The intrinsic synthesis of juvenile hormone-III diol by locust corpora allata in vitro.

Juvenile hormone (JH)-III 10-11-diol is intrinsically synthesized and released from the corpora allata (CA) of adult locust females in vitro, together with JH-III. JH-III synthesis is preferentially stimulated and diol production only slightly enhanced, by cerebral locust allatotropin. The identification of JH-III diol is based on: similar ratio of incorporation of 14C/3H from radiolabelled [2-14C]acetate and [methyl-3H]methionine, to that of JH-III; similar chromatographic properties to those of synthetic diol on an RP-18 column eluted with acetonitrile, and similar chromatographic properties of acetylated derivatives; mass spectrometric analysis of derivatives and fragmentation products. Exogenous radiolabelled JH-III is not degraded during incubation with locust CA in vitro, corroborating the endogenous production of JH-III diol. Allatal diol formation may be an additional mechanism for the control of JH-III levels in locusts, preceding release into the hemolymph.