Sexual pheromone detection using PANI.Ag nanohybrid and PANI/PSS nanocomposite nanosensors

In this study, polyaniline/poly (styrene sulfonate) (PANI/PSS) nanocomposite and polyaniline.silver (PANI.Ag) nanohybrid thin films were obtained in cantilever nanosensors surface. The developed films were characterized in relation to topography, roughness,...

Correction: Sexual pheromone detection using PANI·Ag nanohybrid and PANI/PSS nanocomposite nanosensors

Correction for ‘Sexual pheromone detection using PANI·Ag nanohybrid and PANI/PSS nanocomposite nanosensors’ by Janine Martinazzo et al., Anal. Methods, 2021, 13, 3900–3908, DOI: 10.1039/d1ay00987g.

The mating behavior of Leucothyreus marginaticollis Blanchard, 1843 (Coleoptera: Scarabaeidae: Rutelinae)

In Brazil, there are several species of the genus Leucothyreus Macleay, 1819 occurring throughout the country; however, there are only a few studies describing their biological aspects, times of occurrence, associations of adults and juveniles with native or cropped plants, as well as their mating behavior. Thus, this study aimed to assess the mating behavior of Leucothyreus marginaticollis Blanchard, 1843. The study took place in an experimental area of the State University of Mato Grosso do Sul, in Aquidauana, MS, Brazil. Firstly, we sampled adult insects using light traps, from October to November 2013. Simultaneously, we registered the flight period in the field. Afterward, in the laboratory, males and females were separated and then combined into couples for observations of the mating steps. A large number of the adults mated, which lasted on average 22.71 min and occurred from 7 to 11 pm. After mating, part of the males released the females and the other part remained attached to them, which must have happened as an attempt to inhibit other males from mating with them. Moreover, a few females refused to mate with the established male, reinforcing the fact that the pairing of couples occurs after chemical identification among adults. In the field, the largest amount of adults was collected from 8 to 10 pm. Regarding eating habits, adults feed mostly on acerola leaves and flowers (Malpighia emarginata DC, Malpighiaceae), mastic gum leaves (Myracrodruon urundeuva Allemão, Anacardiaceae), grapes (Vitis vinifera L., Vitaceae), apples (Malus domestica Borkh., Rosaceae), and bananas (Musa sp. L., Musaceae). To the end of the experiment, we could clarify the mating steps of L. marginaticollis in order to assist in further extraction and identification of sexual pheromone.

Sexual pheromone modulates the frequency of cytosolic Ca2+ bursts in Saccharomyces cerevisiae

Transient and highly regulated elevations of cytosolic Ca2+ control a variety of cellular processes. Bulk measurements using radioactive Ca2+ and the luminescent sensor aequorin have shown that in response to pheromone, budding yeast cells undergo a rise of cytosolic Ca2+ that is mediated by two import systems composed of the Mid1-Cch1-Ecm7 protein complex and the Fig1 protein. Although this response has been widely studied, there is no treatment of Ca2+ dynamics at the single-cell level. Here, using protein calcium indicators, we show that both vegetative and pheromone-treated yeast cells exhibit discrete and asynchronous Ca2+ bursts. Most bursts reach maximal amplitude in 1–10 s, range between 7 and 30 s, and decay in a way that fits a single-exponential model. In vegetative cells, bursts are scarce but preferentially occur when cells are transitioning G1 and S phases. On pheromone presence, Ca2+ burst occurrence increases dramatically, persisting during cell growth polarization. Pheromone concentration modulates burst frequency in a mechanism that depends on Mid1, Fig1, and a third, unidentified, import system. We also show that the calcineurin-responsive transcription factor Crz1 undergoes nuclear localization bursts during the pheromone response.

Genetic mapping of male pheromone response in the European corn borer identifies candidate genes regulating neurogenesis

The sexual pheromone communication system of moths is a model system for studies of the evolution of reproductive isolation. Females emit a blend of volatile components that males detect at a distance. Species differences in female pheromone composition and male response directly reinforce reproductive isolation in nature, because even slight variations in the species-specific pheromone blend are usually rejected by the male. The mechanisms by which a new pheromone signal–response system could evolve are enigmatic, because any deviation from the optimally attractive blend should be selected against. Here we investigate the genetic mechanisms enabling a switch in male response. We used a quantitative trait locus-mapping approach to identify the genetic basis of male response in the two pheromone races of the European corn borer, Ostrinia nubilalis. Male response to a 99:1 vs. a 3:97 ratio of the E and Z isomers of the female pheromone is governed by a single, sex-linked locus. We found that the chromosomal region most tightly linked to this locus contains genes involved in neurogenesis but, in accordance with an earlier study, does not contain the odorant receptors expressed in the male antenna that detect the pheromone. This finding implies that differences in the development of neuronal pathways conveying information from the antenna, not differences in pheromone detection by the odorant receptors, are primarily responsible for the behavioral response differences among the males in this system. Comparison with other moth species reveals a previously unexplored mechanism by which male pheromone response can change in evolution.