title: Hes1 and Hes5 control the progenitor pool, intermediate lobe specification, and posterior lobe formation in the pituitary development.
abstract: The pituitary gland is composed of two distinct entities: the adenohypophysis, including the anterior and intermediate lobes, and the neurohypophysis, known as the posterior lobe. This critical endocrine organ is essential for homeostasis, metabolism, reproduction, and growth. The pituitary development requires the control of proliferation and differentiation of progenitor cells. Although multiple signaling molecules and transcription factors are required for the proper pituitary development, the mechanisms that regulate the fate of progenitor cells remain to be elucidated. Hes genes, known as Notch effectors, play a crucial role in specifying cellular fates during the development of various tissues and organs. Here, we report that mice deficient for Hes1 and Hes5 display severe pituitary hypoplasia caused by accelerated differentiation of progenitor cells. In addition, this hypoplastic pituitary gland (adenohypophysis) lacks the intermediate lobe and exhibits the features of the anterior lobe only. Hes1 and Hes5 double-mutant mice also lack the neurohypophysis (the posterior lobe), probably due to incomplete evagination of the diencephalon. Thus, Hes genes control not only maintenance of progenitor cells but also intermediate vs. anterior lobe specification during the adenohypophysis development. Hes genes are also essential for the formation of the neurohypophysis.
authors.affiliation: Department of Neurosurgery, Kyoto University Graduate School of Medicine, 54 Kawahara-cho, Shogoin, Sakyo-ku, Kyoto 606-8507, Japan.
authors.forename: Aya
authors.initials: A
authors.lastname: Kita
authors.forename: Itaru
authors.initials: I
authors.lastname: Imayoshi
authors.forename: Masato
authors.initials: M
authors.lastname: Hojo
authors.forename: Masashi
authors.initials: M
authors.lastname: Kitagawa
authors.forename: Hiroshi
authors.initials: H
authors.lastname: Kokubu
authors.forename: Ryosuke
authors.initials: R
authors.lastname: Ohsawa
authors.forename: Toshiyuki
authors.initials: T
authors.lastname: Ohtsuka
authors.forename: Ryoichiro
authors.initials: R
authors.lastname: Kageyama
authors.forename: Nobuo
authors.initials: N
authors.lastname: Hashimoto
mesh_terms: D000818:Animals; D051792:Basic Helix-Loop-Helix Proteins / Q000032:analysis / Q000235:genetics / Q000378:metabolism*; D002454:Cell Differentiation / Q000235:genetics; D018398:Homeodomain Proteins / Q000032:analysis / Q000235:genetics / Q000378:metabolism*; D051379:Mice; D008817:Mice, Mutant Strains; D038081:Organogenesis / Q000235:genetics*; D010904:Pituitary Gland, Posterior / Q000002:abnormalities* / Q000254:growth & development* / Q000378:metabolism; D012097:Repressor Proteins / Q000032:analysis / Q000235:genetics / Q000378:metabolism*; D013234:Stem Cells / Q000166:cytology / Q000378:metabolism / Q000502:physiology*; D000072056:Transcription Factor HES-1
chemical_list: D051792:Basic Helix-Loop-Helix Proteins; D018398:Homeodomain Proteins; D012097:Repressor Proteins; D000072056:Transcription Factor HES-1; C489734:Hes1 protein, mouse; C489685:Hes5 protein, mouse