The juvenile hormone receptor of the cockroach Leucophaea maderae

The juvenile hormone (JH) receptor has been isolated and purified from fat bodies of females and males of Leucophaea maderae. The sequence of procedures that yielded an apparently pure compound involved ammonium sulfate precipitation (20-60% saturation cut), DEAE anion exchange column chromatography, and polyacrylamide gel electrophoresis. The molecular size of the resulting high affinity JH-binding protein is about 64 kDa and is apparently composed of two equal subunits of 32 kDa. A polyclonal antibody has been produced against this molecule and used for the construction of an immunoaffinity column. A pure JH receptor molecule has been isolated from crude fat body homogenates with this affinity column. The JH receptor is first identified in last instar nymphs and quantitatively increases as the instar progresses towards adult development. In penultimate nymphal instars this JH receptor could not be identified and this is correlated with a lack of competence to make vitellogenin (Vg) upon exposure to the JH analog methoprene. Thus, a correlation is seen between the presence of the JH receptor and the competence to synthesize Vg.