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1.
Insects ; 15(3)2024 Mar 01.
Artigo em Inglês | MEDLINE | ID: mdl-38535365

RESUMO

"Calling behaviour" is a stereotyped rhythmic motor pattern displayed by female moths, by which they emit the sex pheromone to attract of conspecific males. Calling occurs through a squeezing mechanism based on the turtleneck-like folding and unfolding of the ovipositor cuticle during its telescopic extensions and retractions. This mechanism is under the control of the terminal abdominal ganglion (TAG). By combining anatomical and electrophysiological approaches, here we studied the morpho-functional organisation of the abdominal muscles and the activity of motoneurons from TAG nerve N4-N6 as correlated to the ovipositor movements during calling in the female spongy moth Lymantria dispar. Our results show that the three abdominal segments S7, S8 and S9 (ovipositor) are highly specialized structures containing cuticular appendages, hinges, apodemes and several large muscles, innervated by N4 and especially by N5. N6 mainly innervates the oviductal tract. We also identified a number of motor units from N4 and N5, the spike activity of which is correlated with the ovipositor movements during calling. In conclusion, the release of sex pheromones in the female spongy moth is obtained by extensions and retractions of the ovipositor operated by a coordinated motor program, which is mainly sustained by the activity of a few motor units under the control of TAG nerves N4 and N5.

2.
Life (Basel) ; 13(7)2023 Jul 05.
Artigo em Inglês | MEDLINE | ID: mdl-37511884

RESUMO

Sea urchins rely on chemical senses to localize suitable food resources, therefore representing model species for chemosensory studies. In the present study, we investigated the chemical sensitivity of the Mediterranean sea urchin Paracentrotus lividus to the blue-green alga Aphanizomenon flos-aquae, namely "Klamath", and to a few amino acids chosen from the biochemical composition of the same algae. To this end, we used the "urchinogram" method, which estimates the movement rate of the sea urchins in response to chemicals. Our results showed that Klamath represents a strong chemical stimulus for P. lividus as it elicits an overall movement of spines, pedicellariae, and tube feet coupled, in some cases, to a coordinated locomotion of the animals. Sea urchins also displayed a sensitivity, even if to a lesser extent, to leucine, threonine, arginine, and proline, thus implying that the amino acids contained in Klamath may account, at least in part, for the stimulating effects exerted by the whole algae. Additionally, our results show that Klamath, as well as spirulina, another blue-green alga with high nutritional value, is very attractive for this sea urchin species. These findings gain further importance considering the potential profit of echinoderms for commercial consumers and their growing role in aquaculture. Klamath and spirulina combine high nutritional profiles with attractive and stimulating abilities and may be considered potential valuable feed supplements in sea urchin aquaculture.

3.
Nutrients ; 15(11)2023 May 26.
Artigo em Inglês | MEDLINE | ID: mdl-37299455

RESUMO

Physical activities seem to counteract the age-related physiological decline of the olfactory function which, influencing the food choices and eating behavior, can affect the body weight of individuals. The main purpose of this cross-sectional study was to evaluate the relationships between olfactory function and BMI in female and male Elderly Subjects (ES), according to the level of their lifestyle activities in physical, cognitive, and social terms. Considering weekly physical activities, the adult elderlies who decided to participate in this study were divided into active ES (n = 65) and non-active ES (n = 68). Assessment of weekly activities and olfactory function were performed by means of face-to-face interviews and the "Sniffin' Sticks" battery test, respectively. The results show that ES who are overweight and with a non-active lifestyle achieved lower TDI olfactory scores than normal weight ES and those classified as active. Hyposmic and non-active ES showed a higher BMI than normosmic and active ES. Sex-related differences, with females performing better than males, were evident in the presence of at least one of the following conditions: non-activity, hyposmia, or overweight. Inverse correlations were found between BMI and TDI olfactory score and between BMI and hours/week spent on physical activities, both when subjects were considered all together and when they were divided into females and males. These findings suggest that a higher BMI is related to the olfactory dysfunction linked to active or non-active lifestyle and the sex-related differences, and the condition of hyposmia is related to the increase in body weight due to lifestyle and sex differences. Given that the relationship between BMI and non-exercise physical activities is comparable to that between BMI and exercise physical activities, and this may be of particular importance for ES with limited mobility.


