2005 Fiscal Year Final Research Report Summary
Identification of adenohypophysial hormones from the hagfish pituitary gland and its evolutional implication
| Project/Area Number |
15570047
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| Research Category |
Grant-in-Aid for Scientific Research (C)
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| Allocation Type | Single-year Grants |
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| Section | 一般 |
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| Research Field |
Morphology/Structure
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| Research Institution | Niigata University |
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Principal Investigator |
NOZAKI Masumi Niigata University, Institute of Science and Technology, Professor, 自然科学系, 教授 (70136232)
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| Project Period (FY) |
2003 – 2005
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| Keywords | Hagfish / Pituitary gland / Adenohypophysial hormones / Gonadotropin / Reproduction / Immunohistochemistry |
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| Research Abstract |
The present study aimed to elucidate the pituitary system of hagfish by means of immunohistochemical and molecular biological techniques. Adenohypophysial cell types were studied in the pituitaries of the Atlantic and the Pacific hagfish, using antisera to tetrapod and fish pituitary hormones. Three different types of immunoreactive cells were detected in the adenohypophysis, which appeared to correspond with gonadotropin (GTH)-like, growth hormone (GH)-like and adrenocorticotropin (ACTH)-like cells. In the subsequent study, the relationship between the amount of GTH-like material and gonadal conditions was examined in the brown hagfish (Paramyxine atami), one of the Pacific hagfish. Immunoreactive GTH-like material was heavily accumulated in adults with developing gonads, whereas it was not or only weakly accumulated in juveniles or adults without developing gonads. Following intraperitoneal administration of estradiol benzoate in juvenile animals of P.atami, the intensities of GTH-like material in the adenohypophysis increased significantly when compared to those of controls. cDNAs of both α- and β-subunits of GTH have been cloned from the pituitary gland of P.atami (Nozaki et al., unpublished). The deduced amino acid sequence of the hagfish GTHα shows 39-44% identity to α-subunits of gnathostome glycoproteins, and the hagfish GTHβ shows similar identity (30-43%) with gnathostome LHβ,FSHβ, and TSHβ. These results indicated the presence of GTH in the hagfish pituitary gland.
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Research Products
(14 results)
