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Chemical Signals (chemical + signal)
Selected AbstractsDetection of the Sexual Identity of Conspecifics through Volatile Chemical Signals in a Territorial SalamanderETHOLOGY, Issue 3 2007Benjamin J. Dantzer Territorial red-backed salamanders (Plethodon cinereus) have been shown to use nonvolatile chemical signals in both territorial defense and to convey a variety of information to conspecifics. We investigated whether or not red-backed salamanders could determine the sexual identity of conspecifics through volatile chemical signals, and we explored their use in the context of territorial defense. We exposed male and female red-backed salamanders to four experimental treatments (i.e. filter papers that had been scent marked by male or female conspecifics for 1 and 5 d) and two control treatments (i.e. unscented filter papers for 1 and 5 d tests). The focal salamanders were prevented from physically accessing the scent marked filter papers and, presumably, some of the substrate scent marks had volatile components that were detected and interpreted by the focal salamanders. Both male and female red-backed salamanders spent significantly more time in threat displays when they were exposed to volatile chemical signals from same-sex conspecifics than they did toward similar signals from opposite-sex conspecifics. A similar statistical pattern was observed for the amount of chemosensory sampling exhibited by focal red-backed salamanders. From these results, we infer that red-backed salamanders can determine the sexual identity of conspecifics through volatile chemical signals, some of which may be used in territorial defense. Further, such airborne pheromones may influence the spatial organization of salamander territories on the forest floor. [source] Wilson's Storm Petrels Oceanites oceanicus Recognise the Olfactory Signature of Their MateETHOLOGY, Issue 12 2007Pierre Jouventin Chemical signals in birds have rarely been considered as recognition cues. Nevertheless, recent experiments showed that several petrel species are able to recognize their nest by smell, and in at least one species even their mate. But the use of smell may be different across the petrel species and olfactory nest recognition appears to be dependent on species' breeding biology. To increase our knowledge of individual olfactory recognition in petrels and the relationships between breeding biology and use of smell, we tested Wilson's storm petrels Oceanites oceanicus in Antarctica. In previous experiments, these birds failed to home if rendered anosmic, but the method employed to obtain anosmia (potentially stressing birds) and the fact that they breed in 24-h daylight suggest that they might use visual, rather than olfactory, cues to recognize their nest. Our birds were tested in T-maze experiments where nest odours or partner odours were presented. Wilson's storm petrels preferred odours of their own nest and mate. Results on olfactory nest recognition confirm and complete previous results, viz. anosmic Wilson's storm petrels do not home. Storm petrels olfactory mate recognition suggests that this ability may be widespread in burrowing petrels and implements olfactory nest recognition. [source] Evidence of a rheotactic component in the odour search behaviour of freshwater eelsJOURNAL OF FISH BIOLOGY, Issue 3 2003A. G. Carton The detection of food odour by the freshwater eels, Anguilla australis and Anguilla dieffenbachii released a behavioural response to flow that resulted in direct upstream movement toward the odour source. Changes in various orientation parameters were observed as eels neared the source. Eels had substantially lower swimming velocities and considerably more variable heading and course angles close to the odour source (,0·9 m) than further away (>0·9 m). Observed changes in orientation parameters were primarily due to changes in the behaviour of a searcher following odour loss. Cross-stream movements were initiated when the eel moved beyond the lateral margins of the odour plume. The behavioural switch from odour-conditioned rheotaxis to cross-stream casting following odour loss occurred more frequently close to the odour source where the plume was most narrow. Odour-conditioned rheotaxis enables the searcher to move quickly and efficiently toward the odour source without the need to extract directional information from a highly intermittent and complex chemical signal. [source] Effects of substrate geometry on growth cone behavior and axon branchingDEVELOPMENTAL NEUROBIOLOGY, Issue 11 2006Ginger S. Withers Abstract At the leading edge of a growing axon, the growth cone determines the path the axon takes and also plays a role in the formation of branches, decisions that are regulated by a complex array of chemical signals. Here, we used microfabrication technology to determine whether differences in substrate geometry, independent of changes in substrate chemistry, can modulate growth cone motility and branching, by patterning a polylysine grid of narrow (2 or 5 ,m wide) intersecting lines. The shape of the intersections varied from circular nodes 15 ,m in diameter to simple crossed lines (nodeless intersections). Time-lapse recordings of cultured