YOLK PROTEIN PRODUCTION IN THE MARINE SHRIMP PENAEUS VANNAMEI

Abstract

ABSTRACT Yolk production of the marine shrimp Penaeus vannamei was measured using an antibody to a subunit of the yolk protein complex. The effects of unilateral eyestalk ablation on protein synthesis of the hepatopancreas and ovary were measured in vitro. Initially, activity in both tissues increased; 21 days after eyestalk ablatior activity levels in both tissues returned to levels equal to or lower than preablation levels. The yolk protein content of the tissues increased shortly after eyestalk ablation and reached a maximum of 8% in ovarian tissue, but less than 1% in the hepatopancreas. Yolk proteins in the hemolymph were detected using an enzymelinked immunoassay. Both intact controls and eyestalk-ablated shrimp had as much as 1 mg/ ml yolk protein in the hemolymph during ovarian maturation. Newly released shrimp eggs had an average of 53 ng yolk protein per egg. Eyestalk ablation induced a rapid increase in protein synthesis in both ovary and hepatopancreas. During ovarian maturation, yolk proteins were transported through the hemolymph in this marine shrimp.