Expression and distribution of the glucocorticoid receptor DlGR1 in the teleost Dicentrarchus labrax brain

Abstract

Cortisol is the main corticosteroid secreted by the interrenal cells of the head kidney and it exerts a role in mantaining the omeostatic status in fish. In teleosts its effects are mediated through intracellular receptors expressed in several tissues, that are ligand-dependent transcription factors by binding to specific tissue DNNA sequences. In Dicentrarchus labrax we previously cloned and sequenced a glucocorticoid receptor, DlGR1, isolated from leukocytes of peritoneal cavity. In this work we showed mRNNA expression and tissue immunohistochemical localization of brain DlGR1 by in situ hybridization assays, with a riboprobe with DlGR1 cDNNA trascriptional activation domain, and by immunohistochemical methods, using a specific antibody for a selected sequence of the receptor transcriptional domain. The mRNNA and the protein are expressed in pyramidal cells of the optic lobe and in the small globular neurons of the diencephalon.