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    • Article

      Isolation and characterization of vitellin from the ovary of Penaeus monodon 

      ET Quinitio, A Hara, K Yamauchi & A Fuji - Invertebrate Reproduction and Development, 1990 - International Society of Invertebrate Reproduction and Development
      Female-specific protein (FSP, vitellogenin) in Penaeus monodon hemolymph and its related ovarian protein (vitellin, lipovitellin) were identified and characterized using electrophoretical and immunological procedures. The purification of vitellin from mature ovaries was carried out using hydroxylapatite and Sepharose 6B columns. Results indicated that there are two proteins specifically existing in the hemolymph of the mature female which are immunologically identical to ovarian protein. These are absent in the male. The isolated vitellin has a molecular weight of approximately 540 kDa and is composed of 4 major (polypeptide) subunits, 74, 83, 104 and 168 kDa and 1 minor (polypeptide) subunit, 90 kDa. The purified protein stained positively with periodic acid-Schiff and Sudan black B and thus is a glycolipoprotein.

      Results of double immunodiffusion demonstrate the cross-reactivity of P. monodon vitellin antiserum with the ovarian extract from mature females of Penaeus indicus, Penaeus merguiensis and Penaeus semisulcatus, but not with Pandalus kessleri, indicating that there is no antigenic difference at species level in Penaeidae.
    • Article

      Profiles of progesterone- and estradiol-like substances in the hemolymph of female Pandalus kessleri during an annual reproductive cycle 

      ET Quinitio, K Yamauchi, A Hara & A Fuji - General and Comparative Endocrinology, 1991 - Elsevier
      The changes in GSI and HSI of Pandalus kessleri were monitored during an annual reproductive cycle. GSI reached a peak when ovaries were composed of yolky oocytes and decreased sharply during the spawning season. HSI followed a similar pattern. The changes in the concentrations of progesterone- and estradiol-17β-like substances in the hemolypmh were also investigated. Progesterone levels increased at the onset of vitellogenesis and decreased during vitellogenesis. In contrast, estradiol concentrations rose during the peak of vitellogenesis and dropped after the release of mature eggs from the gonad.