hippocampal neurons showed that simple variations in substrate geometry changed growth cone shape, and altered the rate of growth and the probability of branching. When crossing onto a node intersection the growth cone paused, often for hours, and microtubules appeared to defasciculate. Once beyond the node, filopodia and lamellipodia persisted at that site, sometimes forming a collateral branch. At nodeless intersections, the growth cone passed through with minimal hesitation, often becoming divided into separate areas of motility that led to the growth of separate branches. When several lines intersected at a common point, growth cones sometimes split into several subdivisions, resulting in the emergence of as many as five branches. Such experiments revealed an intrinsic preference for branches to form at angles less than 90°. These data show that simple changes in the geometry of a chemically homogeneous substrate are detected by the growth cone and can regulate axonal growth and the formation of branches. © 2006 Wiley Periodicals, Inc. J Neurobiol 66: 1183,1194, 2006 [source] Detection of the Sexual Identity of Conspecifics through Volatile Chemical Signals in a Territorial SalamanderETHOLOGY, Issue 3 2007Benjamin J. Dantzer Territorial red-backed salamanders (Plethodon cinereus) have been shown to use nonvolatile chemical signals in both territorial defense and to convey a variety of information to conspecifics. We investigated whether or not red-backed salamanders could determine the sexual identity of conspecifics through volatile chemical signals, and we explored their use in the context of territorial defense. We exposed male and female red-backed salamanders to four experimental treatments (i.e. filter papers that had been scent marked by male or female conspecifics for 1 and 5 d) and two control treatments (i.e. unscented filter papers for 1 and 5 d tests). The focal salamanders were prevented from physically accessing the scent marked filter papers and, presumably, some of the substrate scent marks had volatile components that were detected and interpreted by the focal salamanders. Both male and female red-backed salamanders spent significantly more time in threat displays when they were exposed to volatile chemical signals from same-sex conspecifics than they did toward similar signals from opposite-sex conspecifics. A similar statistical pattern was observed for the amount of chemosensory sampling exhibited by focal red-backed salamanders. From these results, we infer that red-backed salamanders can determine the sexual identity of conspecifics through volatile chemical signals, some of which may be used in territorial defense. Further, such airborne pheromones may influence the spatial organization of salamander territories on the forest floor. [source] Chemosensory Recognition of Familiar and Unfamiliar Conspecifics by Juveniles of the Iberian Wall Lizard Podarcis hispanicaETHOLOGY, Issue 4 2002Enrique Font Chemosensory recognition of familiar conspecifics has been reported in studies with members of several lizard families and may be advantageous to distinguish between intruders and neighbors or group members. However, few species have been studied and information on the ability to discriminate between familiar and unfamiliar conspecifics by chemosensory means is lacking for most lizard families. In this paper we ask whether juveniles of the Iberian wall lizard Podarcis hispanica (Lacertidae), can discriminate between chemical signals from familiar conspecifics with whom they have shared a terrarium for several months and those from unfamiliar conspecifics housed in a different terrarium. Experimental trials were conducted by transferring juveniles to a test terrarium with a filter paper substrate. We tested the responses of lizards to paper substrates labeled by familiar cage-mates, unfamiliar conspecifics, or unlabeled. Tongue-flicks and other behaviors in response to pheromonal stimuli were recorded for 10 min Juveniles directed more chemosensory behavior towards paper substrates bearing chemicals from familiar conspecifics than towards similar paper substrates labeled by unfamiliar conspecifics. These results indicate that juveniles in this lizard species can recognize familiar conspecifics and discriminate between familiar and unfamiliar individuals using only chemical stimuli. We discuss the role of habituation in familiar conspecific recognition and review possible explanations of the functional significance of this type of discrimination in lizards. [source] Single olfactory sensory neurons simultaneously integrate the components of an odour mixtureEUROPEAN JOURNAL OF NEUROSCIENCE, Issue 10 2003Patricia Duchamp-Viret Abstract Most odours are complex mixtures. However, the capacities of olfactory sensory neurons (OSNs) to process complex odour stimuli have never been explored in air-breathing vertebrates. To face this issue, the present study compares the electrical responses of single OSNs to two odour molecules, delivered singly and mixed together, in rats in vivo. This work is the first aimed at demonstrating that single OSNs simultaneously integrate several chemical signals and which, furthermore, attempts to describe such processes for the whole concentration