Assuntos
Transtornos do Olfato , Adulto , Humanos , Masculino , Feminino , Idoso , Estudos Transversais , Anosmia , Odorantes , Sobrepeso , Índice de Massa Corporal , Limiar Sensorial/fisiologia , Olfato/fisiologia , Peso Corporal
4.
Metabolites ; 13(2)2023 Jan 30.
Artigo em Inglês | MEDLINE | ID: mdl-36837824

RESUMO

Obesity is a severe health problem linked to an increased risk of comorbidity and mortality and its etiopathogenesis includes genetic, epigenetic, microbiota composition, and environmental factors, such as dietary habits. The olfactory system plays an important role in controlling food intake and meal size, influencing body weight and energy balance. This study aims to identify the connection between olfactory function and clinical and nutritional aspects related to weight excess in a group of 68 patients with overweight or obesity. All participants underwent the evaluation of olfactory function, anthropometric data (weight, height, BMI, waist circumference), clinical data (hypertension, disglycemia, dyslipidemia, metabolic syndrome), and adherence to the Mediterranean diet (Mediterranean Diet Score). A fourth-generation artificial neural network data mining approach was used to uncover trends and subtle associations between variables. Olfactory tests showed that 65% of patients presented hyposmia. A negative correlation was found between olfactory scores and systolic blood pressure, fasting plasma glucose, and triglycerides levels, but a positive correlation was found between olfactory scores and the Mediterranean diet score. The methodology of artificial neural networks and the semantic connectivity map "Auto-Contractive Map" highlighted the underlying scheme of the connections between the variables considered. In particular, hyposmia was linked to obesity and related metabolic alterations and the male sex. The female sex was connected with normosmia, higher adherence to the Mediterranean diet, and normal values of blood pressure, lipids, and glucose levels. These results highlight an inverse correlation between olfactory skills and BMI and show that a normosmic condition, probably because of greater adherence to the Mediterranean diet, seems to protect not only from an excessive increase in body weight but also from associated pathological conditions such as hypertension and metabolic syndrome.

5.
Comput Struct Biotechnol J ; 21: 1054-1065, 2023.
Artigo em Inglês | MEDLINE | ID: mdl-38213886

RESUMO

Several studies were focused on the genetic ability to taste the bitter compound 6-n-propylthiouracil (PROP) to assess the inter-individual taste variability in humans, and its effect on food predilections, nutrition, and health. PROP taste sensitivity and that of other chemical molecules throughout the body are mediated by the bitter receptor TAS2R38, and their variability is significantly associated with TAS2R38 genetic variants. We recently automatically identified PROP phenotypes with high precision using Machine Learning (mL). Here we have used Supervised Learning (SL) algorithms to automatically identify TAS2R38 genotypes by using the biological features of eighty-four participants. The catBoost algorithm was the best-suited model for the automatic discrimination of the genotypes. It allowed us to automatically predict the identification of genotypes and precisely define the effectiveness and impact of each feature. The ratings of perceived intensity for PROP solutions (0.32 and 0.032 mM) and medium taster (MT) category were the most important features in training the model and understanding the difference between genotypes. Our findings suggest that SL may represent a trustworthy and objective tool for identifying TAS2R38 variants which, reducing the costs and times of molecular analysis, can find wide application in taste physiology and medicine studies.

