PROGESTERONE-RECEPTOR IN THE REPRODUCTIVE-SYSTEM OF THE FEMALE OF OCTOPUS-VULGARIS - CHARACTERIZATION AND IMMUNOLOCALIZATION

In this study for the first time we have characterized a progesterone receptor in the reproductive system of the female of Octopus vulgaris. Scatchard analysis revealed that one binding component with high affi nity and low capacity for the ligand was present only in the nuclear e xtract. Competition experiments showed that the progesterone receptor was strictly specific for progesterone. DNA-cellulose binding and DEAE -Sephacel both confirmed the presence of one H-3-progesterone binding component which eluted at a salt concentration of 0.14 +/- 0.05 M NaCl and 0.15 +/- 0.05 M NaCl respectively By using monoclonal antibodies against chicken progesterone receptor (subunits A and B), we have loca lized on Western Blot one band of about 70 kDa. Immunoreactivity for p rogesterone binding molecules has been localized in the nuclei of the follicle cells of the ovary, of the proximal portion of the oviduct an d of the outer region of the nidimental gland. These data, taken toget her, provide evidence that in Octopus vulgaris the progesterone recept or has biochemical and immunohistochemical characteristics resembling those of progesterone receptor in vertebrates. Mol. Reprod. Dev. 50:45 1-460, 1998. (C) 1998 Wiley-Liss, Inc.