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Drosophila Cuticular Hydrocarbons Revisited: Mating Status Alters Cuticular Profiles  [PDF]
Claude Everaerts,Jean-Pierre Farine,Matthew Cobb,Jean-Fran?ois Ferveur
PLOS ONE , 2012, DOI: 10.1371/journal.pone.0009607
Abstract: Most living organisms use pheromones for inter-individual communication. In Drosophila melanogaster flies, several pheromones perceived either by contact/at a short distance (cuticular hydrocarbons, CHs), or at a longer distance (cis-vaccenyl acetate, cVA), affect courtship and mating behaviours. However, it has not previously been possible to precisely identify all potential pheromonal compounds and simultaneously monitor their variation on a time scale. To overcome this limitation, we combined Solid Phase Micro-Extraction with gas-chromatography coupled with mass-spectrometry. This allowed us (i) to identify 59 cuticular compounds, including 17 new CHs; (ii) to precisely quantify the amount of each compound that could be detected by another fly, and (iii) to measure the variation of these substances as a function of aging and mating. Sex-specific variation appeared with age, while mating affected cuticular compounds in both sexes with three possible patterns: variation was (i) reciprocal in the two sexes, suggesting a passive mechanical transfer during mating, (ii) parallel in both sexes, such as for cVA which strikingly appeared during mating, or (iii) unilateral, presumably as a result of sexual interaction. We provide a complete reassessment of all Drosophila CHs and suggest that the chemical conversation between male and female flies is far more complex than is generally accepted. We conclude that focusing on individual compounds will not provide a satisfactory understanding of the evolution and function of chemical communication in Drosophila.
Dietary Effects on Cuticular Hydrocarbons and Sexual Attractiveness in Drosophila  [PDF]
Tatyana Y. Fedina, Tsung-Han Kuo, Klaus Dreisewerd, Herman A. Dierick, Joanne Y. Yew, Scott D. Pletcher
PLOS ONE , 2012, DOI: 10.1371/journal.pone.0049799
Abstract: Dietary composition is known to have profound effects on many aspects of animal physiology, including lifespan, general health, and reproductive potential. We have previously shown that aging and insulin signaling significantly influence the composition and sexual attractiveness of Drosophila melanogaster female cuticular hydrocarbons (CHCs), some of which are known to be sex pheromones. Because diet is intimately linked to aging and to the activity of nutrient-sensing pathways, we asked how diet affects female CHCs and attractiveness. Here we report consistent and significant effects of diet composition on female CHC profiles across ages, with dietary yeast and sugar driving CHC changes in opposite directions. Surprisingly, however, we found no evidence that these changes affect female attractiveness. Multivariate comparisons among responses of CHC profiles to diet, aging, and insulin signaling suggest that diet may alter the levels of some CHCs in a way that results in profiles that are more attractive while simultaneously altering other CHCs in a way that makes them less attractive. For example, changes in short-chain CHCs induced by a high-yeast diet phenocopy changes caused by aging and by decreased insulin signaling, both of which result in less attractive females. On the other hand, changes in long-chain CHCs in response to the same diet result in levels that are comparable to those observed in attractive young females and females with increased insulin signaling. The effects of a high-sugar diet tend in the opposite direction, as levels of short-chain CHCs resemble those in attractive females with increased insulin signaling and changes in long-chain CHCs are similar to those caused by decreased insulin signaling. Together, these data suggest that diet-dependent changes in female CHCs may be sending conflicting messages to males.
Cuticular hydrocarbons of Chagas disease vectors in Mexico
Juárez, M Patricia;Carlson, David A;Salazar Schettino, Paz María;Mijailovsky, Sergio;Rojas, Gloria;
Memórias do Instituto Oswaldo Cruz , 2002, DOI: 10.1590/S0074-02762002000600012
Abstract: capillary gas-liquid chromatography was used to analyse the cuticular hydrocarbons of three triatomine species, triatoma dimidiata, t. barberi and dipetalogaster maxima, domestic vectors of chagas disease in mexico. mixtures of saturated hydrocarbons of straight and methyl-branched chains were characteristic of the three species, but quantitatively different. major methylbranched components mostly corresponded to different saturated isomers of monomethyl, dimethyl and trimethyl branched hydrocarbons ranging from 29 to 39 carbon backbones. sex-dependant, quantitative differences in certain hydrocarbons were apparent in t. dimidiata.
