Cyanoprotein: Developmental stage,sex and diapause-dependent expression,and synthesis regulation by juvenile hormone in the bean bug,Riptortus clavatus

Cyanoprotein (CP) synthesis was studied in nymphal and nondiapause adult, diapause adult, and juvenile hormone (JH) treated adult bean bugs, Riptortus clavatus. Hemolymph collected from bugs injected with ³⁵S]-methionine was analyzed by native polyacrylamide gel electrophoresis (PAGE) and fluorography, and CP synthesis was also determined quantitatively by rocket immunoelectrophoresis of hemolymph and counting. In the nymphal stages synthesis of CP-1, 2, 3, and 4 (with CP-4 synthesis predominant) reached a maximum at mid-instar and was not detected at each ecdysis, so that the synthetic activity of CPs changed cyclically in each instar. During the nymphal stages CP synthesis showed the same pattern and level in both females and males, and both diapause and nondiapause oriented bugs. In the adult stage, however, CP synthesis differed in the two sexes and nondiapause or diapause conditions. In nondiapause males CP synthesis was not detected in the adult, but in nondiapause females CP (only CP-1) was synthesized through the reproductive stages. CP-1 accumulated in the egg yolk together with vitellogenin. In diapause adults (both females and males) CP-1 to 4 were synthesized at a very low rate for over 2 months and accumulated in the hemolymph. JH or JH analog (JHA) methoprene and also long day condition, which terminate diapause, switched the main CP synthesis CP-4 to CP-1 in females. CP synthesis in diapause males stopped after JH(A) treatment. The activities of CP synthesis, thus, changed in developmental stages, sexes, and diapause. This is an excellent system for study of specific gene expression and switching controlled by insect hormones and sex. © 1992 Wiley-Liss, Inc.