNA, Messenger - metabolism; SHH; Thyrotrophs - cytology; Thyrotrophs - metabolism; Thyrotrophs - physiology; Transcription Factors - genetics; Transcription Factors - metabolism
• ISSN: 1058-8388; 1097-0177
• DOI: 10.1002/dvdy.22250

The chick embryo is an ideal model to study pituitary cell‐type differentiation. Previous studies describing the temporal appearance of differentiated pituitary cell types in the chick embryo are contradictory. To resolve these controversies, we used RT‐PCR to define the temporal onset and in situ hybridization and immunohistochemistry to define the spatial localization of hormone expression within the pituitary. RT‐PCR detected low levels of Fshβ (gonadotropes) and Pomc (corticotropes, melanotropes) mRNA at E4 and Gh (somatotropes), Prl (lactotropes), and Tshβ (thyrotropes) mRNA at E8. For all hormones, sufficient accumulation of mRNA and/or protein to permit detection by in situ hybridization or immunohistochemistry was observed ∼3 days later and in all cases corresponded to a notable increase in RT‐PCR product. We also describe the expression patterns of signaling (Bmp2, Bmp4, Fgf8, Fgf10, Shh) and transcription factors (Pitx1, Pitx2, cLim3) known to be important for pituitary organogenesis in other model organisms. Developmental Dynamics 239:1197–1210, 2010. © 2010 Wiley‐Liss, Inc.