Flatfish metamorphosis: a hypothalamic independent process?
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.
['Campinho|Marco A|MA|', 'Silva|Nadia|N|', 'Roman-Padilla|Javier|J|', 'Ponce|Marian|M|', 'Manchado|Manuel|M|', 'Power|Deborah M|DM|']
D000818:Animals D003346:Corticotropin-Releasing Hormone D029941:Fish Proteins D005412:Flatfishes D007031:Hypothalamus D017403:In Situ Hybridization D008675:Metamorphosis, Biological D010902:Pituitary Gland D016133:Polymerase Chain Reaction D013954:Thyroglobulin D013961:Thyroid Gland D013973:Thyrotropin-Releasing Hormone
Flatfish Metamorphosis Thyroid Axis Pituitary Hypothalamus