Cuticular hydrocarbons of Chagas disease vectors in Mexico  [cached]
Juárez M Patricia,Carlson David A,Salazar Schettino Paz María,Mijailovsky Sergio
Memórias do Instituto Oswaldo Cruz , 2002,
Abstract: Capillary gas-liquid chromatography was used to analyse the cuticular hydrocarbons of three triatomine species, Triatoma dimidiata, T. barberi and Dipetalogaster maxima, domestic vectors of Chagas disease in Mexico. Mixtures of saturated hydrocarbons of straight and methyl-branched chains were characteristic of the three species, but quantitatively different. Major methylbranched components mostly corresponded to different saturated isomers of monomethyl, dimethyl and trimethyl branched hydrocarbons ranging from 29 to 39 carbon backbones. Sex-dependant, quantitative differences in certain hydrocarbons were apparent in T. dimidiata.
A Model-Based Analysis of Chemical and Temporal Patterns of Cuticular Hydrocarbons in Male Drosophila melanogaster  [PDF]
Clement Kent, Reza Azanchi, Ben Smith, Adrienne Chu, Joel Levine
PLOS ONE , 2007, DOI: 10.1371/journal.pone.0000962
Abstract: Drosophila Cuticular Hydrocarbons (CH) influence courtship behaviour, mating, aggregation, oviposition, and resistance to desiccation. We measured levels of 24 different CH compounds of individual male D. melanogaster hourly under a variety of environmental (LD/DD) conditions. Using a model-based analysis of CH variation, we developed an improved normalization method for CH data, and show that CH compounds have reproducible cyclic within-day temporal patterns of expression which differ between LD and DD conditions. Multivariate clustering of expression patterns identified 5 clusters of co-expressed compounds with common chemical characteristics. Turnover rate estimates suggest CH production may be a significant metabolic cost. Male cuticular hydrocarbon expression is a dynamic trait influenced by light and time of day; since abundant hydrocarbons affect male sexual behavior, males may present different pheromonal profiles at different times and under different conditions.
Sexual selection on cuticular hydrocarbons in the Australian field cricket, Teleogryllus oceanicus
Melissa L Thomas, Leigh W Simmons
BMC Evolutionary Biology , 2009, DOI: 10.1186/1471-2148-9-162
Abstract: We found that all three measures of male attractiveness generated sexual selection on male cuticular hydrocarbons, however there were differences in the form and intensity of selection among these three measures. Mating success was the only measure of attractiveness that imposed both univariate linear and quadratic selection on cuticular hydrocarbons. Although we found that all three attractiveness measures generated nonlinear selection, again only mating success was found to exert statistically significant stabilizing selection.This study shows that sexual selection plays an important role in the evolution of male cuticular hydrocarbon signals.It is common in natural populations for individuals of one sex, usually the female, to prefer certain phenotypic trait values over others in their choice of mates. Female preferences for male sexual signals are responsible for a spectacular array of phenotypic diversity found in the natural world, driving the evolution of exaggerated traits such as colouration [1], conspicuous ornaments [2,3], and song [4,5]. Females have also been found to base their choice of mate on pheromone signals. Although less well studied, pheromone signals are subject to the same kinds of natural and sexual selective forces that shape visual and auditory signals [6]. However, our understanding of the processes driving the evolution of pheromones is significantly less well developed.Cuticular hydrocarbons are chemical compounds found on the cuticle of most terrestrial arthropods. These compounds have been studied extensively for their role as signals in mate and species recognition, and ecology [7,8]. Cuticular hydrocarbons are highly sexually dimorphic in a range of species, with many of the compounds present in one sex but absent in the other, while shared compounds often differ quantitatively between the sexes [see [9] for review]. Such sexual dimorphism is expected to result from sex-specific selection. Despite the large number of species that di
Variation in cuticular hydrocarbons among strains of the Anopheles gambiae sensu stricto by analysis of cuticular hydrocarbons using gas liquid chromatography of larvae
Anyanwu, Greg I;Molyneux, David H;Phillips, Angela;
Memórias do Instituto Oswaldo Cruz , 2000, DOI: 10.1590/S0074-02762000000300003
Abstract: cuticular hydrocarbons of larvae of individual strains of the anopheles gambiae sensu stricto were investigated using gas liquid chromatography. biomedical discriminant analysis involving multivariate statistics suggests that there was clear hydrocarbon difference between the gambian(g3), the nigerian (16css and, its malathion resistant substrain, refma) and the tanzanian (kwa) strains. the high degree of segregation (95%) in hydrocarbons among the four strains investigated indicates that further analysis is needed to enable understanding of hydrocarbon variation in samples of an. gambiae especially from areas where these populations co-exist.
