Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 20 de 8.726
Filtrar
1.
Elife ; 112022 Sep 20.
Artigo em Inglês | MEDLINE | ID: mdl-36125436

RESUMO

Computational model reveals why pausing to sniff the air helps animals track a scent when they are far away from the source.


Assuntos
Odorantes , Olfato , Animais , Feromônios
2.
Nat Commun ; 13(1): 5509, 2022 Sep 20.
Artigo em Inglês | MEDLINE | ID: mdl-36127350

RESUMO

Microbial production of cannabinoids promises to provide a consistent, cheaper, and more sustainable supply of these important therapeutic molecules. However, scaling production to compete with traditional plant-based sources is challenging. Our ability to make strain variants greatly exceeds our capacity to screen and identify high producers, creating a bottleneck in metabolic engineering efforts. Here, we present a yeast-based biosensor for detecting microbially produced Δ9-tetrahydrocannabinol (THC) to increase throughput and lower the cost of screening. We port five human cannabinoid G protein-coupled receptors (GPCRs) into yeast, showing the cannabinoid type 2 receptor, CB2R, can couple to the yeast pheromone response pathway and report on the concentration of a variety of cannabinoids over a wide dynamic and operational range. We demonstrate that our cannabinoid biosensor can detect THC from microbial cell culture and use this as a tool for measuring relative production yields from a library of Δ9-tetrahydrocannabinol acid synthase (THCAS) mutants.


Assuntos
Técnicas Biossensoriais , Canabinoides , Canabinoides/metabolismo , Dronabinol/metabolismo , Humanos , Feromônios/metabolismo , Saccharomyces cerevisiae/genética , Saccharomyces cerevisiae/metabolismo , Fluxo de Trabalho
3.
Sci Rep ; 12(1): 15768, 2022 Sep 21.
Artigo em Inglês | MEDLINE | ID: mdl-36130986

RESUMO

Humans have used weaver ants, Oecophylla smaragdina, as biological control agents to control insect pests in orchards for many centuries. Over recent decades, the effectiveness of weaver ants as biological control agents has been attributed in part to deterrent and oviposition inhibiting effects of kairomones produced by the ants, but the chemical identity of these kairomones has remained unknown. We have identified the kairomone responsible for deterrence and oviposition inhibition by O. smaragdina, providing a significant advance in understanding the chemical basis of their predator/prey interactions. Olfactometer assays with extracts from weaver ants demonstrated headspace volatiles to be highly repellent to Queensland fruit fly, Bactrocera tryoni. Using electrophysiology and bioassays, we demonstrate that this repellence is induced by a single compound, 1-octanol. Of 16 compounds identified in O. smaragdina headspace, only 1-octanol evoked an electrophysiological response from B. tryoni antennae. Flies had greatly reduced oviposition and spent significantly less time in an olfactometer arm in the presence of 1-octanol or a synthetic blend of headspace volatiles containing 1-octanol than in the presence of a synthetic blend of headspace volatiles without 1-octanol, or clean air. Taken together, our results demonstrate that 1-octanol is the functional kairomone component of O. smaragdina headspace that explains repellence and oviposition deterrence, and is hence an important contributor to the effectiveness of these ants as biological control agents.


Assuntos
Formigas , Tephritidae , 1-Octanol , Animais , Formigas/fisiologia , Agentes de Controle Biológico , Feminino , Humanos , Oviposição/fisiologia , Feromônios/farmacologia , Extratos Vegetais/farmacologia , Tephritidae/fisiologia
4.
PLoS Comput Biol ; 18(9): e1010305, 2022 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-36107824