6.
Nutrients ; 14(23)2022 Nov 24.
Artigo em Inglês | MEDLINE | ID: mdl-36501016

RESUMO

Smell strongly contributes to food choice and its hedonistic evaluation. A reduction or loss of smell has been related to malnutrition problems, resulting in excessive weight loss or gain. Voltage-gated potassium channels Kv1.3 are widely expressed in the olfactory bulb, and contribute mainly to the value of the resting membrane potential and to the frequency of action potentials. Mutations in the Kv1.3 gene are associated with alterations in glycemic homeostasis and olfactory sensitivity. We evaluated the olfactory performance in 102 healthy subjects and its association with BMI and polymorphism in the human Kv1.3 gene. Olfactory performance, based on the olfactory threshold, discrimination and identification scores and their summed score (TDI), was measured using the "Sniffin' Sticks" test. Subjects were genotyped for the rs2821557 polymorphism of the Kv1.3 gene, whose major allele T was associated with a super-smeller phenotype, lower plasma glucose levels and resistance to diet-induced obesity as compared with the minor allele C. Based on the Kv1.3 genotype, the TDI and I olfactory scores obtained by the subjects were the following: TT > TC > CC. Subjects who were TT homozygous or heterozygous exhibited lower BMIs and reached higher olfactory scores than those with the CC genotype. The results were sex-dependent: heterozygous females performed better than heterozygous males. These findings show an inverse relationship between olfactory function and BMI, and a significant effect of the Kv1.3 genotypes on the olfactory functions and on the BMIs of the subjects. Finally, they suggest that the sex-related differences in the olfactory function can be partially ascribed to the Kv1.3 gene's polymorphism.


Assuntos
Canais de Potássio de Abertura Dependente da Tensão da Membrana , Masculino , Feminino , Humanos , Índice de Massa Corporal , Olfato/genética , Bulbo Olfatório , Potenciais da Membrana/genética
7.
Phytother Res ; 36(7): 2803-2823, 2022 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-35485365

RESUMO

Overweight and obesity are constantly increasing, not only in Western countries but also in low-middle-income ones. The decrease of both the intake of carbohydrates and their assimilation are among the main dietary strategies to counter these conditions. α-Amylase, a key enzyme involved in the digestion of carbohydrates, is the target enzyme to reduce the absorption rate of carbohydrates. α-Amylase inhibitors (α-AIs) can be found in plants. The common bean, Phaseolus vulgaris is of particular interest due to the presence of protein-based α-AIs which, through a protein-protein interaction, reduce the activity of this enzyme. Here we describe the nature of the various types of common bean seed extracts, the type of protein inhibitors they contain, reviewing the recent Literature about their molecular structure and mechanism of action. We also explore the existing evidence (clinical trials conducted on both animals and humans) supporting the potential benefits of this protein inhibitors from P. vulgaris, also highlighting the urgent need of further studies to confirm the clinical efficacy of the commercial products. This work could contribute to summarize the knowledge and application of P. vulgaris extract as a nutraceutical strategy for controlling unwanted weight gains, also highlighting the current limitations.


Assuntos
Diabetes Mellitus , Inibidores Enzimáticos , Obesidade , Phaseolus , alfa-Amilases , Animais , Carboidratos , Diabetes Mellitus/tratamento farmacológico , Suplementos Nutricionais , Inibidores Enzimáticos/uso terapêutico , Humanos , Obesidade/tratamento farmacológico , Phaseolus/química , alfa-Amilases/antagonistas & inibidores
8.
Behav Brain Res ; 427: 113860, 2022 06 03.
Artigo em Inglês | MEDLINE | ID: mdl-35341882

RESUMO

Among the factors that contribute to the physiological variability of the olfactory function of individuals, an important role seems to be played by the OBPs present in the mucus that bathes the ciliated terminals of the olfactory sensory neurons, facilitating the access of odorants to the olfactory receptors. It was recently highlighted that the rs2590498 polymorphism in the odor binding-protein (OBPIIa) gene it is associated with the olfactory threshold in healthy individuals. Aim of this study was to evaluate: 1) the presence of a relationship between the threshold olfactory performance of healthy subjects and the intensity with which they perceive the smelled odorants, and 2) the effect of the rs2590498 polymorphism of the OBPIIa gene on perceived intensity. We found a positive correlation between threshold olfactory and perceived intensity, and that AA homozygous subjects reported a perceived intensity higher than heterozygous and GG homozygous subjects. By showing a positive effect of the rs2590498 polymorphism of the hOBPIIa gene on the intensity perceived, these results suggest that it allows a larger number of molecules in an odorous mixture to reach the olfactory receptors.


