Identification and Characterization of Developmentally Regulated Components of the Stress Axis in Petromyzon Marinus
type: CreativeWork
description: Genes resembling elements of the Corticotropin releasing hormone (CRH) receptor-ligand system (CRH system) have been identified in invertebrate species and suggest the CRH system has existed, in some form, for approximately a billion years. It is theorized that vertebrates inherited components of the CRH system from an invertebrate ancestor. The association of the CRH system with the stress response, however, is specific to vertebrate species and theorized to have accompanied the development of hypothalamic pituitary (HP) axes, specifically the HP interrenal (HPI) axis in fish. A functional HPI axis has recently been suggested in the lamprey species Petromyzon marinus, a member of the ancient vertebrate superclass agnatha, by identification of pituitary and inter-renal components corticotrophin (ACTH) and 11- deoxycortisol respectively. This study, however, is the first to identify the hypothalamic components, specifically the CRH system, of the HPI. In P. marinus the expression of six CRH system genes, including three hormones, CRH A, CRH B and UCN III-like; two receptors, CRH Rα and CRH Rβ; and a binding protein, CRH BP, are identified by PCR and in silico methodologies. Analysis of the P. marinus CRH system genes appear to support the occurance of the Agnathan superclass prior to a theorized second vertebrate whole genome duplication (WGD) event. This is supported by the P. marinus CRH hormones appearing to represent two of the four vertebrate CRH family paralogues; CRH A and B both being orthologous to vertebrate CRH, and UCN III-like being orthologous to vertebrate UCN III. Additionally, neither CRH Rα nor CRH Rβ, while identified as distinct from one another and related to other vertebrate receptors, were phylogenetically indistinguishable as either ii type 1 or 2. This suggests, the two P. marinus CRH receptor genes identified appear type 1 or 2. This suggests, the two P. marinus CRH receptor genes identified appear to have arisen out of a lamprey specific du…
abstract: Genes resembling elements of the Corticotropin releasing hormone (CRH) receptor-ligand system (CRH system) have been identified in invertebrate species and suggest the CRH system has existed, in some form, for approximately a billion years. It is theorized that vertebrates inherited components of the CRH system from an invertebrate ancestor. The association of the CRH system with the stress response, however, is specific to vertebrate species and theorized to have accompanied the development of hypothalamic pituitary (HP) axes, specifically the HP interrenal (HPI) axis in fish. A functional HPI axis has recently been suggested in the lamprey species Petromyzon marinus, a member of the ancient vertebrate superclass agnatha, by identification of pituitary and inter-renal components corticotrophin (ACTH) and 11- deoxycortisol respectively. This study, however, is the first to identify the hypothalamic components, specifically the CRH system, of the HPI. In P. marinus the expression of six CRH system genes, including three hormones, CRH A, CRH B and UCN III-like; two receptors, CRH Rα and CRH Rβ; and a binding protein, CRH BP, are identified by PCR and in silico methodologies. Analysis of the P. marinus CRH system genes appear to support the occurance of the Agnathan superclass prior to a theorized second vertebrate whole genome duplication (WGD) event. This is supported by the P. marinus CRH hormones appearing to represent two of the four vertebrate CRH family paralogues; CRH A and B both being orthologous to vertebrate CRH, and UCN III-like being orthologous to vertebrate UCN III. Additionally, neither CRH Rα nor CRH Rβ, while identified as distinct from one another and related to other vertebrate receptors, were phylogenetically indistinguishable as either ii type 1 or 2. This suggests, the two P. marinus CRH receptor genes identified appear type 1 or 2. This suggests, the two P. marinus CRH receptor genes identified appear to have arisen out of a lamprey specific du…
author: Endsin, Matthew Joel
language: en
date published: 2013-01
date modified: 2026-07-24T04:03:45Z
provider: University of Regina
publisher: Networked Digital Library of Theses and Dissertations
type: WebPage
source organization: Faculty of Graduate Studies and Research, University of Regina

PropertyValue
property ID: Handle
value: https://hdl.handle.net/10294/3817

PropertyValue
property ID: DOI
value: 10.82465/4773