RESUMO

Honeybees protect their colony against vertebrates by mass stinging and they coordinate their actions during this crucial event thanks to an alarm pheromone carried directly on the stinger, which is therefore released upon stinging. The pheromone then recruits nearby bees so that more and more bees participate in the defence. However, a quantitative understanding of how an individual bee adapts its stinging response during the course of an attack is still a challenge: Typically, only the group behaviour is effectively measurable in experiment; Further, linking the observed group behaviour with individual responses requires a probabilistic model enumerating a combinatorial number of possible group contexts during the defence; Finally, extracting the individual characteristics from group observations requires novel methods for parameter inference. We first experimentally observed the behaviour of groups of bees confronted with a fake predator inside an arena and quantified their defensive reaction by counting the number of stingers embedded in the dummy at the end of a trial. We propose a biologically plausible model of this phenomenon, which transparently links the choice of each individual bee to sting or not, to its group context at the time of the decision. Then, we propose an efficient method for inferring the parameters of the model from the experimental data. Finally, we use this methodology to investigate the effect of group size on stinging initiation and alarm pheromone recruitment. Our findings shed light on how the social context influences stinging behaviour, by quantifying how the alarm pheromone concentration level affects the decision of each bee to sting or not in a given group size. We show that recruitment is curbed as group size grows, thus suggesting that the presence of nestmates is integrated as a negative cue by individual bees. Moreover, the unique integration of exact and statistical methods provides a quantitative characterisation of uncertainty associated to each of the inferred parameters.


Assuntos
Abelhas , Comportamento Animal , Comportamento Social , Animais , Abelhas/fisiologia , Comportamento Animal/fisiologia , Feromônios/fisiologia
5.
Sci Rep ; 12(1): 15594, 2022 Sep 16.
Artigo em Inglês | MEDLINE | ID: mdl-36114203

RESUMO

Olfactory communication is common in felids. We observed two scent-markings, urine spraying and scraping the ground with hind paws during excretion, of 25 captive cheetahs. We analyzed the association of sniffing with the timing of urine spraying and scraping, and differences in these behaviors based on sex, age, and captive environment to understand the olfactory communication among cheetahs. Both scent-markings were strongly associated with sniffing, especially scraping, and the presence or absence of scent was thought to be a trigger. Both behaviors were observed only in adults; scraping was observed only in males. To our knowledge, this study was first to confirm the discharge of secretions from the anal glands during scraping. The frequencies of both behaviors were significantly higher in males kept in shared enclosures containing other individuals than in males kept in monopolized enclosures, while there was no difference in the frequencies among females. Female cheetahs are solitary and have non-exclusive home range, whereas male cheetahs are either solitary or live in coalition groups and there are territorial and non-territorial males. Our results could be attributed to the differences in sociality between the sexes and effect of the living environment.


Assuntos
Acinonyx , Animais , Feminino , Humanos , Masculino , Odorantes , Feromônios , Olfato , Territorialidade
6.
J Agric Food Chem ; 70(37): 11792-11803, 2022 Sep 21.
Artigo em Inglês | MEDLINE | ID: mdl-36095120

RESUMO

Odorant-binding protein (OBP) is a potential target for developing insect behavior control agents due to its properties in transporting semiochemicals. In this study, 12 novel jasmonic acid (JA) derivatives were rationally designed and synthesized based on the binding features between Acyrthosiphon pisum OBP3 (ApisOBP3) and compound D1 [(E)-3,7-dimethylocta-2,6-dien-1-yl 2-(3-oxo-2-pentylcyclopentyl)acetate] with a binding affinity (Kd) of 26.79 µM. Most novel JA derivatives displayed better binding affinities than D1 (Kd = 1-26 µM). Among them, compound 6b [(E)-3,7-dimethylocta-2,6-dien-1-yl-2-((Z)-3-((acryloyloxy)imino)-2-pentylcyclopentyl)acetate] is the most promising compound with an excellent Kd of 1.33 µM and a significant repellent activity with repellent rates of 50-60% against A. pisum and Myzus persicae. Both hydrophobic and electrostatic interactions were found to contribute significantly to the binding of 6b to ApisOBP3. This study provides significant guidance for the rational design and efficient identification of novel aphid repellents based on aphid OBPs.


Assuntos
Afídeos , Repelentes de Insetos , Receptores Odorantes , Acetatos/metabolismo , Acetatos/farmacologia , Animais , Afídeos/química , Ciclopentanos , Proteínas de Insetos/metabolismo , Oxilipinas , Feromônios/metabolismo , Receptores Odorantes/metabolismo
7.
Pestic Biochem Physiol ; 187: 105180, 2022 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-36127042