Assuntos
Neurônios Receptores Olfatórios , Receptores Odorantes , Humanos , Odorantes , Polimorfismo Genético/genética , Receptores Odorantes/genética , Olfato/fisiologia
9.
Nutrients ; 14(6)2022 Mar 16.
Artigo em Inglês | MEDLINE | ID: mdl-35334919

RESUMO

Smell plays a critical role in food choice and intake by influencing energy balance and body weight. Malnutrition problems or modified eating behaviors have been associated with olfactory impairment or loss. The obesity epidemic is a serious health problem associated with an increased risk of mortality and major physical comorbidities. The etiopathogenesis of obesity is complex and multifactorial, and one of the main factors contributing to the rapid increase in its incidence is the environment in which we live, which encourages the overconsumption of foods rich in energy, such as saturated fats and sugars. By means of the "Sniffin' Sticks" test, we measured the olfactory threshold, discrimination and identification score (TDI score) in patients of the Obesity Center of the University Hospital (OC; n = 70) and we compared them with that of healthy normal weight controls (HC; n = 65). OC patients demonstrated a significantly lower olfactory function than HC subjects both general and specific for the ability to discriminate and identify odors, even when they were considered separately as females and males. For OC patients, a negative correlation was found between body mass index (BMI) and olfactory scores obtained by each subject, both when they were divided according to gender and when they were considered all together. Besides, normosmic OC patients showed a significantly lower BMI than hyposmic ones. A reduced sense of smell may contribute to obesity involving the responses of the cephalic phase, with a delay in the achievement of satiety and an excessive intake of high-energy foods and drinks.


Assuntos
Sobrepeso , Olfato , Índice de Massa Corporal , Feminino , Voluntários Saudáveis , Humanos , Masculino , Obesidade/complicações , Sobrepeso/complicações , Olfato/fisiologia
10.
Nutrients ; 14(2)2022 Jan 07.
Artigo em Inglês | MEDLINE | ID: mdl-35057433

RESUMO

Several studies have used taste sensitivity to 6-n-propylthiouracil (PROP) to evaluate interindividual taste variability and its impact on food preferences, nutrition, and health. We used a supervised learning (SL) approach for the automatic identification of the PROP taster categories (super taster (ST); medium taster (MT); and non-taster (NT)) of 84 subjects (aged 18-40 years). Biological features determined from subjects were included for the training system. Results showed that SL enables the automatic identification of objective PROP taster status, with high precision (97%). The biological features were classified in order of importance in facilitating learning and as prediction factors. The ratings of perceived taste intensity for PROP paper disks (50 mM) and PROP solution (3.2 mM), along with fungiform papilla density, were the most important features, and high estimated values pushed toward ST prediction, while low values leaned toward NT prediction. Furthermore, TAS2R38 genotypes were significant features (AVI/AVI, PAV/PAV, and PAV/AVI to classify NTs, STs, and MTs, respectively). These results, in showing that the SL approach enables an automatic, immediate, scalable, and high-precision classification of PROP taster status, suggest that it may represent an objective and reliable tool in taste physiology studies, with applications ranging from basic science and medicine to food sciences.


Assuntos
Preferências Alimentares , Estado Nutricional , Propiltiouracila , Papilas Gustativas/anatomia & histologia , Paladar/fisiologia , Adulto , Feminino , Preferências Alimentares/classificação , Preferências Alimentares/fisiologia , Genótipo , Saúde , Humanos , Masculino , Polimorfismo de Nucleotídeo Único , Análise de Componente Principal , Curva ROC , Receptores Acoplados a Proteínas G/genética , Aprendizado de Máquina Supervisionado , Paladar/genética , Papilas Gustativas/fisiologia , Percepção Gustatória , Adulto Jovem
11.
J Exp Biol ; 224(23)2021 12 01.
Artigo em Inglês | MEDLINE | ID: mdl-34761803