Variation in cuticular hydrocarbons among strains of the Anopheles gambiae sensu stricto by analysis of cuticular hydrocarbons using gas liquid chromatography of larvae  [cached]
Anyanwu Greg I,Molyneux David H,Phillips Angela
Memórias do Instituto Oswaldo Cruz , 2000,
Abstract: Cuticular hydrocarbons of larvae of individual strains of the Anopheles gambiae sensu stricto were investigated using gas liquid chromatography. Biomedical discriminant analysis involving multivariate statistics suggests that there was clear hydrocarbon difference between the Gambian(G3), the Nigerian (16CSS and, its malathion resistant substrain, REFMA) and the Tanzanian (KWA) strains. The high degree of segregation (95%) in hydrocarbons among the four strains investigated indicates that further analysis is needed to enable understanding of hydrocarbon variation in samples of An. gambiae especially from areas where these populations co-exist.
Simultaneously Hermaphroditic Shrimp Use Lipophilic Cuticular Hydrocarbons as Contact Sex Pheromones  [PDF]
Dong Zhang,John A. Terschak,Maggy A. Harley,Junda Lin,J?rg D. Hardege
PLOS ONE , 2012, DOI: 10.1371/journal.pone.0017720
Abstract: Successful mating is essentially a consequence of making the right choices at the correct time. Animals use specific strategies to gain information about a potential mate, which is then applied to decision-making processes. Amongst the many informative signals, odor cues such as sex pheromones play important ecological roles in coordinating mating behavior, enabling mate and kin recognition, qualifying mate choice, and preventing gene exchange among individuals from different populations and species. Despite overwhelming behavioral evidence, the chemical identity of most cues used in aquatic organisms remains unknown and their impact and omnipresence have not been fully recognized. In many crustaceans, including lobsters and shrimps, reproduction happens through a cascade of events ranging from initial attraction to formation of a mating pair eventually leading to mating. We examined the hypothesis that contact pheromones on the female body surface of the hermaphroditic shrimp Lysmata boggessi are of lipophilic nature, and resemble insect cuticular hydrocarbon contact cues. Via chemical analyses and behavioural assays, we show that newly molted euhermaphrodite-phase shrimp contain a bouquet of odor compounds. Of these, (Z)-9-octadecenamide is the key odor with hexadecanamide and methyl linoleate enhancing the bioactivity of the pheromone blend. Our results show that in aquatic systems lipophilic, cuticular hydrocarbon contact sex pheromones exist; this raises questions on how hydrocarbon contact signals evolved and how widespread these are in the marine environment.
Effectiveness of isopropyl myristate/cyclomethicone D5 solution of removing cuticular hydrocarbons from human head lice (Pediculus humanus capitis)  [cached]
Barnett Eric,Palma Kathleen G,Clayton Bert,Ballard Timothy
BMC Dermatology , 2012, DOI: 10.1186/1471-5945-12-15
Abstract: Background In the treatment of human head lice infestation, healthcare providers are increasingly concerned about lice becoming resistant to existing pesticide treatments. Traditional pesticides, used to control these pests, have a neurological mechanism of action. This publication describes a topical solution with a non-traditional mechanism of action, based on physical disruption of the wax layer that covers the cuticle of the louse exoskeleton. This topical solution has been shown clinically to cure 82% of patients with only a 10-minute treatment time, repeated once after 7 days. All insects, including human head lice, have a wax-covered exoskeleton. This wax, composed of hydrocarbons, provides the insect with protection against water loss and is therefore critical to its survival. When the protective wax is disrupted, water loss becomes uncontrollable and irreversible, leading to dehydration and death. A specific pattern of hydrocarbons has been found in all of the head louse cuticular wax studied. Iso-octane effectively removes these hydrocarbons from human head lice’s cuticular wax. Methods A method of head louse cuticle wax extraction and analysis by gas chromatography was developed. Human head lice (Pediculus humanus capitis) were collected from infested patients and subjected to any of three extraction solvents comprising either the test product or one of two solvents introduced as controls. A gas chromatograph equipped with a flame ionization detector (GC/FID) was used to determine the presence of hydrocarbons in the three head lice extracts. Results In the study reported herein, the test product isopropyl myristate/cyclomethicone D5 (IPM/D5) was shown to perform comparably with iso-octane, effectively extracting the target hydrocarbons from the cuticular wax that coats the human head louse exoskeleton. Conclusions Disruption of the integrity of the insect cuticle by removal of specific hydrocarbons found in the cuticular wax appears to offer a mechanism for killing lice without the likelihood of encountering genetic resistance.
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