RESUMO

Bark beetles rely on detoxifying enzymes to resist the defensive terpenoids of the host tree. Insect cytochrome P450 (CYPs) plays a key role in the detoxification of pesticides and plant allelochemicals. CYP6 family is unique to Insecta, and its biochemical function is basically related to the metabolism of exogenous substances. In this study, we sequenced and characterized the full-length cDNAs of two CYP6 genes from Chinese white pine beetle, Dendroctonus armandi. Spatiotemporal expression profiling revealed that the expression of CYP6CR2 and CYP6DE5 was higher in larval and adult stages of D. armandi than that in other developmental stages, and that two genes predominantly expressed in brain, midgut, fat body, Malpighian tubules or hemolymph. The expression of CYP6CR2 and CYP6DE5 was significantly induced after feeding on the phloem of Pinus armandii and exposure to six stimuli [(±)- α -pinene, (-)-α-pinene, (-)-ß-pinene, (+)-3-carene, (±)-limonene and turpentine]. Importantly, silencing CYP6CR2 and CYP6DE5 separately could increase the sensitivity, led to a significant reduction of the activity of P450, resulting a significant increase in adult mortality after treatment with terpenoids. The comprehensive results of this study showed that in the process of host selection and colonization, the functions of CYPs were mainly to hydrolyze the chemical defense of the host and degrade odor molecules. These findings may help to develop new treatments to control this important pest.


Assuntos
Besouros , Praguicidas , Pinus , Animais , Monoterpenos Bicíclicos , China , Besouros/metabolismo , Sistema Enzimático do Citocromo P-450/metabolismo , Família 6 do Citocromo P450/metabolismo , Limoneno , Monoterpenos/metabolismo , Monoterpenos/farmacologia , Praguicidas/metabolismo , Feromônios/metabolismo , Terpenos , Terebintina/metabolismo
8.
Proc Natl Acad Sci U S A ; 119(40): e2205942119, 2022 Oct 04.
Artigo em Inglês | MEDLINE | ID: mdl-36122198

RESUMO

Spiders, the most specious taxon of predators, have evolved an astounding range of predatory strategies, including group hunting, specialized silk traps, pheromone-loaded bolas, and aggressive mimicry. Spiders that hunt prey defended with behavioral, mechanical, or chemical means are under additional selection pressure to avoid injury and death. Ants are considered dangerous because they can harm or kill their predators, but some groups of spiders, such as the Theridiidae, have a very high diversification of ant-hunting species and strategies [J. Liu et al., Mol. Phylogenet. Evol. 94, 658-675 (2016)]. Here, we provide detailed behavioral analyses of the highly acrobatic Australian ant-slayer spider, Euryopis umbilicata (Theridiidae), that captures much larger and defended Camponotus ants on vertical tree trunks. The hunting sequence consists of ritualized steps performed within split seconds, resulting in an exceptionally high prey capture success rate.


Assuntos
Formigas , Aranhas , Animais , Austrália , Feromônios , Seda , Árvores
9.
J Chem Phys ; 157(9): 094708, 2022 Sep 07.
Artigo em Inglês | MEDLINE | ID: mdl-36075737

RESUMO

Environmental conditions can alter olfactory scent and chemical communication among biological species. In particular, odorant molecules interact with aerosols. Thermodynamics variables governing the adsorption from air to water surface of bombykol, the most studied pheromone, and of three derivative molecules, bombykal, bombykoic acid, and bombykyle acetate, are computed by steered and un-biased molecular dynamics in order to compare the role of their polar head group on adsorption on aqueous aerosols. When adsorbed, the molecule center of mass stands at about 1.2 Å from the interface and oscillates on the same length scale, trapped in an energy well. Gibbs energy of adsorption and desorption time of bombykol are found to be 9.2 kBT and 59 µs, respectively. The following ordering between the molecules is observed, reading from the more to the least adsorbed: bombykoic acid > bombykol > bombykoic acetate > bombykal. It originates from a complex interplay of entropy and enthalpy. The entropy and enthalpy of adsorption are discussed in the light of structural arrangement, H-bonding, and hydrophilic tail positioning of the molecules at the interface. Our results show that, when dispersed in the air, pheromones adsorb on aqueous aerosols. However, the individual residence time is quite short on pure water surfaces. Aerosols can, therefore, only have a decisive influence on chemical communication through collective effects or through their chemical composition that is generally more complex than that of a pure water surface.