RESUMO

The integration of sensory information with adequate motor outputs is critical for animal survival. Here, we present an innovative technique based on a non-invasive closed-circuit device consisting of a perfusion/stimulation chamber chronically applied on a single leg of the crayfish Procambarus clarkii. Using this technique, we focally stimulated the leg inside the chamber and studied the leg-dependent sensory-motor integration involving other sensory appendages, such as antennules and maxillipeds, which remain unstimulated outside the chamber. Results show that the stimulation of a single leg with chemicals, such as disaccharides, is sufficient to trigger a complex search behaviour involving locomotion coupled with the reflex activation of antennules and maxillipeds. This technique can be easily adapted to other decapods and/or other sensory appendages. Thus, it has opened possibilities for studying sensory-motor integration evoked by leg stimulation in whole aquatic animals under natural conditions to complement, with a direct approach, current ablation or silencing techniques.


Assuntos
Astacoidea , Células Quimiorreceptoras , Animais , Extremidades , Perna (Membro) , Locomoção , Reflexo
12.
Front Aging Neurosci ; 13: 695115, 2021.
Artigo em Inglês | MEDLINE | ID: mdl-34504418

RESUMO

Objective: This cross-sectional study evaluates the impact of active or non-active lifestyle in terms of physical, cognitive and social activity on the olfactory function in Elderly Subjects (ES) and aims at looking for a correlation between the time devoted to life activities and the score obtained during the olfactory tests by each individual. Methods: One hundred and twenty-two elderly volunteers were recruited in Sardinia (Italy) and divided into active ES (n = 60; 17 men, 43 women; age 67.8 ± 1.12 years) and inactive ES (n = 62; 21 men, 41 women, age 71.1 ± 1.14 years) based on their daily physical activities. The olfactory function was evaluated using the "Sniffin's Sticks" battery test, while the assessment of daily activities was made by means of personal interviews. Results: A significant effect of active or inactive lifestyle was found on the olfactory function of ES (F (1,120) > 10.16; p < 0.005). A positive correlation was found between the olfactory scores and the number of hours per week dedicated to physical activities (Pearson's r > 0.32, p ≤ 0.014) in both active and inactive ES. Conclusions: High levels of exercise and non-exercise physical activity are strongly associated with the olfactory function and, consequently, with the quality of life of the elderly. Given the limited physical exercise of elderly people, they can benefit from a more active lifestyle by increasing non-exercise physical activities.

13.
J Insect Physiol ; 131: 104240, 2021.
Artigo em Inglês | MEDLINE | ID: mdl-33845094

RESUMO

In recent years, there has been interest in reduced-risk materials with insecticidal properties for the invasive pest spotted-wing drosophila, Drosophila suzukii. Here, we compared the peripheral sensitivity (via the tip-recording technique, used to monitor the neural activity of gustatory receptor neurons [GRNs]) and palatability (via the Proboscis Extension Reflex [PER]) of chitosan, a polysaccharide derived from chitin, with that of erythritol, a sugar alcohol, to male and female D. suzukii. Because in some insect species it has previously been shown that chitosan has some insecticidal properties, then treatment effects on mortality rates of male and female D. suzukii were quantified. Physiological recordings from the l-type labellar sensilla showed that erythritol evoked responses from one GRN, while chitosan elicited spiked activity from a second one. The first PER bioassay revealed that the level of response to erythritol increased significantly for males and females as the concentrations increased, and the effect of fly sex was non-significant. The second PER bioassay compared the male and female response to chitosan and erythritol each at 0.125, 0.25, 0.5, 1, and 2% concentrations. The overall female PER to erythritol was significantly greater than that exhibited by males, and no differences were noted between sexes when chitosan was evaluated. These results indicate that chitosan alone can elicit PER responses in adult D. suzukii. In the third experiment, chitosan was toxic to D. suzukii. When combined with sucrose (2%), chitosan elicited high levels (80-100%) of mortality of adult D. suzukii within 3 days, particularly in males. The presence of erythritol did not seem to increase the toxic effect of chitosan.


