Response of summerform pear psylla (Hemiptera: Psyllidae) to male- and female-produced odors

2011 ◽  
Vol 143 (3) ◽  
pp. 245-253 ◽  
Author(s):  
Christelle Guédot ◽  
David R. Horton ◽  
Peter J. Landolt

AbstractWe examined the role of chemical signals in sex attraction of pear psylla, Cacopsylla pyricola (Förster), assessing the response of summerform male and female psyllids to male- and female-produced volatile chemicals. Male psyllids were attracted to odors from live females and pentane extracts of females. Extracts of females were as attractive to males as live females, suggesting that the female-produced volatile chemicals responsible for male attraction might be isolated by extracting females with pentane. Females were not attracted to odorants from live females and tended to avoid odorants from extracts of females. Furthermore, summerform males and females were not attracted or repelled by male-produced odorants from live males or extracts of males. Results of olfactometer assays using male summerform C. pyricola are consistent with results from earlier studies with the winterform morphotype of this species.


Perception ◽  
1995 ◽  
Vol 24 (8) ◽  
pp. 969-973 ◽  
Author(s):  
Edward P Chronicle ◽  
Mei-Yin Chan ◽  
Charlotte Hawkings ◽  
Karen Mason ◽  
Kathryn Smethurst ◽  
...  

Measurements taken from the nose are among the most important physical variables which discriminate statistically between male and female faces, yet several investigators have claimed that it is difficult to judge sex on the basis of noses presented in isolation. Previous work on the isolated nose has, however, involved the use of frontal views only, which may have obscured important physical differences between the noses of males and females. An investigation of the accuracy of judgments of the sex of isolated noses observed in frontal, profile, and three-quarter views by male and female subjects is reported. Judgment of sex was performed significantly more accurately than chance in all cases except for frontal views of female noses, where judgment was significantly less accurate than chance. Analysis of variance demonstrated a significant interaction of sex of nose and view of nose, such that male noses were identified better in frontal and in profile views, but female noses better in the three-quarter view. It is suggested that one possible reason for the seemingly contradictory role of the nose in previous studies of sex judgment is that all noses look more male in frontal views. For a nose to be perceived as female, its distinctive shape must be made available to the perceiver; this is most likely from the three-quarter view.



2000 ◽  
Vol 78 (2) ◽  
pp. 167-173 ◽  
Author(s):  
O Guillaume

Non-sexually active males and females of the cave-dwelling salamander Proteus anguinus always aggregate in the same shelters, either under stones or in fissures. However, it was not known if this behaviour results from chemical communication and (or) behavioural interactions among conspecifics. I tested the hypothesis that this is the case by using two-choice tests. The results showed that salamanders re-located their own shelter even when it was displaced. However, they preferred a shelter that belonged to a conspecific or contained faecal pellets of a conspecific to their own or a control "blank" shelter. When two salamanders were simultaneously given the choice between two blank shelters, they cohabited. When they were simultaneously given the choice between their own shelter and each other's, they used them indiscriminately and frequently cohabited. These data provide evidence that P. anguinus use chemical signals as directional cues for homing and also for social behaviour. Chemical signals may attract conspecifics, which subsequently may exhibit gregarious behaviour by occupying common shelters.



2019 ◽  
Vol 71 (2) ◽  
pp. 329-337
Author(s):  
Christian Lenzi ◽  
Chiara Grasso ◽  
Mircea Nicoara ◽  
Alexandra Savuca ◽  
Alin Ciobica ◽  
...  

Zebrafish has a complex social behavior and little is known about the role of sexual preference and their environmental social interactions. In this study we investigated the potential influence of environmental colors and shoaling preferences of zebrafish male and female populations, with a focus on visual communication. Males and females were kept for 7 days in gender-isolated tanks, with a specific habitat color for each group: green for males and red for females. After the pre-test period, all the animals were kept separated and 8 noninvasive behavioral tests were conducted in a T-maze, with the application of different visual stimuli. We did not observe any clear influence of environmental coloring on social zebrafish choices. Significant sex-related differences were found in shoaling partner preference (i.e. same sex vs. other sex, one fish vs. three fish) as follows: females showed a tendency to avoid other females and spent more time with males. Male fish did not display a preference between one or three fish stimuli and they shoaled more with another male and less with a potential sexual partner. There was an obvious difference between males and females in responses and selection of shoaling partners.