Assuntos
Feromônios , Água , Adsorção , Aerossóis , Termodinâmica , Água/química
10.
Int J Mol Sci ; 23(17)2022 Aug 29.
Artigo em Inglês | MEDLINE | ID: mdl-36077215

RESUMO

The global decline of natural oyster populations emphasizes the need to improve our understanding of their biology. Understanding the role of chemical cues from conspecifics on how oysters occupy appropriate substrata is crucial to learning about their evolution, population dynamics, and chemical communication. Here, a novel role of a macromolecular assembly of shell matrix proteins which act as Crassostrea gigas Settlement Pheromone Protein Components in adult shells is demonstrated as the biological cue responsible for gregarious settlement on conspecifics. A bioassay-guided fractionation approach aided by biochemical and molecular analyses reveals that Gigasin-6 isoform X1 and/or X2 isolated from adult shells is the major inducing cue for larval settlement and may also play a role in postlarva-larva settlement interactions. Other isolated Stains-all-stainable acidic proteins may function as a co-factor and a scaffold/structural framework for other matrix proteins to anchor within this assembly and provide protection. Notably, conspecific cue-mediated larval settlement induction in C. gigas presents a complex system that requires an interplay of different glycans, disulfide bonds, amino acid groups, and phosphorylation crosstalk for recognition. These results may find application in the development of oyster aquacultures which could help recover declining marine species and as targets of anti-fouling agents.


Assuntos
Crassostrea , Ácidos/metabolismo , Exoesqueleto/metabolismo , Animais , Sinais (Psicologia) , Larva , Feromônios/metabolismo , Feromônios/farmacologia
11.
J Math Biol ; 85(3): 28, 2022 Sep 13.
Artigo em Inglês | MEDLINE | ID: mdl-36098821

RESUMO

We propose a mathematical model, namely a reaction-diffusion system, to describe social behaviour of cockroaches. An essential new aspect in our model is that the dispersion behaviour due to overcrowding effect is taken into account as a counterpart to commonly studied aggregation. This consideration leads to an intriguing new phenomenon which has not been observed in the literature. Namely, due to the competition between aggregation towards areas of higher concentration of pheromone and dispersion avoiding overcrowded areas, the cockroaches aggregate more at the transition area of pheromone. Moreover, we also consider the fast reaction limit where the switching rate between active and inactive subpopulations tends to infinity. By utilising improved duality and energy methods, together with the regularisation of heat operator, we prove that the weak solution of the reaction-diffusion system converges to that of a reaction-cross-diffusion system.


Assuntos
Baratas , Animais , Difusão , Modelos Teóricos , Feromônios , Comportamento Social
12.
Int J Mol Sci ; 23(15)2022 Jul 30.
Artigo em Inglês | MEDLINE | ID: mdl-35955589

RESUMO

Sirex noctilio Fabricius (Hymenoptera Siricidae) is a major quarantine pest responsible for substantial economic losses in the pine industry. To achieve better pest control, (Z)-3-decen-ol was identified as the male pheromone and used as a field chemical trapping agent. However, the interactions between odorant-binding proteins (OBPs) and pheromones are poorly described. In this study, SnocOBP9 had a higher binding affinity with Z3D (Ki = 1.53 ± 0.09 µM) than other chemical ligands. Molecular dynamics simulation and binding mode analysis revealed that several nonpolar residues were the main drivers for hydrophobic interactions between SnocOBP9 and Z3D. Additionally, computational alanine scanning results indicated that five amino acids (MET54, PHE57, PHE71, PHE74, LEU116) in SnocOBP9 could potentially alter the binding affinity to Z3D. Finally, we used single-site-directed mutagenesis to substitute these five residues with alanine. These results imply that the five residues play crucial roles in the SnocOBP9-Z3D complex. Our research confirmed the function of SnocOBP9, uncovered the key residues involved in SnocOBP9-Z3D interactions, and provides an inspiration to improve the effects of pheromone agent traps.


Assuntos
Himenópteros , Receptores Odorantes , Alanina/metabolismo , Animais , Proteínas de Insetos/genética , Proteínas de Insetos/metabolismo , Masculino , Feromônios/metabolismo , Ligação Proteica , Receptores Odorantes/metabolismo
13.
Comput Intell Neurosci ; 2022: 8740978, 2022.
Artigo em Inglês | MEDLINE | ID: mdl-36035854