range over which single OSNs can work. The results stress that complex interactions occur between components in odour mixtures and that OSN responses to such mixtures are not simply predictable from the responses to their components. Three types of interactions are described. They are termed suppression, hypoadditivity and synergy, in accord with psychophysical terminology. This allows us to draw links between peripheral odour reception and central odour coding. Indeed, events occurring in single OSNs may account for the dominating or even the masking effects of odour molecules in complex mixtures, i.e. for the prevailing action of a minor component in the final qualitative perception of a mixture. We conclude that our observations with binary mixtures anticipate the complexity of processes which may rise at the level of a single OSN in physiological conditions. Following this hypothesis, a natural odour would induce a multi-chemical integration at the level of single OSNs which may result in refining their individual odour-coding properties, leading them to play a crucial role in the final performance of the olfactory system. [source] Quorum-sensing in Gram-negative bacteriaFEMS MICROBIOLOGY REVIEWS, Issue 4 2001Neil A Whitehead Abstract It has become increasingly and widely recognised that bacteria do not exist as solitary cells, but are colonial organisms that exploit elaborate systems of intercellular communication to facilitate their adaptation to changing environmental conditions. The languages by which bacteria communicate take the form of chemical signals, excreted from the cells, which can elicit profound physiological changes. Many types of signalling molecules, which regulate diverse phenotypes across distant genera, have been described. The most common signalling molecules found in Gram-negative bacteria are N -acyl derivatives of homoserine lactone (acyl HSLs). Modulation of the physiological processes controlled by acyl HSLs (and, indeed, many of the non-acyl HSL-mediated systems) occurs in a cell density- and growth phase-dependent manner. Therefore, the term ,quorum-sensing' has been coined to describe this ability of bacteria to monitor cell density before expressing a phenotype. In this paper, we review the current state of research concerning acyl HSL-mediated quorum-sensing. We also describe two non-acyl HSL-based systems utilised by the phytopathogens Ralstonia solanacearum and Xanthomonas campestris. [source] Fish and mucus-dwelling bacteria interact to produce a kairomone that induces diel vertical migration in DaphniaFRESHWATER BIOLOGY, Issue 12 2006MERYEM BEKLIOGLU Summary 1. Bacterial populations associated with fish have previously been documented to be crucial for the production of chemical signals governing the interactions between predator fish and zooplankton prey. 2. In this study, we investigated the roles of fish and mucus-dwelling bacteria in kairomone production by conducting two sets of experiments related to elimination of bacteria with antibiotics and using fish mucus in bioassays of Daphnia pulex's diel vertical migration. 3. Daphnia's migratory response to the antibiotic-treated fish was about half the strength of the response to the fish cue treatment. Furthermore, when the same antibiotic-treated fish were removed from the antibiotic-containing water and transferred into control water for 24 and 48 h, the extent of D. pulex's migration depended on the length of the incubation period, apparently corresponding to the regeneration of bacterial colonies associated with mucus. The migration pattern observed in the 24 h treatment was similar to that of antibiotic-treated fish. On the other hand, a pronounced migration occurred in the 48 h following antibiotic treatment; here, we found a higher density of fish surface dwelling bacteria than at the start of the experiment. 4. In the experiment involving fish mucus, the mucus-enriched control water induced a weak response similar to antibiotic-treated fish. 5. On the basis of the results from the two experiments, we suggest that both fish and fish mucus-dwelling bacteria interact in the release of kairomone in ecologically relevant quantities. [source] Vesicle traffic through intercellular bridges in DU 145 human prostate cancer cellsJOURNAL OF CELLULAR AND MOLECULAR MEDICINE, Issue 3 2004Cristina Vidulescu Abstract We detected cell-to-cell communication via intercellular bridges in DU 145 human prostate cancer cells by fluorescence microscopy. Since DU 145 cells have deficient gap junctions, intercellular bridges may have a prominent role in the transfer of chemical signals between these cells. In culture, DU 145 cells are contiguous over several cell diameters through filopodial extensions, and directly communicate with adjacent cells across intercellular bridges. These structures range from 100 nm to 5 ,m in diameter, and from a few microns to at least 50,100 ,m in length. Time-lapse imagery revealed that (1) filopodia rapidly move at a rate of microns per minute to contact neighboring cells and (2) intercellular bridges are conduits for transport of membrane vesicles (1,3 ,m in diameter) between adjacent cells. Immunofluorescence detected alpha-tubulin in intercellular bridges and filopodia, indicative of microtubule bundles, greater than a micron in diameter. The functional meaning, interrelationship of these membrane extensions are discussed, along with the significance of these findings for other culture systems such as stem cells. Potential applications of this work include the development of anticancer therapies that target intercellular communication and controlling formation of cancer spheroids for drug testing. [source] Obligate asex in a rotifer and the role of sexual signalsJOURNAL OF EVOLUTIONARY BIOLOGY, Issue 1 2008C.