title: Flatfish metamorphosis: a hypothalamic independent process?
abstract: Anuran and flatfish metamorphosis are tightly regulated by thyroid hormones that are the necessary and sufficient factors that drive this developmental event. In the present study whole mount in situ hybridization (WISH) and quantitative PCR in sole are used to explore the central regulation of flatfish metamorphosis. Central regulation of the thyroid in vertebrates is mediated by the hypothalamus-pituitary-thyroid (HPT) axis. Teleosts diverge from other vertebrates as hypothalamic regulation in the HPT axis is proposed to be through hypothalamic inhibition although the regulatory factor remains enigmatic. The dynamics of the HPT axis during sole metamorphosis revealed integration between the activity of the thyrotrophes in the pituitary and the thyroid follicles. No evidence was found supporting a role for thyroid releasing hormone (trh) or corticotrophin releasing hormone (crh) in hypothalamic control of TH production during sole metamorphosis. Intriguingly the results of the present study suggest that neither hypothalamic trh nor crh expression changes during sole metamorphosis and raises questions about the role of these factors and the hypothalamus in regulation of thyrotrophs.
authors.affiliation: Comparative and Molecular Endocrinology Group, Marine Science Centre (CCMAR), Universidade do Algarve, Faro 8005-139, Portugal. Electronic address: macampinho@ualg.pt.
authors.forename: Marco A
authors.initials: MA
authors.lastname: Campinho
authors.affiliation: Comparative and Molecular Endocrinology Group, Marine Science Centre (CCMAR), Universidade do Algarve, Faro 8005-139, Portugal.
authors.forename: Nadia
authors.initials: N
authors.lastname: Silva
authors.affiliation: Comparative and Molecular Endocrinology Group, Marine Science Centre (CCMAR), Universidade do Algarve, Faro 8005-139, Portugal; IFAPA Centro El Toruño, El Puerto de Santa Maria, Cadiz 11500, Spain.
authors.forename: Javier
authors.initials: J
authors.lastname: Roman-Padilla
authors.affiliation: IFAPA Centro El Toruño, El Puerto de Santa Maria, Cadiz 11500, Spain.
authors.forename: Marian
authors.initials: M
authors.lastname: Ponce
authors.affiliation: IFAPA Centro El Toruño, El Puerto de Santa Maria, Cadiz 11500, Spain.
authors.forename: Manuel
authors.initials: M
authors.lastname: Manchado
authors.affiliation: Comparative and Molecular Endocrinology Group, Marine Science Centre (CCMAR), Universidade do Algarve, Faro 8005-139, Portugal.
authors.forename: Deborah M
authors.initials: DM
authors.lastname: Power
mesh_terms: D000818:Animals; D003346:Corticotropin-Releasing Hormone / Q000235:genetics / Q000378:metabolism; D029941:Fish Proteins / Q000235:genetics* / Q000378:metabolism*; D005412:Flatfishes / Q000254:growth & development* / Q000378:metabolism; D007031:Hypothalamus / Q000378:metabolism*; D017403:In Situ Hybridization; D008675:Metamorphosis, Biological; D010902:Pituitary Gland / Q000378:metabolism; D016133:Polymerase Chain Reaction; D013954:Thyroglobulin / Q000235:genetics / Q000378:metabolism; D013961:Thyroid Gland / Q000378:metabolism*; D013973:Thyrotropin-Releasing Hormone / Q000235:genetics / Q000378:metabolism
chemical_list: D029941:Fish Proteins; D013973:Thyrotropin-Releasing Hormone; D013954:Thyroglobulin; D003346:Corticotropin-Releasing Hormone
keywords: Axis; Flatfish; Hypothalamus; Metamorphosis; Pituitary; Thyroid