Cockroaches biosynthesis

Abstract Pheromones are utilized by many insects in a complex chemical communication system. This review will look at the biosynthesis of sex and aggregation pheromones in the model insects, moths, flies, cockroaches, and beetles. The biosynthetic pathways involve altered pathways of normal metabolism of fatty acids and isoprenoids. Endocrine regulation of the biosynthetic pathways will also be reviewed for the model insects. A neuropeptide named pheromone biosynthesis activating neuropeptide regulates sex pheromone biosynthesis in moths. Juvenile hormone regulates pheromone production in the beetles and cockroaches, while 20-hydroxyecdysone regulates pheromone production in the flies. 

Moths, beetles, flies, and cockroaches have received the most attention regarding pheromone biosynthesis because their members contain prominent pest species and in addition are typically easy to rear in the laboratory. However several other insects have been investigated regarding pheromone biosynthesis, most notably the bees and butterflies. 

It was determined that the minimal peptide sequence required to stimulate pheromone biosynthesis was the C-terminal 5 amino acids, FXPRLamide, and that the carboxy terminus needs to be amidated [148,149]. This sequence was also established as the minimal sequence required for myotropic activity in cockroaches [ 150] and induction of embryonic diapause in B. mori [ 151 ]. Crossreactivity of peptides containing the FXPRLamide motif was also established for myotropic, diapause induction, and pheromone biosynthesis [152-154]. Therefore, the common C-terminal FXPRLamide defines this family of peptides. A partial listing of peptides identified to date is shown in Table 1. 

Biosynthesis of methyl branched hydrocarbons of the German cockroach Blattella germanica (L.) (Orthoptera, Blattellidae). Insect Biochemistry 20 149-156. 

Biosynthesis and endocrine control of the production of the German cockroach sex pheromone, 3,1 l-dimethylnonacosan-2-one. Proceedings of the National Academy of Sciences, USA 89 6050-6054. 

Gu, X., Quilici, D., Juarez, P, Blomquist, G. J. and Schal, C. (1995). Biosynthesis of hydrocarbons and contact sex pheromone and their transport by lipophorin in females of the German cockroach (Blattella germanica). Journal of Insect Physiology 41 257-267. 

Schal, C., Fan, Y. and Blomquist, G. J. (2003). Regulation of pheromone biosynthesis, transport, and emission in cockroaches. In Insect Pheromones Biochemistry and Molecular Biology, eds. G. J. Blomquist and R. Vogt, pp. 283-322. New York Academic Press. 

A microsomal FAS was implicated in the biosynthesis of methyl-branched fatty acids and methyl-branched hydrocarbon precursors of the German cockroach contact sex pheromone (Juarez et al., 1992 Gu et al., 1993). A microsomal FAS present in the epidermal tissues of the housefly is responsible for methyl-branched fatty acid production (Blomquist et al., 1994). The housefly microsomal and soluble FASs were purified to homogeneity (Gu et al., 1997) and the microsomal FAS was shown to preferentially use methylmalonyl-CoA in comparison to the soluble FAS. GC-MS analyses showed that the methyl-branching positions of the methyl-branched fatty acids of the housefly were in positions consistent with their role as precursors of the methyl-branched hydrocarbons. 

Chase J., Jurenka R. J., Schal C., Halamkar P. P. and Blomquist G. J. (1990) Biosynthesis of methyl branched hydrocarbons in the German cockroach Blattella germanica (L.) (Qrthoptera, Blattellidae). Insect Biochem. 20, 149-156. 

Gu P, Welch W. H. and Blomquist G. J. (1993) Methyl-branched fatty acid biosynthesis in the German cockroach, Blattella germanica kinetic studies comparing a microsomal and soluble fatty acid synthetases. Insect Biochem. Mol. Biol. 23, 263-271. 

Regulation of pheromone biosynthesis, transport, and emission in cockroaches... 

Figure 10.1 Metabolic pathways for the biosynthesis of 3,11-dimethylnonacosan-2-one and related sex pheromone components of the female contact sex pheromone of the German cockroach, Blattella germanica.

Chiang A.-S. and Schal C. (1994) Cyclic volumetric changes in corpus allatum cells in relation to juvenile hormone biosynthesis during ovarian cycles in cockroaches. Arch. Insect Biochem. Physiol. 27, 53-64. 

Gadot M., Chiang A.-S., Burns E. L. and Schal C. (1991) Cyclic juvenile hormone biosynthesis in the cockroach, Blattella germanica Effects of ovariectomy and corpus allatum denervation. Gen. Comp. Endocrinol. 82, 163-171. 

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