-P. STELZER Abstract Transitions to asexuality have occurred in many animals and plants, yet the biological mechanisms causing such transitions have often remained unclear. Cyclical parthenogens, such as cladocerans, rotifers or aphids often give rise to obligate asexual lineages. In many rotifers, chemical signals that accumulate during population crowding trigger the induction of sexual stages. In this study, I tested two hypotheses on the origin of obligate parthenogenesis in the rotifer Brachionus calyciflorus: (i) that obligate parthenogens have lost the responsiveness to the sexual signal; and (ii) that obligate parthenogens have lost the ability to produce the sexual signal. Pairwise cross-induction assays among three obligate parthenogenetic strains and two cyclically parthenogenetic (sexual) strains were used to test these hypotheses. I found that obligate parthenogens can induce sexual reproduction in sexual strains, but not vice versa. This demonstrates that obligate parthenogens do still produce the sexual signal, but have lost responsiveness to that signal. [source] Effect of varying monoterpene concentrations on the response of Ips pini (Coleoptera: Scolytidae) to its aggregation pheromone: implications for pest management and ecology of bark beetlesAGRICULTURAL AND FOREST ENTOMOLOGY, Issue 4 2003Nadir Erbilgin Abstract 1,Host plant terpenes can influence attraction of conifer bark beetles to their aggregation pheromones: both synergistic and inhibitory compounds have been reported. However, we know little about how varying concentrations of individual monoterpenes affect responses. 2,We tested a gradient of ratios of ,-pinene, the predominant monoterpene in host pines in the Great Lakes region of North America, to Ips pini's pheromone, racemic ipsdienol plus lanierone. 3,Ips pini demonstrated a parabolic response, in which low concentrations of ,-pinene had no effect on attraction to its pheromone, intermediate concentrations were synergistic and high concentrations were inhibitory. These results suggest optimal release rates for population monitoring and suppression programmes. 4,Inhibition of bark beetle attraction to pheromones may be an important component of conifer defences. At terpene to pheromone ratios emulating emissions from trees actively responding to a first attack, arrival of flying beetles was low. This may constitute an additional defensive role of terpenes, which are also toxic to bark beetles at high concentrations. 5,Reduced attraction to a low ratio of ,-pinene to pheromone, as occurs when colonization densities become high and the tree's resin is largely depleted, might reflect a mechanism for preventing excessive crowding. 6,Thanasimus dubius, the predominant predator of I. pini, was also attracted to ipsdienol plus lanierone, but its response differed from that of its prey. Attraction increased across all concentrations of ,-pinene. This indicates that separate lures are needed to sample both predators and bark beetles effectively. It also provides an opportunity for maximizing pest removal while reducing adverse effects on beneficial species. This disparity further illustrates the complexity confronting natural enemies that track chemical signals to locate herbivores. [source] Melanophores: A model system for neuronal transport and exocytosis?JOURNAL OF NEUROSCIENCE RESEARCH, Issue 12 2007Sara Aspengren Abstract Black pigment cells, melanophores, from lower vertebrates are specialized in bidirectional and coordinated translocation of pigment granules, melanosomes, in the cytoplasm. Melanophores develop from the neuronal crest and are most abundant in the dermal and epidermal layers of the skin, where the intracellular distribution of the pigment significantly influences the color of the animal. The transport of pigment is dependent on an intact cytoskeleton and motor proteins associated with cytoskeletal components. The easily cultured melanophores have proved to be excellent models for organelle transport because the intracellular movements of pigment can be visualized via light microscopy, and the granules move in response to defined chemical signals. The ease of achieving a combination of morphological and functional transport studies is the advantage of the melanophore system, and studies on pigment cells have revealed new components of the transport machinery, including molecular motors, their adapters, and transfer of vesicles to other cells. Many cellular components are transported with a combination of the actin- and microtubule-based transport systems, and, since all eukaryotic organisms rely on functional intracellular transport and an intact cytoskeleton, studies on melanophores are important for many aspects