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 o f procedures that yielded an apparently pure compound involved ammoniu m sulfate precipitation (20-60% saturation cut), DEAE anion exchange c olumn chromatography, and polyacrylamide gel electrophoresis. The mole cular 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 p olyclonal antibody has been produced against this molecule and used fo r the construction of an immunoaffinity column. A pure JH receptor mol ecule has been isolated from crude fat body homogenates with this affi nity column. The JH receptor is first identified in last instar nymphs and quantitatively increases as the instar progresses towards adult d evelopment. 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 co mpetence to synthesize Vg.