1973 ◽  
Vol 30 (7) ◽  
pp. 995-997 ◽  
Author(s):  
C. Newcombe ◽  
G. Hartman

In a two-choice maze ripe rainbow trout (Salmo gairdneri) of both sexes showed positive responses to chemical (probably olfactory) information. The possibility that visual or auditory stimuli influenced choice of channel in the maze was ruled out. Both males and females were strongly attracted to water taken from behind fish that were spawning and weakly attracted to the holding water of ripe fish that were not spawning. Brief speculation is offered about the role of chemical stimuli in the behavior of prespawning and spawning trout.



2013 ◽  
Vol 91 (8) ◽  
pp. 640-647 ◽  
Author(s):  
Veronika Ledvenyiova ◽  
Dezider Pancza ◽  
Jana Matejiková ◽  
Miroslav Ferko ◽  
Iveta Bernatova ◽  
...  

Sex and aging represent important factors that determine morbidity and mortality due to cardiovascular diseases in the human population. This study aimed to investigate the impact of aging on the response to ischemia–reperfusion in male and female rat hearts, and to explore a potential role of the PI3K–Akt pathway in the cardioprotective effects of ischemic preconditioning (IPC) in the myocardium of younger and older adult males and females. Langendorff-perfused nonpreconditioned and preconditioned hearts of 12- and 18-week-old male and female Wistar rats were subjected to regional ischemia and reperfusion with or without prior perfusion with the PI3K inhibitor wortmannin for the evaluation of ischemia-induced arrhythmias and the size of myocardial infarction (infarct size; IS). Aging did not modify IS in both sexes; however, it markedly increased susceptibility to arrhythmias. Although IPC effectively reduced IS in males and females of both ages, only the hearts of males and 18-week-old females benefited from its antiarrhythmic effect. In the preconditioned 12-week-old females, but not the 18-week-old females, and in males of both ages, wortmannin blunted the anti-infarct effect of IPC. In conclusion, activation of the PI3K–Akt pathway plays an important role in protection against lethal injury conferred by IPC in males irrespective of age. The IS-limiting effect of IPC appears to be PI3K–Akt-dependent only in the 12-week-old females.



Author(s):  
Jussara M do Carmo ◽  
Alexandre A da Silva ◽  
John E Hall

Abstract Background Previous studies suggest that obesity-induced hypertension in females, but not males, is due to leptin-mediated stimulation of aldosterone secretion and subsequent activation of the mineralocorticoid receptor (MR). Although angiotensin II type 1 receptor (AT1R) antagonism lowers blood pressure (BP) in male obese Zucker rats (OZR), which have defective leptin signaling, the potential role of sex differences in BP responses to RAAS blockade, including MR antagonism, in obesity is still unclear. We tested the cardiovascular effects of MR antagonism, alone or in combination with AT1R blockade in male and female OZR (n=5/sex) and lean Zucker rats (LZR, n=7/sex). Methods BP and heart rate (HR) were measured by telemetry 24-hrs/day. After a 6-day control period, spironolactone (40 mg/kg/day) was given for 10 days followed by a 7-day combined treatment with losartan (20 mg/kg/day), and followed by 6-day post-treatment recovery period. Results Compared to lean rats, OZR were hypertensive (Mean arterial pressure: 115±4 vs. 104±2 and 111±s vs. 100±3 mmHg for males and females) and had lower HR (355±9 vs. 393±7 and 367±10 vs. 412±13 bpm). MR blockade alone did not alter BP or HR in lean or obese male and female Zucker rats, whereas combined treatment reduced BP in obese and lean rats by 31±3 vs. 21±1 and 8±1 vs. 5±1 mmHg in males and females, respectively. No changes were observed in HR. Conclusions These results suggest that there are important sex differences in BP responses to chronic AT1R blockade but no major involvement of MR activation in BP regulation in OZR.



Author(s):  
Susana Nunes Silva ◽  
Bruno Costa Gomes ◽  
Saudade André ◽  
Ana Félix ◽  
António Sebastião Rodrigues ◽  
...  

Abstract Background Breast cancer (BC) is the most common cancer in women. In contrast, male BC is about 100 times less common than in women, being considered a rare disease. Male BC may be a distinctive subtype of BC and available data seems to indicate that male BC has a higher dependence on genetic variants than female BC. Nevertheless, the same prognostic and predictive markers are used to determine optimal management strategies for both male and female BC. Several studies have assessed the role of genetic polymorphisms (SNPs) in DNA repair genes in female BC susceptibility. However, data on male BC is scarce. Thus, the current study aimed to assess the role of SNPs in XRCC1, MUTYH and TP53 genes in a male cohort of BC, and, in addition, compare the male data with matched results previously genotyped in female BC patients. Methods The male BC cohort was genotyped through Real-Time PCR using TaqMan Assays for several SNPs previously analysed in Portuguese female BC patients. Results The results obtained indicate significant differences in BC susceptibility between males and females for the XRCC1 rs1799782, MUTYH rs3219489 and TP53 rs1042522 and rs8064946 variants. Conclusions In males, XRCC1 and TP53 variants, when in heterozygosity, seem to be related with lower susceptibility for BC, contrasting with higher susceptibility for a MUTYH variant in females. These findings may help to explain the difference in incidence of BC between the two sexes.



