bric à brac controls sex pheromone choice by male European corn borer moths

The sex pheromone system of ~160,000 moth species acts as a powerful form of assortative mating whereby females attract conspecific males with a species-specific blend of volatile compounds. Understanding how female pheromone production and male preference coevolve to produce this diversity requires knowledge of the genes underlying change in both traits. In the European corn borer moth, pheromone blend variation is controlled by two alleles of an autosomal fatty-acyl reductase gene expressed in the female pheromone gland (pgFAR). Here we show that asymmetric male preference is controlled by cis-acting variation in a sex-linked transcription factor expressed in the developing male antenna, bric à brac (bab). A genome-wide association study of preference using pheromone-trapped males implicates variation in the 293 kb bab intron 1, rather than the coding sequence. Linkage disequilibrium between bab intron 1 and pgFAR further validates bab as the preference locus, and demonstrates that the two genes interact to contribute to assortative mating. Thus, lack of physical linkage is not a constraint for coevolutionary divergence of female pheromone production and male behavioral response genes, in contrast to what is often predicted by evolutionary theory.

Identification and characterisation of female released sex pheromone components of jute semilooper, Anomis sabulifera Guenee (Lepidoptera: Noctuidae)

Aim: Identification and characterization of female released sex pheromone components of jute semilooper, Anomis sabulifera Guenee (Lepidoptera: Noctuidae) from female pheromone gland extracts. Methodology: Electroantennogram (EAG) was carried for studying the antennal response; Gas Chromatography coupled with Electro antenna Detector (GC-EAD) was conducted for studying the antennal response of eluted compounds from female pheromone gland extract; Gas Chromatography and Mas Spectrophotometry (GC-MS) was conducted for characterization or getting complete profile of compounds present in the female pheromone gland extract based on retention times. Wind tunnel assay was conducted for studying the behavioural responses of eluted compounds from the female pheromone gland extract. Results: GC-MS profile of female pheromone gland extract revealed that the GC-EAD active region constituted (6Z,9Z)-heneicosadiene, (3Z,6Z,9Z)-heneicosatriene as active compounds. Preliminary wind tunnel studies for olfactory and behavioural responses showed blend of (6Z,9Z)-heneicosadiene (3 parts) + (3Z,6Z,9Z)-heneicosatriene (1 part) enticed 60% male adults. Interpretation: (6Z,9Z)-heneicosadiene and (3Z,6Z,9Z)-heneicosatriene are likely to be active pheromone components present in female sex pheromone glands. Blending of these two compounds in precise ratio can enhance the effectiveness of pheromone and can be used as effective strategy in jute IPM. Key words: Anomis sabulifera, Jute semilooper, Noctuidae, Sex pheromone, (6Z,9Z)-heneicosadiene, (3Z,6Z,9Z)-heneicosatriene

Z4-11Al mediates olfactory attraction and courtship in Drosophila melanogaster

Specific mate communication and recognition underlies reproduction and hence speciation. Mate communication evolves during adaptation to ecological niches and makes use of social signals and habitat cues. Our study provides new insights in Drosophila melanogaster premating olfactory communication, showing that female pheromone Z4-11Al and male pheromone cVA interact with food odour in a sex-specific manner. Furthermore, Z4-11Al, which mediates upwind flight attraction in both sexes, also elicits courtship in experienced males. Twin variants of the olfactory receptor Or69a are co-expressed in the same olfactory sensory neurons, and feed into the same glomerulus in the antennal lobe. Female pheromone Z4-11Al is perceived via Or69aB, while the food odorant (R)-linalool is a main ligand for the other variant, Or69aA. That Z4-11Al mediates courtship in experienced males, not (R)-linalool, is probably due to courtship learning. Behavioural discrimination is reflected by calcium imaging of the antennal lobe, showing distinct glomerular activation patterns by these two compounds. Male sex pheromone cVA is known to affect male and female courtship at close range, but does not elicit upwind flight attraction as a single compound, in to contrast to Z4-11Al. A blend of cVA and the food odour vinegar attracted females, while a blend of female pheromone Z4-11Al and vinegar attracted males instead. Sex-specific upwind flight attraction to blends of food volatiles and male and female pheromone, respectively, adds a new element to Drosophila olfactory premating communication and is an unambiguous paradigm for identifying the behaviourally active components, towards a more complete concept of food-pheromone odour objects.

