ZFIN ID: ZDB-PUB-080616-4
Notch signaling regulates endocrine cell specification in the zebrafish anterior pituitary
Dutta, S., Dietrich, J.E., Westerfield, M., and Varga, Z.M.
Date: 2008
Source: Developmental Biology   319(2): 248-257 (Journal)
Registered Authors: Dutta, Sunit, Varga, Zoltan M., Westerfield, Monte
Keywords: Adenohypophysis, Cell differentiation, Cranial, DAPT, Delta, Hormone, Notch, Organogenesis, Patterning, Placode
MeSH Terms:
  • Animals
  • Cell Differentiation/physiology
  • Embryo, Nonmammalian/physiology
  • Embryonic Development
  • Gene Expression Regulation, Developmental
  • Immunohistochemistry
  • In Situ Hybridization
  • Pituitary Gland, Anterior/cytology*
  • Pituitary Gland, Anterior/enzymology
  • Pituitary Gland, Anterior/physiology*
  • RNA, Messenger/genetics
  • Receptors, Notch/genetics*
  • Signal Transduction
  • Zebrafish/genetics
  • Zebrafish Proteins/genetics*
PubMed: 18534570 Full text @ Dev. Biol.
The vertebrate pituitary gland is a key endocrine control organ that contains six distinct hormone secreting cell types. In this study, we analyzed the role of direct cell-to-cell Delta-Notch signaling in zebrafish anterior pituitary cell type specification. We demonstrate that initial formation of the anterior pituitary placode is independent of Notch signaling. Later however, loss of Notch signaling in mindbomb (mib) mutant embryos or by DAPT treatment leads to increased numbers of lactotropes and loss of corticotropes in the anterior pars distalis (APD), increased number of thyrotropes and loss of somatotrope cell types in the posterior pars distalis (PPD), and fewer melanotropes in the posterior region of the adenohypophysis, the pars intermedia (PI). Conversely, Notch gain of function leads to the opposite result, loss of lactotrope and thyrotrope cell specification, and an increased number of corticotropes, melanotropes, and gonadotropes in the pituitary. Our results suggest that Notch acts on placodal cells, presumably as a permissive signal, to regulate progenitor cell specification to hormone secreting cell types. We propose that Notch mediated lateral inhibition regulates the relative numbers of specified hormone cell types in the three pituitary subdomains.