Effects of sex steroids on the mRNA levels of gonadotropin subunits in juvenile and ovariectomized goldfish Carassius auratus.

• KOBAYASHI MAKITO

  Department of Aquatic Bioscience, Graduate School of Agricultural and Life Sciences, The University of Tokyo

• SOHN YOUNG CHANG

  Department of Aquatic Bioscience, Graduate School of Agricultural and Life Sciences, The University of Tokyo

• YOSHIURA YASUTOSHI

  Department of Aquatic Bioscience, Graduate School of Agricultural and Life Sciences, The University of Tokyo

• AIDA KATSUMI

  Department of Aquatic Bioscience, Graduate School of Agricultural and Life Sciences, The University of Tokyo

Abstract

In order to elucidate the regulation of gonadotropin (GTH) gene expression by gonadal sex steroids, the effects of ovariectomy and sex steroid administration on pituitary mRNA levels of GTH subunits were examined in goldfish. Ovariectomy caused a marked increase in GTH Iβ mRNA levels, and steroid hormone replacement (testosterone, T; estradiol-17β, E₂; and 11-ketotestosterone, KT) suppressed the elevated levels in sexually early recrudescent and mature females. Pituitary mRNA levels of α and GTH IIβ were not affected by ovariectomy and steroid hormone treatment. When sex steroids (T, E₂, and KT) were administered to sexually immature juvenile fish, GTH Iβ mRNA levels were suppressed as observed in adult fish. However, GTH IIβ mRNA levels were observed to increase by sex steroids (T and E₂ but not KT) unlike that observed with adult fish. These results indicate that sex steroids exert an inhibitory effect on GTH Iβ mRNA levels from the time goldfish are immature to the time they are mature. However, sex steroids (T and E₂) have a stimulatory effect on GTH IIβ mRNA levels in juvenile goldfish and the effect becomes less pronounced when they become adult.

Journal

• Fisheries science

  Fisheries science 66 (2), 223-231, 2000

  The Japanese Society of Fisheries Science

Keywords

• goldfish
• gonadotropin
• mRNA
• ovariectomy
• sex steroid

Details

• CRID: 1390001204428348288
• NII Article ID: 130003742244
• NII Article ID: 10004857796
• NII Book ID: AA10993718
• DOI: 10.1046/j.1444-2906.2000.00038.x
• COI: 1:CAS:528:DC%2BD3cXjsl2gu78%3D
• ISSN: 14442906
• ISSN: 09199268
• NDL BIB ID: 5381808
• Web Site: https://ndlsearch.ndl.go.jp/books/R000000004-I5381808
• Text Lang: en
• Data Source:
  • JaLC
  • NDL
  • Crossref
  • CiNii Articles
• Abstract License Flag: Disallowed