The Israeli Journal of Aquaculture - Bamidgeh 54(2), 2002
The Annual Dan Popper Symposium


REGULATION OF PROTEIN SYNTHESIS
IN SHRIMP OVARIES BY NEUROHORMONES


Jean-Christophe Avarre¹, Morad Khayat¹, Regina Michelis¹,4, Hiromishi Nagasawa², Alisa Tietz³, Esther Lubzens¹ *

1 Israel Oceanographic and Limnological Research, P.O.Box 8030, Haifa 81080, Israel
2 Department of Applied Biological Chemistry, The University of Tokyo, Bunkyo-ku, Tokyo 113, Japan
3 Department of Neurobiochemistry, Tel Aviv University, Tel Aviv 66978, Israel
4 Eliachar Research Laboratory, Western Galilee Hospital, Nahariya 22100, Israel


Abstract

Mature penaeid oocytes possess extracellular cortical rods that contain precursor proteins of the jelly layer. The jelly layer forms a protective layer around eggs immediately after spawning and dissipates following the assembly of the hatching envelope. Among those precursors is the shrimp ovarian peritrophin protein (SOP). The temporal pattern of mRNA expression and protein synthesis of SOP in Penaeus semisulcatus ovaries was followed during vitellogenesis and the regulation by sinus gland extracts (SGE) and crustacean hyperglycemic hormone (CHH) family peptides was evaluated.
SOP transcripts were detected in all stages of ovarian development but were more abundant in pre-vitellogenic ovaries than in other stages. SOP was synthesized in ovarian explant fragments that were removed from vitellogenic ovaries and incubated in vitro, but synthesis was not detected in explants that were collected from pre-vitellogenic ovaries. De novo synthesis of SOP was inhibited by P.semisulcatus SGE and by CHH-family peptides that were purified from P.japonicus sinus glands .Sinus gland extracts, however, did not affect the steady state levels of SOP transcripts at any stage of ovarian development. These results suggest that SGE regulate SOP synthesis at the post-transcriptional level.

*Corresponding author: E-mail: esther@ocean.org.il

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