RESUMO

People's lives are undergoing tremendous changes with the development of the times. Compared with the past, people's pursuit of spiritual and cultural life also makes our education field usher in a huge development to adapt to the changes in the context of the times. But, at the same time, the development of labor education is gradually being downplayed by people, resulting in a series of problems such as people preferring comfort and not working. Aiming at this common problem, this paper will use the ant colony algorithm and particle swarm optimization algorithm in the computer intelligent algorithm to optimize the way of labor education. It includes the principle and basic process of the ant colony algorithm, the establishment of the mathematical model of the original ant colony algorithm, and the improved algorithm of the ant colony algorithm. The research results of the optimization method of labor education showed the following: when the number of ant colonies reaches 51, the number of iterations of the algorithm will be the least, and the corresponding shortest path is also the best solution; when the combination of pheromone intensity and volatility factor is 3, the optimal solution can be quickly found, and the algorithm inflection point of MMAS is 44.82. From the research results, it can be seen that the computer intelligent algorithm has a good choice for the optimization of labor education and can achieve a major breakthrough in the traditional model of labor education.


Assuntos
Algoritmos , Modelos Teóricos , Simulação por Computador , Computadores , Humanos , Feromônios
14.
PLoS One ; 17(8): e0270532, 2022.
Artigo em Inglês | MEDLINE | ID: mdl-36018860

RESUMO

Halyomorpha halys (Hemiptera: Pentatomidae), an important agricultural and nuisance pest, is highly invasive with peculiar hiding behavior in human-made structures for overwintering. To evaluate the contamination risk of overwintering H. halys in non-agricultural export goods, we conducted a two-year field survey in Republic of Korea to locate overwintering H. halys in two major ports of export, Ulsan and Pyeongtaek ports, and monitored both active and overwintering H. halys population levels with varying distances from the ports ranging from 1 km to 48 km. First, we deployed wooden shelters in the two ports to catch dispersing H. halys for overwintering and conducted visual inspections for human-made structures in the ports to locate overwintering H. halys. In addition, we sampled dead trees to find overwintering H. halys in wooded areas. Second, we monitored active H. halys populations using pheromone traps with varying distances from the ports. From the survey of overwintering populations, no H. halys was collected from wooden shelters deployed in the two ports. However, we found four adults overwintering in human-made structures in Pyeongtaek port in the first year of survey. One dead adult was also found from a dead tree located in a wooded area adjacent to Pyeongtaek port in the second year. For active populations, results of pheromone trapping indicated that H. halys populations were present during autumn dispersal period not only in agricultural areas, but also in wooded areas adjacent to the two ports. This study reports for the first time that overwintering H. halys were found from the inside the port of export in its native areas with a low density. The results were discussed for evaluating contamination risk of overwintering H. halys in export goods shipping from the Republic of Korea.


Assuntos
Heterópteros , Animais , Feromônios , República da Coreia , Árvores
15.
FEMS Microbiol Lett ; 369(1)2022 Sep 20.
Artigo em Inglês | MEDLINE | ID: mdl-36029515

RESUMO

Many plant roots associate with fungi to form mycorrhizae; tree roots especially associate with ectomycorrhizal fungi, such as Tricholoma species. Tricholoma matsutake is an economically important fungus in Asian countries and usually inhabits forests primarily composed of Pinus densiflora (Japanese red pine). In this study, to understand the mycorrhizal association between T. matsutake and P. densiflora, genes specifically expressed in mycorrhiza compared with those expressed in mycelia and fruiting bodies were identified by RNA-seq. This revealed that genes for chromatin, proteasomes, signal transduction, pheromones, cell surface receptors, cytoskeleton, RNA processing and transporters from T. matsutake were highly expressed in mycorrhiza. It also identified 35 mycorrhiza-induced small secreted proteins (MiSSPs) that were highly expressed in mycorrhiza. Meanwhile, genes for proteases, defence-related proteins, cell-wall degradation, signal transduction, pinene synthesis, plant hormones and transporters from P. densiflora were highly expressed in mycorrhiza. These genes may be involved in mycorrhizal formation and maintenance. A MiSSP, 1460819, was highly expressed in mycorrhiza, and this expression was maintained for 24 months. These results provide insight into the mycorrhizal association between T. matsutake and P. densiflora.


