ISSN:
1432-0878
Keywords:
Pituitary gland
;
Gonadotropin
;
Subunits
;
Gonadotropes
;
Immunocytochemistry
;
Immunoblotting
;
Oncorhynchus mykiss (Teleostei)
Source:
Springer Online Journal Archives 1860-2000
Topics:
Biology
,
Medicine
Notes:
Abstract Salmon gonadotropin (GTH II) is a heterodimeric glycoprotein hormone (α and IIβ subunits), serving as a maturational GTH, and is produced in a specific gonadotropic cell-type (GTH II-cells) containing small granules and large globules. In trout GTH II-cells, double immunolabeling for the α- and IIβ-subunits shows that colocalization of the α- and IIβ-immunolabeling is confined to the small granules, indicating storage of functional GTH II. On the other hand, α-immunolabeling is absent in the large globules, even though IIβ labeling is abundant throughout the period of seasonal gametogenesis. The α-specific antiserum recognizes the intact α-subunit as well as the reduced and deglycosylated α-subunits by immunoblotting. These results indicate that an accumulation of the IIβ-subunit is specifically generated in the large globules of these cells. In fact, with sexual maturity, the quantity of IIβ-subunits becomes elevated in the trout pituitary due to a marked increase in GTH II-cells containing many large globules. However, the derivation and function of the large globules and the fate of their contained IIβ-subunits remains unknown.
Type of Medium:
Electronic Resource
URL:
http://dx.doi.org/10.1007/BF00300695
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