Atlantic halibut growth hormone: Structure and plasma levels of sexually mature males and females during photoperiod-regulated annual cycles

  • Einarsdottir I
  • Sakata S
  • Thrandur Björnsson B
  • 26

    Readers

    Mendeley users who have this article in their library.
  • 16

    Citations

    Citations of this article.

Abstract

The main objectives of this study were to obtain the amino acid sequence of Atlantic halibut (Hippoglossus hippoglossus) growth hormone (hhGH) and compare it with other teleost species, to establish a radioimmunoassay to assess plasma hhGH levels and thus to gain information about possible biological functions and regulation by photoperiod. The hhGH gene was cloned and its amino acid sequence deduced from the cDNA. The mature hhGH protein consists of 186 amino acids. Comparison with other flatfish species as well as a species from a different order, the pufferfish, reveals that the sequence similarities of the mature hhGH with that of the barfin flounder, the Japanese flounder, the sole and the pufferfish are 99.5, 81.7, 74.2, and 65.2%, respectively. The sequence similarities appear to correctly reflect the gross phylogenetic relationships among these teleost species. A specific GH-RIA was developed for measurements of Atlantic halibut GH levels. Assessment of plasma GH levels in adult halibut revealed large gender differences, with GH levels frequently being an order of magnitude higher in males than females. The mean (±SEM) plasma GH for males kept on normal annual photoperiod were 25:2 ± 6:11ngml-1and for females were 5:14 ± 1:94ngml-1. It appears likely that plasma growth hormone levels in Atlantic halibut can be inversely correlated to growth and metabolism. Shifting of the annual photoperiod cycles demonstrated that photoperiod in not a regulator of plasma GH levels in the Atlantic halibut, but further research is needed to assess whether GH plays a role in the reproduction of this marine teleost species. © 2002 Elsevier Science (USA). All rights reserved.

Author-supplied keywords

  • Amino acid sequence
  • Atlantic halibut
  • Growth hormone
  • Photoperiod
  • Reproduction

Get free article suggestions today

Mendeley saves you time finding and organizing research

Sign up here
Already have an account ?Sign in

Find this document

Authors

  • Ingibjörg Eir Einarsdottir

  • Shusaku Sakata

  • Björn Thrandur Björnsson

Cite this document

Choose a citation style from the tabs below

Save time finding and organizing research with Mendeley

Sign up for free