2018 ◽  
Vol 34 (4) ◽  
pp. 231-235
Author(s):  
Konstantina Avdikou ◽  
Charalampos Stefanatos ◽  
Marianna Tsatali ◽  
Mairy Gouva ◽  
Magda Tsolaki

The aim of this study was to investigate the differences between male and female caregivers for patients with dementia in the way they experience various psychosocial parameters such as shame, hostility, and aggression. The sample included 55 caregivers of patients with moderate and severe dementia, whereas the average age was 51 years. Female caregivers were found to experience significantly higher levels of external shame, measured by Other As Shamer scale, than male caregivers, t (53) = 2.54, P < .01. A significant difference was also found between the female and male caregivers regarding their recorded levels of internal shame, measured by Experience of Shame Scale, with female caregivers experiencing more internal shame than their male counterparts, t (53) = 2.11, P < .01. However, no significant differences were found in hostility and aggression between males and females. These results demonstrate the existence of gender differences in the levels of shame experienced by care providers for patients with dementia.



2019 ◽  
Author(s):  
Katherine J. Sellers ◽  
Matthew C.S. Denley ◽  
Atsushi Saito ◽  
Atsushi Kamiya ◽  
Deepak P. Srivastava

AbstractEstrogens play an important role in the sexual dimorphisms that occur during brain development, including the neural circuitry that underlies sex-typical and socio-aggressive behaviors. Aromatase, the enzyme responsible for the conversion of androgens to estrogens, is expressed at high levels during early development in both male and female cortices, suggesting a role for brain-synthesized estrogens during corticogenesis. This study investigated how the local synthesis of estrogens affects neurodevelopment of the cerebral cortex, and how this differs in males and females by knockdown expression of the Cyp19a1 gene, which encodes aromatase, between embryonic day 14.5 and postnatal day 0 (P0). The effects of Cyp19a1 knockdown on neural migration was then assessed. Aromatase was expressed in the developing cortex of both sexes, but at significantly higher levels in male than female mice. Under basal conditions, no obvious differences in cortical migration between male and female mice were observed. However, knockdown of Cyp19a1 increased the number GFP-positive cells in the cortical plate, with a concurrent decrease in the subventricular zone/ventricular zone in P0 male mice. The opposite effect was observed in females, with a significantly reduced number of GFP-positive cells migrating to the cortical plate. These findings have important implications for our understanding of the role of fetal steroids for neuronal migration during cerebral cortex development. Moreover, these data indicate that brain-synthesized estrogens regulate radial migration through distinct mechanisms in males and females.



PeerJ ◽  
2017 ◽  
Vol 5 ◽  
pp. e4036 ◽  
Author(s):  
Javier Manjarrez ◽  
Martha Pacheco-Tinoco ◽  
Crystian S. Venegas-Barrera

The Mexican Garter Snake (Thamnophis eques)is a terrestrial-aquatic generalist that feeds on both aquatic and terrestrial prey. We describe size-related variation and sexual variation in the diet ofT. equesthrough analysis of 262 samples of identifiable stomach contents in snakes from 23 locations on the Mexican Plateau. The snakeT. equeswe studied consumed mostly fish, followed in lesser amounts by leeches, earthworms, frogs, and tadpoles. Correspondence analysis suggested that the frequency of consumption of various prey items differed between the categories of age but not between sex of snakes, and the general pattern was a reduction of prey item diversity with size of snake. Snake length was correlated positively with mass of ingested prey. Large snakes consumed large prey and continued to consume smaller prey. In general, no differences were found between the prey taxa of male and female snakes, although males ate two times more tadpoles than females. Males and females did not differ in the mass of leeches, earthworms, fishes, frogs and tadpoles that they ate, and males and females that ate each prey taxon were similar in length. We discuss proximate and functional determinants of diet and suggest that the observed intraspecific variation inT. equescould be explored by temporal variation in prey availability, proportions of snake size classes and possible sexual dimorphism in head traits and prey dimensions to assess the role of intersexual resource competition.



Sign in / Sign up

Export Citation Format

Share Document