Pax6 is essential for establishing ventral-dorsal cell boundaries in pituitary gland development.
Pax6, a highly conserved member of the paired homeodomain transcription factor family that plays essential roles in ocular, neural, and pancreatic development and effects asymmetric transient dorsal expression during pituitary development, with its expression extinguished before the ventral --> dorsal appearance of specific cell types. Analysis of pituitary development in the Small eye and Pax6 -/- mouse mutants reveals that the dorsoventral axis of the pituitary gland becomes ventralized, with dorsal extension of the transcriptional determinants of ventral cell types, particularly PFrk. This ventralization is followed by a marked decrease in terminally differentiated dorsal somatotrope and lactotrope cell types and a marked increase in the expression of markers of the ventral thyrotrope cells and SF-1-expressing cells of gonadotrope lineage. We suggest that the transient dorsal expression of Pax6 is essential for establishing a sharp boundary between dorsal and ventral cell types, based on the inhibition of Shh ventral signals.
Kioussi
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Howard Hughes Medical Institute, University of California San Diego, School, Department of Medicine, 9500 Gilman Drive, Cellular and Molecular Medicine Room 345, La Jolla, CA 92093-0648, USA.
O'Connell
S
S
St-Onge
L
L
Treier
M
M
Gleiberman
A S
AS
Gruss
P
P
Rosenfeld
M G
MG
D000818:Animals; D004268:DNA-Binding Proteins / Q000502:physiology*; D005136:Eye Proteins; D013006:Growth Hormone / Q000032:analysis; D053823:Hedgehog Proteins; D018398:Homeodomain Proteins; D051379:Mice; D000071841:PAX6 Transcription Factor; D051761:Paired Box Transcription Factors; D010902:Pituitary Gland / Q000166:cytology / Q000196:embryology*; D011388:Prolactin / Q000032:analysis; D011506:Proteins / Q000502:physiology; D012097:Repressor Proteins; D015534:Trans-Activators
D004268:DNA-Binding Proteins; D005136:Eye Proteins; D053823:Hedgehog Proteins; D018398:Homeodomain Proteins; D000071841:PAX6 Transcription Factor; D051761:Paired Box Transcription Factors; C000605732:Pax6 protein, mouse; D011506:Proteins; D012097:Repressor Proteins; D015534:Trans-Activators; D011388:Prolactin; D013006:Growth Hormone