Pheromones biosynthesis in moths

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. 

The role of the nervous system in pheromone biosynthesis in moths is not clearly understood. Christensen and co-workers [208-211] proposed that the neurotransmitter octopamine may be involved as an intermediate messenger during the stimulation of sex pheromone production in H. virescens. These workers suggested that octopamine was involved in the regulation of pheromone production and that PBAN s role lies in the stimulation of octopamine release at nerve endings. However, contradicting results concerning octopa-mine-stimulated pheromone production were reported in the same species as well as other moth species [163,172,212-214]. 

Jurenka R. A. and Roelofs W. L. (1989) Characterization of the acetyltransferase involved in pheromone biosynthesis in moths specificity for the Z isomer in Tortricidae. Insect Biochem. 19, 639-644. 

In this chapter we will review the current state of knowledge about how pheromone production is regulated in female moths. Discussion of PBAN identification and localization within the nervous system will be followed by how PBAN acts to stimulate pheromone biosynthesis. The final major topic will be a discussion of mediators and inhibitors of PBAN action. A considerable amount of information has accumulated with regard to regulation of pheromone biosynthesis in moths since Pheromone Biochemistry (Prestwich and Blomquist, 1987) was first published, and this chapter is not all inclusive. Further information can also be obtained in several reviews (Raina, 1993 Jurenka, 1996 Teal et al., 1996 Rafaeli et al., 1997b Raina, 1997 Rafaeli, 2002). 

The role of the nervous system in pheromone biosynthesis in moths is not clearly understood. In several moths, including L. dispar (Tang et al., 1987 Thyagaraja and Raina, 1994), H. virescens (Christensen et al., 1991), S. littoralis (Marco et al., 1996), and M. brassicae (Iglesias et al., 1998), an intact VNC was reported as necessary for pheromone biosynthesis by intact moths. On the other hand, in many species (even in some of those mentioned above) isolated pheromone glands responded to applied synthetic PBAN in an in vitro culture. 

Altstein M., Ben-Aziz O., Daniel S., Schefler I., Zeltser I. and Gilon C. (1999a) Backbone cyclic peptide antagonists, derived from the insect pheromone biosynthesis activating neuropeptide, inhibit sex pheromone biosynthesis in moths. J. Biol. Chem. 274,17573-17579. 

Jurenka R. A. (1996) Signal transduction in the stimulation of sex pheromone biosynthesis in moths. Arch. Insect Biochem. Physiol. 33, 245-258. 

Rafaeli A. (2002) Neuroendocrine control of pheromone biosynthesis in moths. Int. Rev. Cytol. 213, 49-91. 

Sex pheromone biosynthesis in moths is affected by a variety of exogenous and endogenous factors such as temperature, photoperiod, host... 

Sex pheromone biosynthesis in many moth species is controlled by a cerebral neuropeptide, so-called PBAN. PBAN is a 33 amino acid C-terminally amidated neuropeptide that is produced by neuroendocrine cells of the subesophageal ganglion (SEG), Studies of the regulation of sex pheromone biosynthesis in moths have revealed that this function can be elicited by additional neuropeptides, all of which share the common C-terminal pentapeptide [99-103]. All of these peptides were found to contain the signature C-terminal sequence and have been designated the PK/PBAN family. The PK/PBAN family is a multifunctional family of peptides that plays a major role in the physiology of insects. In addition to their ability to stimulate sex pheromone biosynthesis in moths, they... 

PBAN binding to a receptor results in signal transduction events to stimulate the pheromone biosynthetic pathway (Fig. 5). Receptor activation results in the influx of extracellular calcium and has been demonstrated in a number of moths [163-168]. The increase in cytosolic calcium can directly stimulate pheromone biosynthesis in some moths [165-168] or it will stimulate the production of cAMP [169,170]. So far cAMP has only been implicated in signal... 

Bell, T. W Boppre, M., Schneider, D. and Meinwald, J. (1984). Stereochemical course of pheromone biosynthesis in the arctiid moth, Creatonotos transiens. Experientia 40 713-714. 

Boppre, M. and Schneider, D. (1985). Pyrrolizidine alkaloids quantitatively regulate both scent organ morphogenesis and pheromone biosynthesis in male Creatonotos moths (Lepidoptera Arctiidae). Journal of Comparative Physiology A 157 569-577. 

Another technique that is utilized to help ensure that label is incorporated into the pheromone is to apply the precursor at the same time as pheromone biosynthesis activating neuropeptide (PBAN). PBAN is a peptide hormone that regulates pheromone biosynthesis in most, but not all, moths. So, first it must be demonstrated that PBAN regulates pheromone production. In the case of the cabbage looper,... 

Arsequell G., Fabrias G. and Camps F. (1990) Sex pheromone biosynthesis in the processionary moth Thaumetopoeapityocampa by delta-13 desaturation. Arch. Insect Biochem. Physiol. 14, 47-56. 

Foster S. P. (2000) Fatty acyl pheromone analogue-containing lipids and their roles in sex pheromone biosynthesis in the lightbrown apple moth, Epiphyaspostvittana (Walker). J. Insect Physiol. 47, 433 443. 

Wu W. Q., Zhu J. W., Millar J. and Lofstedt C. (1998) A comparative study of sex pheromone biosynthesis in two strains of the turnip moth, Agrotis segetum, producing different ratios of sex pheromone components. Insect Biochem. Mol. Biol. 28, 895-900. 

Bjostad L. B. and Roelofs W. L. (1986) Sex pheromone biosynthesis in the red banded leafroller moth studied by mass-labeling with stable isotopes and analysis with mass spectrometry. J. Chem. Ecol. 12, 431-450. 

PBAN regulation of pheromone biosynthesis in female moths... 

Arima R., Takahara K., Kadoshima T., Numazaki F., Ando T., Uchiyama M., Nagasawa H., KitamuraA. and Suzuki A. (1991) Hormonal regulation of pheromone biosynthesis in the silkworm moth, Bombyx mori (Lepidoptera Bombycidae). Appl. Entomol. Zool. 26, 137-147. 

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