of cell biology, including axonal transport. In this review, we present an overview of the research on the pigment transport system and the potential use of pigment cells as a model system. © 2006 Wiley-Liss, Inc. [source] Mechano-biology of skeletal muscle hypertrophy and regeneration: Possible mechanism of stretch-induced activation of resident myogenic stem cellsANIMAL SCIENCE JOURNAL, Issue 1 2010Ryuichi TATSUMI ABSTRACT In undamaged postnatal muscle fibers with normal contraction and relaxation activities, quiescent satellite cells of resident myogenic stem cells are interposed between the overlying external lamina and the sarcolemma of a subjacent mature muscle fiber. When muscle is injured, exercised, overused or mechanically stretched, these cells are activated to enter the cell proliferation cycle, divide, differentiate, and fuse with the adjacent muscle fiber, and are responsible for regeneration and work-induced hypertrophy of muscle fibers. Therefore, a mechanism must exist to translate mechanical changes in muscle tissue into chemical signals that can activate satellite cells. Recent studies of satellite cells or single muscle fibers in culture and in vivo demonstrated the essential role of hepatocyte growth factor (HGF) and nitric oxide (NO) radical in the activation pathway. These experiments have also reported that mechanically stretching satellite cells or living skeletal muscles triggers the activation by rapid release of HGF from its extracellular tethering and the subsequent presentation to the receptor c-met. HGF release has been shown to rely on calcium-calmodulin formation and NO radical production in satellite cells and/or muscle fibers in response to the mechanical perturbation, and depend on the subsequent up-regulation of matrix metalloproteinase (MMP) activity. These results indicate that the activation mechanism is a cascade of events including calcium ion influx, calcium-calmodulin formation, NO synthase activation, NO radical production, MMP activation, HGF release and binding to c-met. Better understanding of ,mechano-biology' on the satellite cell activation is essential for designing procedures that could enhance muscle growth and repair activities in meat-animal agriculture and also in neuromuscular disease and aging in humans. [source] soil-root-canopy interactionsANNALS OF APPLIED BIOLOGY, Issue 2 2001I J BINGHAM Summary When supplies of water and mineral nutrients are adequate, crop growth is determined by the amount of solar radiation intercepted over the season and the efficiency of its conversion into dry matter. Soil factors such as drought, nutrient availability, salinity, waterlogging, mechanical impedance and root-infecting pathogens can be a serious constraint to yield and operate through effects on the growth, photosynthetic activity and duration of the canopy, and on the partitioning of biomass to harvested parts. One approach to overcome restrictions on the canopy and enhance yield is to modify root systems so that they are better suited to the prevailing soil conditions. This might be achieved through genetic improvement or by cultural practices. A better understanding of the physiology of root systems is required to identify appropriate root traits for selection or management. Not only should this encompass considerations of the function of roots in the capture of water and nutrients and the provision of anchorage, but also new concepts about the role of chemical signals in the regulation of the canopy. Greater emphasis must be placed on field-based research. The growth, development and activity of roots in the field can differ markedly from those in most laboratory experiments, because field soils are more complex in structure and differ in their biological, chemical and physical properties. It is argued that a decline in field-based research of crop root systems, as seen in the UK over the last 15,20 years, could, if allowed to continue, generate a skills gap which may undermine future exploitation of discoveries made at the cell and molecular level. [source] Geochemistry as an aid in archaeological prospection and site interpretation: current issues and research directionsARCHAEOLOGICAL PROSPECTION, Issue 1 2009S. Oonk Abstract Human habitation may significantly affect the chemical soil composition leading to enrichments and depletions of specific chemical elements and the formation of archaeological soils. Prospection and interpretation of sites by means of element analysis of soils requires appropriate and well-tested geochemical methodologies. In this paper element analysis in archaeological prospection and site interpretation is briefly reviewed and three major unresolved issues are discussed: (i) how to distinguish archaeological chemical signals in soils from modern and geogenic signals; (ii) what role do geochemical processes play in the formation of archaeological soils; (iii) how to implement geochemical methods in archaeological research programmes. These issues are addressed with reference to the geochemical literature on retention and sequestration pathways of presumed anthropogenic elements in soils and analytical procedures. Based on the acquired knowledge, several directions for future research are proposed. Copyright © 