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Zebrafish pit1 mutants lack three pituitary cell types and develop severe dwarfism

, : Zebrafish pit1 mutants lack three pituitary cell types and develop severe dwarfism. Molecular Endocrinology 18(5): 1196-1209

The Pou domain transcription factor Pit-1 is required for lineage determination and cellular commitment processes during mammalian adenohypophysis development. Here we report the cloning and mutational analysis of a pit1 homolog from zebrafish. Compared with mouse, zebrafish pit1 starts to be expressed at a much earlier stage of adenohypophysis development. However, as in the mouse, expression is restricted to a subset of pituitary cell types, excluding proopiomelanocortin (pomc)-expressing cells (corticotropes, melanotropes) and possibly gonadotropes. We could identify two N-ethyl-N-nitrosourea-induced zebrafish pit1 null mutants. Most mutants die during larval stages, whereas survivors develop severe dwarfism. Mutant larvae lack lactotropes, somatotropes, and thyrotropes, although the adenohypophysis is of normal size, without any sign of increased apoptosis rates. Instead, mutant embryos initiate ectopic expression of pomc in pit1-positive cells, leading to an expansion of the Pomc lineage. Similarly, the number of gonadotropes seems increased, as indicated by the expression of gsualpha, a marker for thyrotropes and gonadotropes. In pit1 mutants, the total number of gsualpha-positive cells is normal despite the loss of gsualpha and tshbeta coexpressing cells. Together, these data suggest a transfating of the Pit1 lineage to the Pomc and possibly the gonadotroph lineages in the mutant, and a pomc- and gonadotropin-repressive role of Pit1 during normal zebrafish development. This is different from mouse, for which a repressive role of Pit-1 has only been reported for the gonadotropin Lhbeta, but not for Pomc. In sum, our data point to both conserved and class-specific aspects of Pit1 function during pituitary development in different vertebrate species.


PMID: 14988429

DOI: 10.1210/me.2003-0377

Other references

Fulton, L.M.; Carlson, M.J.; Coghill, J.M.; Ott, L.E.; West, M.L.; Panoskaltsis-Mortari, A.; Littman, D.R.; Blazar, B.R.; Serody, J.S., 2012: Attenuation of acute graft-versus-host disease in the absence of the transcription factor RORγt. Graft-versus-host disease (GVHD) remains the most significant complication after allogeneic stem cell transplantation. Previously, acute GVHD had been considered to be mediated predominantly by Th1-polarized T cells. Recently, investigators have i...

Jurczok, F., 1966: Cystometric studies with benzilic acid-(N,N-dimethyl-2-hydroxymethylpiperidinium)estermethylsulfate. Arzneimittel-Forschung 16(8): 935-936

Cooper, W.A., 1989: Hand scoop for food, such as ice cream. The scoop has a bowl, a handle, a scraper within the bowl for separating scooped food from the bowl, and drive means for effecting movement of the scraper. The handle comprises an elongated member bent back upon itself to define a pivot point, and...

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Busch, S.; Jensen, T.H.; Chushkin, Y.; Fluerasu, A., 2008: Dynamics in shear flow studied by X-ray Photon Correlation Spectroscopy. X-ray Photon Correlation Spectroscopy was used to measure the diffusive dynamics of colloidal particles in a shear flow. The results presented here show how the intensity autocorrelation functions measure both the diffusive dynamics of the particl...

Maddock, W.G.; Bell, J.L.; Tremaine, M.J., 1949: Gastro-intestinal Gas: Observations on Belching: During Anesthesia and Operations, Rapid Passage, and During Pyelography. Annals of Surgery 130(3): 512-535

Mito M.; Ebata H.; Onishi T.; Kusano M.; Ono M., 1977: Survival of hepatocytes transplanted into the spleens of rats and dog. European Surgical Research 9(SUPPL 1): 166

Johnson, A.P., 2011: Measuring mental deterioration by the differential test score method. American Journal of Mental Deficiency 51(3): 389-389

Dokov V.K.; Timmermans L., 1970: Effect of certain antibiotics on spermatogenesis in the rat. Comptes Rendus des Seances de la Societe de Biologie et de ses Filiales 163(12): 2767-2769

Dahleen, L.; Rines, H.; Stuthman, D., 1991: Avenin banding pattern variation in tissue culture-derived oat lines. Plant tissue culture generates genetic variation in crop plants. Biochemical variation from culture has not been examined in oat (Avena sativa L.) regenerants. The objectives of this study were to examine avenin (prolamine) variation in R5 generat...