Assuntos
Micorrizas , Pinus , Tricholoma , Agaricales , Cromatina , Micorrizas/genética , Peptídeo Hidrolases , Feromônios , Pinus/microbiologia , Reguladores de Crescimento de Plantas , Tricholoma/genética
16.
J Bacteriol ; 204(9): e0017622, 2022 Sep 20.
Artigo em Inglês | MEDLINE | ID: mdl-35938850

RESUMO

Cell-cell signaling mediated by Rgg-family transcription factors and their cognate pheromones is conserved in Firmicutes, including all streptococci. In Streptococcus pyogenes, or group A strep (GAS), one of these systems, the Rgg2/3 quorum sensing (QS) system, has been shown to regulate phenotypes, including cellular aggregation and biofilm formation, lysozyme resistance, and macrophage immunosuppression. Here, we show the abundance of several secreted virulence factors (streptolysin O, SpyCEP, and M protein) decreases upon induction of QS. The main mechanism underlying the changes in protein levels appears to be transcriptional, occurs downstream of the QS circuit, and is dysregulated by the deletion of an Rgg2/3 QS-regulated major facilitator superfamily (MFS) transporter. Additionally, we identify this MFS transporter as the factor responsible for a previously observed increase in aminoglycoside sensitivity in QS-induced cells. IMPORTANCE The production of virulence factors is a tightly regulated process in bacterial pathogens. Efforts to elucidate the mechanisms by which genes are regulated may advance the understanding of factors influencing pathogen behavior or cellular physiology. This work finds expression of a major facilitator superfamily (MFS) transporter, which is governed by a quorum sensing (QS) system, impacts the expression of multiple virulence factors and accounts for QS-dependent antibiotic susceptibility. Although the mechanism underlying this effect is not clear, MFS orthologs with high sequence similarity from S. pneumoniae and S. porcinus were unable to substitute indicating substrate specificity of the GAS MFS gene. These findings demonstrate novel associations between expression of a transmembrane transporter and virulence factor expression and aminoglycoside transport.


Assuntos
Percepção de Quorum , Infecções Estreptocócicas , Aminoglicosídeos/farmacologia , Antibacterianos/farmacologia , Regulação Bacteriana da Expressão Gênica , Humanos , Proteínas de Membrana Transportadoras/genética , Proteínas de Membrana Transportadoras/metabolismo , Muramidase/metabolismo , Feromônios/metabolismo , Percepção de Quorum/fisiologia , Fatores de Transcrição/metabolismo , Fatores de Virulência/genética
17.
Life Sci Alliance ; 5(10)2022 10.
Artigo em Inglês | MEDLINE | ID: mdl-35985794

RESUMO

Yeast use the G-protein-coupled receptor signaling pathway to detect and track the mating pheromone. The G-protein-coupled receptor pathway is inhibited by the regulator of G-protein signaling (RGS) Sst2 which induces Gα GTPase activity and inactivation of downstream signaling. G-protein signaling activates the MAPK Fus3, which phosphorylates the RGS; however, the role of this modification is unknown. We found that pheromone-induced RGS phosphorylation peaks early; the phospho-state of RGS controls its localization and influences MAPK spatial distribution. Surprisingly, phosphorylation of the RGS promotes completion of cytokinesis before pheromone-induced growth. Completion of cytokinesis in the presence of pheromone is promoted by the kelch-repeat protein, Kel1 and antagonized by the formin Bni1. We found that RGS complexes with Kel1 and prefers the unphosphorylatable RGS mutant. We also found overexpression of unphosphorylatable RGS exacerbates cytokinetic defects, whereas they are rescued by overexpression of Kel1. These data lead us to a model where Kel1 promotes completion of cytokinesis before pheromone-induced polarity but is inhibited by unphosphorylated RGS binding.


Assuntos
Citocinese , Proteínas Quinases Ativadas por Mitógeno , Proteínas RGS , Proteínas de Saccharomyces cerevisiae , Citocinese/genética , Proteínas de Ligação ao GTP/metabolismo , Proteínas Ativadoras de GTPase , Proteínas dos Microfilamentos/metabolismo , Proteínas Quinases Ativadas por Mitógeno/metabolismo , Feromônios/metabolismo , Fosforilação , Proteínas RGS/metabolismo , Receptores Acoplados a Proteínas G/metabolismo , Saccharomyces cerevisiae/metabolismo , Proteínas de Saccharomyces cerevisiae/genética , Proteínas de Saccharomyces cerevisiae/metabolismo
18.
Arthropod Struct Dev ; 70: 101201, 2022 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-35994811