Assuntos
Células Quimiorreceptoras/efeitos dos fármacos , Quitosana/farmacologia , Drosophila/efeitos dos fármacos , Eritritol/farmacologia , Controle de Insetos/métodos , Animais , Comportamento Alimentar/efeitos dos fármacos , Feminino , Masculino , Testes de Toxicidade
14.
Molecules ; 26(8)2021 Apr 13.
Artigo em Inglês | MEDLINE | ID: mdl-33924512

RESUMO

Taste plays an important role in processes such as food choices, nutrition status and health. Salivary proteins contribute to taste sensitivity. Taste reduction has been associated with obesity. Gender influences the obesity predisposition and the genetic ability to perceive the bitterness of 6-n-propylthiouracil (PROP), oral marker for food preferences and consumption. We investigated variations in the profile of salivary proteome, analyzed by HPLC-ESI-MS, between sixty-one normal weight subjects (NW) and fifty-seven subjects with obesity (OB), based on gender and PROP sensitivity. Results showed variations of taste-related salivary proteins between NW and OB, which were differently associated with gender and PROP sensitivity. High levels of Ps-1, II-2 and IB-1 proteins belonging to basic proline rich proteins (bPRPs) and PRP-1 protein belonging to acid proline rich proteins (aPRPs) were found in OB males, who showed a lower body mass index (BMI) than OB females. High levels of Ps-1 protein and Cystatin SN (Cyst SN) were found in OB non-tasters, who had lower BMI than OB super-tasters. These new insights on the role of salivary proteins as a factor driving the specific weight gain of OB females and super-tasters, suggest the use of specific proteins as a strategic tool modifying taste responses related to eating behavior.


Assuntos
Propiltiouracila , Proteínas e Peptídeos Salivares/análise , Paladar/fisiologia , Adulto , Idoso , Índice de Massa Corporal , Feminino , Genótipo , Humanos , Masculino , Pessoa de Meia-Idade , Obesidade , Adulto Jovem
15.
Nutrients ; 13(2)2021 Feb 22.
Artigo em Inglês | MEDLINE | ID: mdl-33671721

RESUMO

Smell strongly contributes to food choice and intake, influencing energy balance and body weight; its reduction or loss has been related to malnutrition problems. Some patients with inflammatory bowel disease (IBD), mainly Crohn's disease (CD) and ulcerative colitis (UC), are underweight, while others are overweight. Some studies suggest that changes in eating habits could be linked to specific disorders of the olfactory functions. We assessed the olfactory performance in 199 subjects (healthy control (HC) n = 99, IBD n = 100), based on the olfactory Threshold, Discrimination and Identification score (TDI score), measured with the "Sniffin' Sticks" test. Subjects were genotyped for the rs2590498 polymorphism of the OBPIIa gene. IBD patients showed both a slightly, but significantly, lower olfactory function and a higher BMI compared to HC subjects. Threshold (in both population) and Discrimination (in IBD patients) olfactory score were affected by the OBPIIa genotype. BMI was influenced by both health status and OBPIIa genotype. A lower olfactory function may delay the satiety sensation and thus increase meal duration and body weight in IBD patients. However, the AA genotype of the OBPIIa seems to "protect" IBD patients from more severe olfactory dysfunction.


Assuntos
Índice de Massa Corporal , Doenças Inflamatórias Intestinais/metabolismo , Polimorfismo Genético , Receptores Odorantes/genética , Olfato/fisiologia , Estudos de Casos e Controles , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Odorantes , Limiar Sensorial , Olfato/genética
16.
Behav Brain Res ; 402: 113127, 2021 03 26.
Artigo em Inglês | MEDLINE | ID: mdl-33422593

RESUMO

Most odors of foods and drinks are mixtures of molecules. By means of the coupled Gas Chromatography-Olfactometry (GC-O) technique, single components of flavor mixtures can be separated, identified and verbally evaluated by subjects. The number of single molecules smelled by subjects during GC-O analysis (i.e., the number of odor-active compounds) was previously found to be linearly correlated with odor Threshold (T) score. Using the "Sniffin' Sticks" test, the same subjects were classified as normosmic or hyposmic. Hydrophobic odorants are captured and transported through the mucus layer by the odorant binding proteins (OBPs), particularly expressed in the olfactory cleft and associated with the olfactory function. In this study, subjects were genotyped for the rs2590498 (A/G) polymorphism of the OBPIIa gene, whose major allele A is associated with a higher olfactory sensitivity as compared to the minor allele G. One-way ANOVA showed a significant effect of the genotype of the OBPIIa locus on the: a) T score; b) number of odor-active compounds smelled; c) intensity perceived when sniffing the complex odor of banana. In conclusion, the threshold olfactory performance, but also the individual ability to smell single molecules, can be attributed, partly at least, to the rs2590498 polymorphism of the OBPIIa gene.