2009 John Wiley & Sons, Ltd. [source] Crystallization and rhenium MAD phasing of the acyl-homoserinelactone synthase EsaIACTA CRYSTALLOGRAPHICA SECTION D, Issue 12 2001William T. Watson Acyl-homoserine- l -lactones (AHLs) are diffusible chemical signals that are required for virulence of many Gram-negative bacteria. AHLs are produced by AHL synthases from two substrates, S -adenosyl- l -methionine and acyl-acyl carrier protein. The AHL synthase EsaI, which is homologous to the AHL synthases from other pathogenic bacterial species, has been crystallized in the primitive tetragonal space group P43, with unit-cell parameters a = b = 66.40, c = 47.33,Å. The structure was solved by multiple-wavelength anomalous diffraction with a novel use of the rhenium anomalous signal. The rhenium-containing structure has been refined to a resolution of 2.5,Å and the perrhenate ion binding sites and liganding residues have been identified. [source] To b or not to b: A pheromone-binding protein regulates colony social organization in fire antsBIOESSAYS, Issue 1 2005Michael J.B. Krieger A major distinction in the social organization of ant societies is the number of reproductive queens that reside in a single colony. The fire ant Solenopsis invicta exists in two distinct social forms, one with colonies headed by a single reproductive queen and the other containing several to hundreds of egg-laying queens. This variation in social organization has been shown to be associated with genotypes at the gene Gp-9. Specifically, single-queen colonies have only the B allelic variant of this gene, whereas multiple-queen colonies always have the b variant as well. Subsequent studies revealed that Gp-9 shares the highest sequence similarity with genes encoding pheromone-binding proteins (PBPs). In other insects, PBPs serve as central molecular components in the process of chemical recognition of conspecifics. Fire ant workers regulate the number of egg-laying queens in a colony by accepting queens that produce appropriate chemical signals and destroying those that do not. The likely role of GP-9 in chemoreception suggests that the essential distinction in colony queen number between the single and multiple-queen form originates from differences in workers' abilities to recognize queens. Other, closely related fire ant species seem to regulate colony social organization in a similar fashion. BioEssays 27:91,99, 2005. © 2004 Wiley Periodicals, Inc. [source] Spider sex pheromones: emission, reception, structures, and functionsBIOLOGICAL REVIEWS, Issue 1 2007A. C. Gaskett Abstract Spiders and their mating systems are useful study subjects with which to investigate questions of widespread interest about sexual selection, pre- and post-copulatory mate choice, sperm competition, mating strategies, and sexual conflict. Conclusions drawn from such studies are broadly applicable to a range of taxa, but rely on accurate understanding of spider sexual interactions. Extensive behavioural experimentation demonstrates the presence of sex pheromones in many spider species, and recent major advances in the identification of spider sex pheromones merit review. Synthesised here are the emission, transmission, structures, and functions of spider sex pheromones, with emphasis on the crucial and dynamic role of sex pheromones in female and male mating strategies generally. Techniques for behavioural, chemical and electrophysiological study are summarised, and I aim to provide guidelines for incorporating sex pheromones into future studies of spider mating. In the spiders, pheromones are generally emitted by females and received by males, but this pattern is not universal. Female spiders emit cuticular and/or silk-based sex pheromones, which can be airborne or received via contact with chemoreceptors on male pedipalps. Airborne pheromones primarily attract males or elicit male searching behaviour. Contact pheromones stimulate male courtship behaviour and provide specific information about the emitter's identity. Male spiders are generally choosy and are often most attracted to adult virgin females and juvenile females prior to their final moult. This suggests the first male to mate with a female has significant advantages, perhaps due to sperm priority patterns, or mated female disinterest. Both sexes may attempt to control female pheromone emission, and thus dictate the frequency and timing of female mating, reflecting the potentially different costs of female signalling and/or polyandry to both sexes. Spider sex pheromones are likely to be lipids or lipid soluble, may be closely related to primary metabolites, and are not necessarily species specific, although they can still assist with species recognition. Newer electrophysiological techniques coupled with chemical analyses assist with the identification of sex pheromone compounds. This provides opportunities for more targeted behavioural experimentation, perhaps with synthetic pheromones, and for theorising about the biosynthesis and evolution of chemical signals generally. Given the intriguing biology of spiders, and the critical role of chemical signals for spiders and many other animal taxa, a deeper understanding of spider sex pheromones should prove productive. [source] | |||||||||||||