RESUMO

The soldier caste of termites uses sensilla to sense pheromonal, tactile, and vibrational cues to communicate inside and outside their nest. Although sensilla with many modalities on the antennae of subterranean termites have been well explored, there remains a lack of information regarding sensillum characteristics and distribution of the nonolfactory organs of the soldier caste in the Coptotermes genus. In this study, the ultrastructure of sensilla from the soldier caste of three Coptotermes spp. (Coptotermes formosanus, Coptotermes curvignathus, and Coptotermes gestroi) was observed by scanning and transmission electron microscopy, and the putative function of each type was deduced. Six total sensillum types were observed, with two mechanoreceptive sensillum types (hair and plate). The long flexible-peg mechanoreceptive sensilla may work as contact-chemoreceptive sensilla due to their elongated dendritic outer segments and uniporous characteristics. There was a significant depletion of mechano-chemoreceptive sensillum numbers in C. gestroi, which was compensated by a high density of short-peg mechanoreceptive sensilla on the pronotum. Finally, cuticular and innervation characteristics of thermo-/hygrosensitive sensilla were observed for the first time on the labrum of the soldier caste of Coptotermes.


Assuntos
Isópteros , Animais , Microscopia Eletrônica de Varredura , Feromônios , Sensilas/ultraestrutura , Células Receptoras Sensoriais , Classe Social
19.
Behav Processes ; 201: 104729, 2022 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-35934233

RESUMO

In complex terrestrial environments, chemical signals can be the most important sensory modality for locating conspecifics for potential mating opportunities, especially in spatially segregated populations or habitats. Organisms must evolve chemical signals to maximize the efficacy of conveying information, particularly in creating trails or mate-choice cues. Long-distance transmission of chemical signals may be an increasingly important management concern for small and fractured populations or potentially threatened species, such as gopher tortoises in the southeastern U.S. Mental gland secretions have been shown to have pheromonal function in gopher tortoises, suggesting a potential role as trail or marking pheromones, allowing males to track females or other males to find females. In this study, male gopher tortoises were given paired presentations of a negative control (distilled water) with serial dilutions (1:4, 1:20, 1:100, and 1:500) of male mental gland secretions. Male tortoises were able to discern treatment differences up to 1:20 diluted secretions, responding with an array of social behaviors (e.g. for the 1:20 dilution trial, carapace alignment and head bobbing occurred more frequently for the mental gland secretion relative to the control; p < 0.01). Multivariate principal components analysis yielded PC1 (including, approach, carapace alignment, head bobbing, tasting air, sniffing, and doubleback) that differed by treatment (p = 0.0007) and also was higher for the 1:20 diluted presentation relative to the 1:500 diluted presentation (p = 0.04). This study provides insight into gopher tortoise ecology, mate-choice, and the utility of environmentally diluted mental gland secretions in the external environment when seeking mating opportunities.


Assuntos
Geômis , Tartarugas , Animais , Ecossistema , Espécies em Perigo de Extinção , Feminino , Masculino , Feromônios/farmacologia , Tartarugas/fisiologia
20.
J Exp Biol ; 225(15)2022 08 01.
Artigo em Inglês | MEDLINE | ID: mdl-35942527

RESUMO

We used a robotic gantry to test the hypothesis that tandem running in the ant Temnothorax albipennis can be successful in the absence of trail laying by the leader. Pheromone glands were placed on a pin attached to a gantry. This set-up substituted for the leader of a tandem run. Neither the pin nor the glands touched the substrate and thus the ant following the robot was tracking a plume of airborne pheromones. The robot led individual workers from their current nest to a potential new one. The robotic gantry was programmed to allow for human intervention along its path to permit the following ant to stop and survey its surroundings and then catch up with its mechanical leader. The gantry then automatically tracked the precise route taken by each ant from the new nest back to the old one. Ants led by the robot were significantly more successful at finding their way home than those we carried to the new nest that had no opportunity to learn landmarks. The robot was programmed to take either a straight or a sinusoidal path to the new nest. However, we found no significant difference in the abilities of ants that had been led on such direct or sinuous paths to find their way home. Here, the robot laid no trail but our findings suggest that, under such circumstances, the following ant may lay a trail to substitute for the missing one.


Assuntos
Formigas , Procedimentos Cirúrgicos Robóticos , Robótica , Animais , Comunicação , Humanos , Feromônios
SELEÇÃO DE REFERÊNCIAS
DETALHE DA PESQUISA
...