Assuntos
Anosmia/genética , Lipocalinas/genética , Percepção Olfatória/genética , Limiar Sensorial/fisiologia , Adulto , Cromatografia Gasosa , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Polimorfismo de Nucleotídeo Único
17.
J Insect Physiol ; 125: 104088, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-32652080

RESUMO

Drosophila suzukii is an invasive pest that prefers to lay eggs in ripening fruits, whereas most closely related Drosophila species exclusively use rotten fruit as oviposition site. This behaviour is allowed by an enlarged and serrated ovipositor that can pierce intact fruit skin, and by multiple contact sensory systems (mechanosensation and taste) that detect the optimal egg-laying substrates. Here, we tested the hypothesis that bristles present in the D. suzukii ovipositor tip contribute to these sensory modalities. Analysis of the bristle ultrastructure revealed that four different types of cuticular elements (conical pegs type 1 and 2, chaetic and trichoid sensilla) are present on the tip of each ovipositor plate. All of them have a poreless shaft and are innervated at their base by a single neuron that ends in a distal tubular body, thus resembling mechanosensitive structures. Fluorescent labelling in D. suzukii and D. melanogaster revealed that pegs located on the ventral side of the ovipositor tip are innervated by a single neuron in both species. RNA-sequencing profiled gene expression, notably sensory receptor genes of the terminalia of D. suzukii and of three other Drosophila species with changes in their ovipositor structure (from serrated to blunt ovipositor: Drosophila subpulchrella, Drosophila biarmipes and D. melanogaster). Our results revealed few species-specific transcripts and an overlapping expression of candidate mechanosensitive genes as well as the presence of some chemoreceptor transcripts. These experimental evidences suggest a mechanosensitive function for the D. suzukii ovipositor, which might be crucial across Drosophila species independently from ovipositor shape.


Assuntos
Drosophila/fisiologia , Mecanotransdução Celular/genética , Oviposição/fisiologia , Animais , Drosophila/genética , Drosophila/ultraestrutura , Feminino , Microscopia Eletrônica de Varredura , Microscopia Eletrônica de Transmissão , Oviposição/genética , Sensilas , Especificidade da Espécie , Percepção Gustatória
18.
Nutrients ; 12(7)2020 Jul 07.
Artigo em Inglês | MEDLINE | ID: mdl-32645975

RESUMO

Taste buds containing receptor cells that primarily detect one taste quality provide the basis for discrimination across taste qualities. The molecular receptor multiplicity and the interactions occurring between bud cells encode information about the chemical identity, nutritional value, and potential toxicity of stimuli before transmitting signals to the hindbrain. PROP (6-n-propylthiouracil) tasting is widely considered a marker for individual variations of taste perception, dietary preferences, and health. However, controversial data have been reported. We present measures of the peripheral gustatory system activation in response to taste qualities by electrophysiological recordings from the tongue of 39 subjects classified for PROP taster status. The waveform of the potential variation evoked depended on the taste quality of the stimulus. Direct relationships between PROP sensitivity and electrophysiological responses to taste qualities were found. The largest and fastest responses were recorded in PROP super-tasters, who had the highest papilla density, whilst smaller and slower responses were found in medium tasters and non-tasters with lower papilla densities. The intensities perceived by subjects of the three taster groups correspond to their electrophysiological responses for all stimuli except NaCl. Our results show that each taste quality can generate its own electrophysiological fingerprint on the tongue and provide direct evidence of the relationship between general taste perception and PROP phenotype.


