Biosynthesis and endocrine control of the production of the German cockroach sex pheromone 3,11-dimethylnonacosan-2-one.

Abstract

The biosynthesis and endocrine regulation of sex pheromone production in the female German cockroach (Blattela germanica) were determined. Radio-TLC and radio-GLC were used to demonstrate the metabolism of 3,11-dimethylnonacosane, a major cuticular lipid component, to the corresponding alkan-2-ol and methyl ketone. [11,12-3H2J-3,11-Dimethylnonacosan-2-ol was efficiently metabolized to the methyl ketone, and radio-GLC showed that the methyl ketone product from both experiments was coeluted with a methyl ketone standard. A comparison ofthe metabolism of the labeled dimethylalkane and dimethylalkan-2-ol by age and sex showed that both males and females from day 1 through day 9 after adult emergence readily metabolized the alcohol to the corresponding methyl ketone, whereas only females of 5-9 days postemergence efficiently converted the labeled dimethylalkane to the corresponding methyl ketone. Application of the juvenile hormone analog hydroprene induced significant increases in the conversion of the labeled hydrocarbon to the methyl ketone in starved adult females as well as in females fed a protein-free diet, conditions under which endogenous juvenile hormone biosynthesis is nearly undetectable. These data show that the methyl ketone sex pheromone is formed by the hydroxylation and oxidation of the 3,11-dimethylalkane at the 2 position, show that the age-and sex-specific step in this process is the conversion of 3,11-dimethylnonacosane to 3,11-dimethylnonacosan-2-ol, and provide evidence that juvenile hormone regulates sex pheromone production in the German cockroach.

Patterns of biosynthesis and accumulation of hydrocarbons and contact sex pheromone in the female german cockroach, Blattella germanica

“…We hypothesize that JH regulates pheromone production by increasing the activity of the enzyme system (presumably involving a polysubstrate monooxygenase) that converts the dimethylalkane to the corresponding dimethyl ketone. This is supported by sex-and stage-specific metabolism of [11,12-3H2J3,1 1-dimethylnonacosane to the corresponding alkan-2-01 as the penultimate step in pheromone synthesis in adult females [15]. Conversely, [11,12-3H213,1 ldimethylnonacosan-2-01 is efficiently and nonspecrfically metabolized to methyl ketone in both males and females, suggesting that the last step in pheromone synthesis is not under endocrine control.…”

Endocrine regulation of de novo aggregation pheromone biosynthesis in the pine engraver, Ips pini (Say) (Coleoptera: Scolytidae)

“…Pheromone biosynthesis is regulated by pheromone-biosynthesisactivating-neuropeptide (PBAN) (reviewed in Raina, 1993Raina, , 1997 in most lepidopterans; ecdysone in some dipterans (reviewed in Blomquist et al, 1987Blomquist et al, , 1992; and juvenile hormone (JH) in coleopterans (reviewed in Vanderwel, 1994), some blattodeans (Schal et al, 1990;Chase et al, 1992), and some lepidopterans (Cusson and McNeil, 1989). Studies of scolytids have shown that pheromone biosynthesis in the presence or absence of host monoterpene precursors and without pre-feeding is stimulated by topical treatment with exogenous juvenile hormone III (JH III) or JH analogs (JHAs) Hughes and Renwick, 1977a, b;Harring, 1978;Renwick and Dickens, 1979;Bridges, 1982;Conn et al, 1984;Chen et al, 1988).…”

Identification of cuticular lipids eliciting interspecific courtship in the German cockroach, Blattella germanica

“…The major peak in the hydrocarbon fraction of the cuticular extracts of B. orientalis contains 11-and 13-methylheptacosane (Lockey and Dularay 1986). Based on the biosynthetic pathway of the contact sex pheromone in the German cockroach (Chase et al 1992), we predicted that the largest peak in the 2% ether fraction (ketone fraction) of B. orientalis would contain 11-and/or 13-methylheptacosan-2-one or 15-and 17-methylheptacosan-2-one (depending on which side of the molecule the carbonyl group is located). MS data provided some support for this prediction: m/z 408 indicates the molecular weight of a 27 carbon chain with a single methyl branch, m/z 390 (M + -18) indicates the loss of H 2 O, a typical fragment in carbonylcontaining compounds.…”

“…The female contact sex pheromone consists of three 29-carbon components and a homologous series of 27-carbon components (Nishida and Fukami 1983;Schal et al 1990;Eliyahu et al 2008). The 29-carbon dimethyl ketone (and probably the 27-carbon homolog as well) is derived from insertion of a C-2 carbonyl into the preformed 3,11-dimethylalkane (Chase et al 1992), and a similar mechanism might give rise to the 29-hydroxy-, 29-oxo-, 27-hydroxy-, and 27-oxo-pheromone components. The epicuticular surface of B. germanica contains numerous methyl-branched alkanes in homologous series of 27-and 29-carbon chains (Augustynowicz et al 1987;Carlson and Brenner 1988;Jurenka et al 1989).…”