title: Anatomical and functional gonadotrope networks in the teleost pituitary.
abstract: Mammalian pituitaries exhibit a high degree of intercellular coordination; this enables them to mount large-scale coordinated responses to various physiological stimuli. This type of communication has not been adequately demonstrated in teleost pituitaries, which exhibit direct hypothalamic innervation and expression of luteinizing hormone (LH) and follicle-stimulating hormone (FSH) in distinct cell types. We found that in two fish species, namely tilapia and zebrafish, LH cells exhibit close cell-cell contacts and form a continuous network throughout the gland. FSH cells were more loosely distributed but maintained some degree of cell-cell contact by virtue of cytoplasmic processes. These anatomical differences also manifest themselves at the functional level as evidenced by the effect of gap-junction uncouplers on gonadotropin release. These substances abolished the LH response to gonadotropin-releasing hormone stimulation but did not affect the FSH response to the same stimuli. Dye transfer between neighboring LH cells provides further evidence for functional coupling. The two gonadotropins were also found to be differently packaged within their corresponding cell types. Our findings highlight the evolutionary origin of pituitary cell networks and demonstrate how the different levels of cell-cell coordination within the LH and FSH cell populations are reflected in their distinct secretion patterns.
authors.affiliation: Department of Animal Sciences, The Robert H. Smith Faculty of Agriculture, Food and Environment, The Hebrew University of Jerusalem, Rehovot 76100, Israel.|CNRS, UMR-5203, Institut de Génomique Fonctionnelle, F-34000 Montpellier, France.|INSERM, U661, F-34000 Montpellier, France.|Universités de Montpellier 1 &2, UMR-5203, F-34000 Montpellier, France.
authors.forename: Matan
authors.initials: M
authors.lastname: Golan
authors.affiliation: CNRS, UMR-5203, Institut de Génomique Fonctionnelle, F-34000 Montpellier, France.|INSERM, U661, F-34000 Montpellier, France.|Universités de Montpellier 1 &2, UMR-5203, F-34000 Montpellier, France.
authors.forename: Agnés O
authors.initials: AO
authors.lastname: Martin
authors.affiliation: CNRS, UMR-5203, Institut de Génomique Fonctionnelle, F-34000 Montpellier, France.|INSERM, U661, F-34000 Montpellier, France.|Universités de Montpellier 1 &2, UMR-5203, F-34000 Montpellier, France.
authors.forename: Patrice
authors.initials: P
authors.lastname: Mollard
authors.affiliation: Department of Animal Sciences, The Robert H. Smith Faculty of Agriculture, Food and Environment, The Hebrew University of Jerusalem, Rehovot 76100, Israel.
authors.forename: Berta
authors.initials: B
authors.lastname: Levavi-Sivan
mesh_terms: D000818:Animals; D005075:Biological Evolution; D002450:Cell Communication / Q000187:drug effects; D005260:Female; D005456:Fluorescent Dyes / Q000378:metabolism; D005640:Follicle Stimulating Hormone / Q000235:genetics / Q000378:metabolism; D017629:Gap Junctions / Q000187:drug effects / Q000378:metabolism* / Q000648:ultrastructure; D005786:Gene Expression Regulation; D052681:Gonadotrophs / Q000187:drug effects / Q000378:metabolism* / Q000648:ultrastructure; D007987:Gonadotropin-Releasing Hormone / Q000235:genetics / Q000378:metabolism; D007031:Hypothalamus / Q000187:drug effects / Q000378:metabolism* / Q000648:ultrastructure; D007546:Isoquinolines / Q000378:metabolism; D007986:Luteinizing Hormone / Q000235:genetics / Q000378:metabolism; D008469:Meclofenamic Acid / Q000494:pharmacology; D015398:Signal Transduction; D017210:Tilapia / Q000033:anatomy & histology / Q000502:physiology*; D015027:Zebrafish / Q000033:anatomy & histology / Q000502:physiology*
chemical_list: D005456:Fluorescent Dyes; D007546:Isoquinolines; D007987:Gonadotropin-Releasing Hormone; D008469:Meclofenamic Acid; D007986:Luteinizing Hormone; D005640:Follicle Stimulating Hormone; C017475:lucifer yellow