A COMPARATIVE-STUDY OF THE OVARIAN PROTEINS FROM 2 PENAEID SHRIMPS, PENAEUS-SEMISULCATUS DEHAAN AND PENAEUS-VANNAMEI (BOONE)

1. Vitellins (Vts) and two other major ovarian proteins were purified from Penaeus semisulcatus and P. vannamei. The native Vts have similar molecular weights (283-289 kDa) and amino acid composition. SDS-PAGE profiles revealed two major polypeptide subunits for P. semisulcatus and P. vannamei. 2. The high molecular weight cortical crypts protein (CCP) was identified in both species, and an additional major protein (peak A protein) was purified from P. semisulcatus ovaries. 3. The antisera raised against the isolated Vt of each species reacted specifically with native con- and counter-Vt species. No cross-immunoreaction was observed among Vt, CCP and peak A protein antisera. 4. In P. semisulcatus, consistent Vt immunoprofiles were found during oocyte maturation and the purification procedure. Repeating the same immunoreactions in P. vannamei resulted in an inconsistent pattern of the Vt immunoprofiles. This was attributed to structural changes taking place in the Vt during oocyte maturation and not to the specificity of the antisera. 5. Ovarian homogenates of P. semisulcatus and P. vannamei subjected to denatured PAGE reveal stained bands that may represent peptides with similar mobility, one belonging to Vt and another to the protein A peak.