AROMATIC HEXAMERIN SUBUNIT FROM ADULT FEMALE COCKROACHES (BLABERUS-DISCOIDALIS) - MOLECULAR-CLONING, SUPPRESSION BY JUVENILE-HORMONE, AND EVOLUTIONARY PERSPECTIVES

In an effort to identify several polypeptides that are strongly suppre ssed by juvenile hormone (JH) in fat body of adult female Blaberus dis coidalis cockroaches, we have cloned a cDNA representing a polypeptide member of the hexamerin family of arthropod serum proteins. The deduc ed primary translation product consists of a 17-residue signal peptide and a mature protein of 716 residues (86.1KDa) composed of 21% tyrosi ne plus phenylalanine. The latter property leads us to assign the name arylphorin to the cockroach protein. In pairwise comparisons Blaberus arylphorin (BAr) has 30-39% positional identity with other insect hex amerins and with cheliceratan and crustacean hemocyanins. In multiple alignment with 21 arthropod hexamerins there are 18 invariant residues . We present the profile of BAr mRNA as correlated to the reproductive cycle, where BAr accumulates dramatically between cycles of JH-depend ent vitellogenesis.