Assuntos
Propiltiouracila/farmacologia , Papilas Gustativas/efeitos dos fármacos , Paladar , Adulto , Dieta/métodos , Fenômenos Eletrofisiológicos , Feminino , Humanos , Masculino , Fenótipo , Cloreto de Sódio/administração & dosagem , Percepção Gustatória/efeitos dos fármacos , Língua/efeitos dos fármacos
19.
Arch Insect Biochem Physiol ; 104(3): e21669, 2020 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-32190926

RESUMO

Drosophila suzukii Matsumura (Diptera: Drosophilidae) is an invasive, destructive crop pest that originated in South East Asia. D. suzukii recently invaded Western countries and is threatening both European and American fruit industries. It is extremely attracted to otherwise undamaged, ripening fruits, unlike most other Drosophila species that attack only decaying or rotten fruits. Recent studies on different insect species showed that several naturally occurring compounds of easy market availability showing deterrent action may be used to supplement mass catches with food traps. Based on these considerations, the aim of the present work was to test the effects of some natural compounds (alone or in the mixture) on the olfactory system of the D. suzukii and the behavioral responses evoked. We measured by electroantennogram (EAG) recordings, the olfactory sensitivity of antennae to increasing concentrations of eugenol, vanillin, menthol, cis-jasmone; eugenol + vanillin, +menthol, +cis-jasmone; vanillin + menthol, +cis-jasmone. In addition, the behavioral responses to the same compounds and mixtures were evaluated. Our electrophysiological results show a dose-response relationship between the EAG amplitudes and the increasing concentrations of the olfactory compound. The behavioral results show that the number of laid eggs is significantly different between the standard diet and the standard diet + natural compound. These results underline a specificity in the olfactory sensitivity and in the ovipositing behavior of D. suzukii females; also, they could be valuable for the identification of key chemicals aimed at the future development of strategies in the management and control of this harmful insect for crops.


Assuntos
Drosophila/efeitos dos fármacos , Oviposição/efeitos dos fármacos , Olfato , Animais , Antenas de Artrópodes/efeitos dos fármacos , Comportamento Animal/efeitos dos fármacos , Benzaldeídos , Ciclopentanos , Relação Dose-Resposta a Droga , Drosophila/fisiologia , Fenômenos Eletrofisiológicos , Eugenol , Comportamento Alimentar , Feminino , Repelentes de Insetos , Mentol , Odorantes , Oxilipinas
20.
Nutrients ; 12(2)2020 Feb 04.
Artigo em Inglês | MEDLINE | ID: mdl-32033224

RESUMO

Inflammatory bowel disease (IBD) is a chronic inflammatory condition of the gastrointestinal tract resulting from interactions among various factors with diet being one of the most significant. IBD-related dietary behaviors are not clearly related to taste dysfunctions. We analyzed body mass index (BMI) and perception of six taste qualities and assessed effects of specific taste genes in IBD patients and healthy subjects (HC). BMI in IBD patients was higher than in HC subjects. Taste sensitivity to taste qualities was reduced in IBD patients, except for sour taste, which was higher than in HC subjects. Genetic variations were related to some taste responses in HC subjects, but not in IBD patients. Frequencies of genotype AA and allele A in CD36 polymorphism (rs1761667) were significantly higher in IBD patients than in HC subjects. The taste changes observed could be explained by the oral pathologies and microbiome variations known for IBD patients and can justify their typical dietary behaviors. The lack of genetic effects on taste in IBD patients indicates that IBD might compromise taste so severely that gene effects cannot be observed. However, the high frequency of the non-tasting form of CD36 substantiates the fact that IBD-associated fat taste impairment may represent a risk factor for IBD.


Assuntos
Antígenos CD36/genética , Anidrases Carbônicas/genética , Doenças Inflamatórias Intestinais/genética , Polimorfismo Genético , Percepção Gustatória/genética , Paladar/genética , Adulto , Índice de Massa Corporal , Estudos de Casos e Controles , Feminino , Frequência do Gene , Genótipo , Humanos , Doenças Inflamatórias Intestinais/complicações , Masculino , Fenótipo , Distúrbios do Paladar/genética
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