Prestwich / Blomquist Pheromone Biochemistry

1. Auflage 2014
ISBN: 978-1-4832-1937-0
Verlag: Elsevier Science & Techn.
Format: EPUB
Kopierschutz: Adobe DRM (»Systemvoraussetzungen)

E-Book, Englisch, 586 Seiten

Pheromone Biochemistry covers chapters on Lepidoptera, ticks, flies, beetles, and even vertebrate olfactory biochemistry. The book discusses pheromone production and its regulation in female insects; as well as reception, perception, and degradation of pheromones by male insects. The text then describes the pheromone biosynthesis and its regulation and the reception and catabolism of pheromones. Researchers in the areas of chemistry, biochemistry, entomology, neurobiology, molecular biology, enzymology, morphology, behavior, and ecology will find the book useful.

Autoren/Hrsg.

Prestwich, Glenn D.

Blomquist, Gary J.

Leseproben

1 Relationship of Structure and Function to Biochemistry in Insect Pheromone Systems
J.H. TUMLINSON and P.E.A. TEAL,     Insect Attractants, Behavior, and Basic Biology Research Laboratory, Agricultural Research Service, U.S. Department of Agriculture, Gainesville, Florida 32604 Publisher Summary
This chapter discusses the relationship of structure and function to biochemistry in insect pheromone systems. It presents molecular studies in pheromone biosynthesis, perception, and catabolism. A wide range of compounds have been identified as insect pheromone components. While carbon, hydrogen, and oxygen are the usual atoms incorporated into these molecules, nitrogenated and chlorinated compounds have also been identified. Usually, small molecules are used for communication when rapid dispersal of the signal is needed, while larger, less volatile compounds tend to function in attraction and stimulation when prolonged exposure is necessary. The former case is exemplified by 4-methyl-3-heptanone, used by numerous species of myrmicine ants as an alarm pheromone. The latter is illustrated by numerous lepidopteran sex pheromone components that are generally between 10 and 24 carbons in length and are much less volatile than the alarm pheromone. In addition to the different molecular sizes that reflect behavioral functions, pheromone structures vary greatly between different orders of insects. Generic themes of structural type exist within groups as is evidenced by the use of the same or structurally related compounds by many species of the same genus. These themes are the result of the development of common biosynthetic pathways with differences in blend ratios and components being the result of minor permutations in the enzymatic steps involved. I INTRODUCTION
Chemical cues are major sources of information used by most insects to interpret environmental stimuli. This reliance on chemical stimuli undoubtedly stems from the development of chemosensory organs and cells early in evolutionary history, perhaps even before the development of light-sensitive organs (Snodgrass, 1926). Broadly speaking, these chemical stimuli are categorized as semiochemicals. They function as pheromones when used for intraspecific communication. When used at the interspecific level, they are termed kairomones when the species responding to the chemical message benefits and allomones when the species emitting the signal gains some advantage over the receiving organism. There is considerable overlap between these classes, and often the same compounds serve both intra- and interspecific functions. Therefore, in order to elucidate the roles of individual semiochemicals it is necessary to study all aspects of the communication system from biosynthesis of the compounds to the perception and integration of the compounds by all of the organisms responding. Of the three classes of semiochemicals mentioned above, pheromones are the most extensively studied. Although all insect orders use pheromones in communication, the highly social Hymenoptera and Isoptera have developed the most complex and sophisticated pheromone systems. In fact, Blum (1974) suggests a strong evolutionary relationship between the development of insect societies and diversification of pheromone communication. Among subsocial insects, pheromones have been shown to play major roles in (1) the initiation of gregarious behavior during group oviposition among certain mosquitoes (Hudson and Mclintock, 1967) and the desert locust Schistocerca gregaria (Forsk.) (Norris, 1963); (2) the formation of aggregations at food sites, particularly among scolytid beetles (Birch, 1984) and Drosophila species (Bartelt et al., 1985); (3) dispersal behavior among generally gregarious species during predator attack (Nault and Phelan, 1984); (4) the synchronization of gamete maturity among species exhibiting aggregative behaviors (Blum, 1974); and (5) mate attraction among species that maintain a solitary life style. According to Inscoe (1977), conspecific attractancy among lepidopteran species has been known since 1690, when John Ray reported several male Biston betularia (L.) flying around a caged female. This knowledge of the attractive capacity of female Lepidoptera also was used by such great naturalists as Fabré for collection of rare specimens; the procedure used was essentially the same as that of Ray (Kettlewell, 1946; Inscoe, 1977). The use of live females for population monitoring of the gypsy moth, Lymantria dispar (L.), began in 1914, but by 1920 the females had been replaced by crude abdominal tip extracts that remained active for longer periods than females (Collins and Potts, 1932). Attempts to isolate the chemical components of lepidopteran sex attractants also began in the 1920s. Unfortunately, the methods then available for chemical analysis were not adequate, requiring large sample quantities and necessitating continuous rearing of large numbers of insects. As a consequence, little headway was made. The first sex pheromone identified was that of Bombyx mori (L.), the silkworm moth, by Butenandt et al. (1959). The elucidation of bombykol [(E,Z)-10,12-hexadecadien-1-ol] required 20 years and 500,000 female abdomens. Subsequent to the identification of “bombykol,” considerable emphasis was placed on the identification of pheromone components of pest Lepidoptera, and, in 1966, (Z)-7-dodecenyl acetate was identified as the sex pheromone of the cabbage looper moth (Berger, 1966). Following this, single components of the pheromones of a number of noctuid and tortricid moths were identified. This led to the “magic bullet” theory of pheromone communication, which hypothesized that every insect species used a single compound for pheromone communication and that each species was isolated from closely related species by differences in the functionality or number and geometry of double bonds within the pheromone molecule. This hypothesis was generally accepted by many researchers working on Lepidoptera until about 1970. However, early work on bark beetles by Silverstein et al. (1966) in which three terpenes, (S)-(–)-ipsenol (I), (S)-(+)-ipsdienol (II), and (S)-(+)-cis-verbenol (III), were identified as a synergistic pheromone blend for Ips paraconfusus Lanier, indicated that multicomponent pheromones were used by Coleoptera. This has since been shown to be true for most insects, and now single-component pheromones are the exception rather than the rule. Our knowledge of the chemistry, behavior, physiology, and biochemistry of insect communication systems has increased dramatically over the past 25 years. Early studies were aimed at two different goals. The first was development of a basic knowledge about the biological aspects of pheromone communication, as is indicated by the early work of Shorey and co-workers (e.g., Shorey, 1964; Shorey and Gaston, 1965). The second area was the identification and synthesis of pheromones based on simple bioassays. The bioassays used for these studies tended to rely on single behaviors, such as flight or clasper extension, of groups of insects and failed to monitor observations of the whole range of reproductive behaviors exhibited by individual males. Additionally, the chromatographic and spectroscopic instrumentation available in the 1960s was incapable of resolving complex isomeric mixtures or of detecting minor components present in only nanogram amounts. Thus, usually only the components present in greatest quantity were identified. This is illustrated by the identification of (Z)-7-dodecenyl acetate as the sex pheromone of the cabbage looper moth (Berger, 1966). While this compound is an effective attractant for males for this species, the insects do not exhibit the entire range of behaviors performed in response to females. It was not until 1984 that Bjostad et al. (1984) and Linn et al. (1984) accurately defined the complete pheromone blend of this insect. The additional components identified by Bjostad et al. (1984) are present in very small amounts and were not found until studies on biosynthesis identified the precursors of the additional components. This demonstrates the need for studies on all aspects of semiochemical-mediated biology. The next step in the evolution of studies on pheromone communication came with the development and common use of electrophysiological techniques including the electroantennogram and single cell recording. These studies aided the identification process greatly and, in conjunction with electron microscopic studies, also formed the foundations on which our theories of pheromone perception are based. These advances coupled with tremendous improvements in analytical instrumentation (Heath and Tumlinson, 1984) and the use of flight tunnel studies (see Fig. 1, Section III) to sequentially analyze the responses of individual insects have led us to the realization that insects use complex chemical systems, rather than single unrelated signals, for communication. Frequently there is considerable overlap in signals, particularly among closely related species.
Fig. 1 Typical responses of male noctuid moths to the...