title: Comparative study of the primary cilia in thyrocytes of adult mammals.
abstract: Since their discovery in different human tissues by Zimmermann in 1898, primary cilia have been found in the vast majority of cell types in vertebrates. Primary cilia are considered to be cellular antennae that occupy an ideal cellular location for the interpretation of information both from the environment and from other cells. To date, in mammalian thyroid gland, primary cilia have been found in the thyrocytes of humans and dogs (fetuses and adults) and in rat embryos. The present study investigated whether the existence of this organelle in follicular cells is a general event in the postnatal thyroid gland of different mammals, using both immunolabeling by immunofluorescence and electron microscopy. Furthermore, we aimed to analyse the presence of primary cilia in various thyroid cell lines. According to our results, primary cilia are present in the adult thyroid gland of most mammal species we studied (human, pig, guinea pig and rabbit), usually as a single copy per follicular cell. Strikingly, they were not found in rat or mouse thyroid tissues. Similarly, cilia were also observed in all human thyroid cell lines tested, both normal and neoplastic follicular cells, but not in cultured thyrocytes of rat origin. We hypothesize that primary cilia could be involved in the regulation of normal thyroid function through specific signaling pathways. Nevertheless, further studies are needed to shed light on the permanence of these organelles in the thyroid gland of most species during postnatal life.
authors.affiliation: Department of Normal and Pathological Cytology and Histology, University of Seville, School of Medicine, Seville, Spain.
authors.forename: J C
authors.initials: JC
authors.lastname: Utrilla
authors.affiliation: Department of Normal and Pathological Cytology and Histology, University of Seville, School of Medicine, Seville, Spain.
authors.forename: F
authors.initials: F
authors.lastname: Gordillo-Martínez
authors.affiliation: Department of Normal and Pathological Cytology and Histology, University of Seville, School of Medicine, Seville, Spain.
authors.forename: A
authors.initials: A
authors.lastname: Gómez-Pascual
authors.affiliation: Department of Normal and Pathological Cytology and Histology, University of Seville, School of Medicine, Seville, Spain.
authors.forename: J M
authors.initials: JM
authors.lastname: Fernández-Santos
authors.affiliation: Department of Normal and Pathological Cytology and Histology, University of Seville, School of Medicine, Seville, Spain.
authors.forename: C
authors.initials: C
authors.lastname: Garnacho
authors.affiliation: Department of Normal and Pathological Cytology and Histology, University of Seville, School of Medicine, Seville, Spain.
authors.forename: V
authors.initials: V
authors.lastname: Vázquez-Román
authors.affiliation: Department of Normal and Pathological Cytology and Histology, University of Seville, School of Medicine, Seville, Spain.
authors.forename: J
authors.initials: J
authors.lastname: Morillo-Bernal
authors.affiliation: Department of Normal and Pathological Cytology and Histology, University of Seville, School of Medicine, Seville, Spain.
authors.forename: R
authors.initials: R
authors.lastname: García-Marín
authors.affiliation: Endocrine Surgery Unit of 'Virgen Macarena' University Hospital, Seville, Spain.
authors.forename: A
authors.initials: A
authors.lastname: Jiménez-García
authors.affiliation: Department of Normal and Pathological Cytology and Histology, University of Seville, School of Medicine, Seville, Spain.
authors.forename: I
authors.initials: I
authors.lastname: Martín-Lacave
mesh_terms: D000818:Animals; D002478:Cells, Cultured; D002923:Cilia / Q000648:ultrastructure*; D004285:Dogs; D006168:Guinea Pigs; D006801:Humans; D051379:Mice; D008854:Microscopy, Electron; D011817:Rabbits; D051381:Rats; D015398:Signal Transduction; D013552:Swine; D013961:Thyroid Gland / Q000166:cytology* / Q000378:metabolism
keywords: follicular cells; mammals; primary cilia; thyroid gland