Transcriptome analysis of the sex pheromone gland and pheromone biosynthetic pathway in Eogystia hippophaecolus

The moth Eogystia hippophaecolus (Hua et al.) is a major threat to sea buckthorn plantations in China. Specific and highly efficient artificial sex pheromone traps have been developed and used to control this pest species. However, the biosynthesis of sex pheromones Z7-14:Ac and E3-14:Ac remains poorly understood.Results We investigated the female pheromone gland transcriptome of E. hippophaecolus and identified two pheromone biosynthesis-activating neuropeptides (PBANs), two pheromone biosynthesis-activating neuropeptide receptors (PBANrs), five acetyl-CoA carboxylases (ACCs), six fatty acid synthases (FASs), 16 Acyl-CoA desaturases (DESs), 26 reductases (REDs), 13 acetyltransferases (ACTs), one fatty acid transport protein (FATP), one acyl-CoA-binding protein (ACBP), and five elongation of very long-chain fatty acid proteins (ELOs) in pheromone biosynthesis pathways. Additionally, we identified 11 odorant-degrading enzymes (ODEs) and 16 odorant-binding proteins (OBPs), 14 chemosensory proteins (CSPs), two sensory neuron membrane proteins (SNMPs), three odorant receptors (ORs), seven ionotropic receptors (IRs), and six gustatory receptors (GRs).Conclusions 77 unigenes involved in female pheromone biosynthesis, 31 chemoreception proteins and 11 odorant degradation enzymes were identified, which provided insight into the regulation of the pheromone components and pheromone recognition in the sex gland, and knowledge pertinent to new integrated pest management strategy of interference pheromone biosynthesis and recognition.

Experimental investigations on the partner-finding behaviour of Isohypsibius dastychi (Isohypsibiidae: Tardigrada)

The present study gives the first detailed results on the partner-finding behaviour of tardigrades. We investigated whether the finding of mating partners by Isohypsibius dastychi followed certain criteria that are expected if pheromone signals are involved. For this purpose, tardigrade pairs were positioned in an arena, at a range of distances from each other. Only those females that were ready for mating attracted the male. The smaller the initial distance between them, the more directly the male headed for the female. The route travelled and time taken increased exponentially with increasing initial distance between partners, which means that the male lost orientation with respect to the female the larger the distance between the pair became. The findings indirectly suggest a yet undetermined female pheromone, which produces a concentration gradient in the water and loses strength quickly in terms of distance. Our assumption is supported by rare observations of sperm release without direct contact between partners that nevertheless resulted in fertile offspring. The observation that the female partners in this no-contact mating behaviour then deposited their eggs (a behaviour that was never seen when males were absent) suggests that they, likewise, can sense a fresh ejaculate of spermatozoa in their direct vicinity.

The Effect of Female Pheromone on the Functional State of Young Men

Introduction.Modern studies show that the presentation of smell of female mice before male mice infection with the influenza virus activates non-specific immune response which protects male mice from infection of the upper respiratory tract and reducing their mortality. However the researches have not studied the adaptive effect of female sexual pheromone on men.The aimof this work was to study the effect of odor of synthetic analogue of natural female pheromone (Osmopherine) on the functional state of young men often suffering from acute respiratory infections (ARI) and allergic diseases.Materials and methods.We studied four-week effect of Osmopherine on the psycho-emotional state, the concentration of hormones (testosterone, cortisol) and immunoglobulins (sIgA, total IgG), the percentage of leukocytes in the blood and the individual smell of young men, who have ARI more than 4 times a year or an allergic disease. The study involved 117 boys aged 19–23 years. Olfactory testing of individual odor samples of young men was carried out by young women (n = 32) aged 18–22 years.Results.It was found that female pheromone has a positive effect on the functional state of men with different immune systems. However its effect is caused by the pathogenesis of the disease. Application of Osmopherine in men with reduced immunity causes an increased activity, improved mood, reduced anxiety and stabilized testosterone level. Men with allergic diseases did not have the same effect. A significant 2 times decrease in the content of eosinophils was found, which indirectly indicates the decrease in the activity of the delayed phase of allergic reactions of immediate type.Conclusion.The immune system functions according to its internal laws and programs. However its activity for the benefit of the whole body is integrated and regulated by the nervous and endocrine systems. Therefore modulating effect on the functioning of the immune system can be mediated through the presentation of pheromones.

Within-population variability in a moth sex pheromone blend, part 2: selection towards fixation

To understand how variation in sexual communication systems evolves, the genetic architecture underlying sexual signals and responses needs to be identified. Especially in animals where mating signals are important for mate recognition, and signals and responses are governed by independently assorting genes, it is difficult to envision how signals and preferences can (co)evolve. Moths are a prime example of such animals. In the noctuid moth Heliothis virescens , we found within-population variation in the female pheromone. In previous selection experiments followed by quantitative trait locus (QTL) analysis and expression analysis of candidate desaturase genes, we developed a model involving a trans -acting repressor of the delta-11-desaturase. In our current study with new selection lines, we fixed the most extreme phenotype and found a single underlying mutation: a premature stop codon in the first coding exon of delta-11-desaturase, which we could trace back to its origin in the laboratory. Interestingly, we found no pleiotropic effects of this knock-out mutation on the male physiological or behavioural response, or on growth or fertility. This finding is in contrast to Drosophila melanogaster , where a single desaturase gene affects both female pheromone production and male behavioural response, but similar to other Lepidoptera where these traits are under independent genetic control. To our knowledge, this is the first time that a single point mutation has been identified that underlies the phenotypic variation in the pheromone signal of a moth.