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Sex-related Differences (sex-related + difference)
Selected AbstractsThrips see red , flower colour and the host relationships of a polyphagous anthophilic thripsECOLOGICAL ENTOMOLOGY, Issue 5 2007A. YAKU Abstract 1.,The common blossom thrips, Frankliniella schultzei, is a polyphagous anthophilic species that colonises a wide range of host-plant species across different plant taxa. The environmental cues used by these polyphagous insects to recognise and locate host plants are not known. We therefore determined if colour is an important environmental signal used by F. schultzei to recognise flowers of eight of its more significant host-plant species. 2.,The effect of flower colour on the colonisation of different host plant species by F. schultzei was investigated by collecting and analysing the following: (a) numbers of thrips from different heights and aspects of the primary host plant Malvaviscus arboreus, (b) thrips distribution within flowers of Hibiscus rosasinensis, (c) colour reflectance from flowers of eight different host-plant species, and (d) reflectance from different coloured sticky traps and the number of thrips trapped on them at different times of the day and on different dates. 3.,The results indicate that: (a) the thrips (both sexes) concentrate towards the top of the primary host plant M. arboreus and are not distributed differentially according to sunny or shady aspect of the plant, (b) the number of female thrips on H. rosasinensis was higher in anthers compared to petals (corolla) and the basal parts of the flower, and males were as numerous on the petals as were females, and (c) there is a common floral reflectance pattern (but with different intensities) across the eight host plant species, mainly in the red part of the spectrum (600,700 nm). 4.,Results of colour sticky trapping show that red attracts more female thrips compared to any other colour and that most were caught between 09.00 and 11.00 hours. By contrast, more male thrips were trapped between 07.00 and 09.00 hours. Males were more evenly distributed across the different colours but the highest numbers were associated with the yellow traps. 5.,The higher densities of thrips at the top of their host plant may be related to the early morning (07.00,11.00 hours) activity of the thrips, when the top portions of the plant are more exposed to sunlight. The sex-related distributions of F. schultzei thrips across time, coloured sticky traps, and various parts of the flowers seem to be related to mating swarm formation by the males, on the one hand, and the relative frequency and intensity of the use of M. arboreus by the females, on the other, as a feeding and oviposition site. Frankliniella schultzei females respond more strongly to red than to any other colours, so it is predicted that the spectral properties of colour recognition by this species will correlate with the predominant red reflectance of its primary host, M. arboreus, and that there may well be a sex-related difference in colour recognition within this species. [source] Juvenile Hormone Binding Protein Titers During Adult Metamorphosis in Manduca sextaENTOMOLOGICAL RESEARCH, Issue 4 2003Young Jin KANG ABSTRACT ABSTRACT During the pupal and adult stages, the JHBP levels displayed a sex-related difference, with females showing higher levels than males. A sharp increase in JHBP levels was observed at day 2 of the pupal stage. After day 2 the JHBP titer declined precipitously, and then remained unchanged until day 12 in males. JHBP titers in females decreased slightly after day 2 and then remained relatively constant until day 12. In both sexes, the JHBP levels showed a steep increase and peaked around day 15. During the previtellogenic period, the JHBP titers declined dramatically until adult ecdysis. During early adult stage, JHBP titiers in the female remained constant at preecdysis level. This information could broaden our understanding of pest physiology during adult metamorphosis, and could have extensive implications for developing insect growth regulators to control agricultural pests. [source] The Influence of Gender and Sex Steroids on Craniofacial NociceptionHEADACHE, Issue 2 2007Brian E. Cairns PhD Several pain conditions localized to the craniofacial region show a remarkable sex-related difference in their prevalence. These conditions include temporomandibular disorders and burning mouth syndrome as well as tension-type, migraine, and cluster headaches. The mechanisms that underlie sex-related differences in the prevalence of these craniofacial pain conditions remain obscure and likely involve both physiological and psychosocial factors. In terms of physiological factors relevant to the development of headache, direct evidence of sex-related differences in the properties of dural afferent fibers or durally activated second-order trigeminal sensory neurons has yet to be provided. There is, however, evidence for sex-related differences in the response properties of afferent fibers and second-order trigeminal sensory neurons that convey nociceptive input from other craniofacial tissues associated with sex-related differences in chronic pain conditions, such as those that innervate the masseter muscle and temporomandibular joint. Further, modulation of craniofacial nociceptive input by opioidergic receptor mechanisms appears to be dependent on biological sex. Research into mechanisms that may contribute to sex-related differences in trigeminal nociceptive processing has primarily focused on effect of the female sex hormone estrogen, which appears to alter the excitability of trigeminal afferent fibers and sensory neurons to noxious stimulation of craniofacial tissues. This article discusses current knowledge of potential physiological mechanisms that could contribute to sex-related differences in certain craniofacial pain conditions. [source] Relationship between breathing and cardiovascular function at rest: sex-related differencesACTA PHYSIOLOGICA, Issue 2 2010B. G. Wallin Abstract Aim:, To compare relationships at rest between breathing rate, levels of muscle sympathetic nerve activity, total peripheral resistance and cardiac output among young men and women. Methods:, Recordings were made of respiratory movements, sympathetic nerve activity (peroneal microneurography), intra-arterial blood pressure, electrocardiogram, cardiac output (open-circuit acetylene uptake technique) in 19 healthy men (age 27 ± 2 years, mean ± SEM) and 17 healthy women (age 25 ± 1 years). Total peripheral resistance and stroke volume were calculated. Four minutes epochs of data were analysed. Results:, Breathing rates and sympathetic activity were similar in men and women but compared to men, women had significantly lower blood pressures, cardiac output and stroke volume. In men breathing rate correlated positively with sympathetic activity (r = 0.58, P < 0.05) but not in women (r = 0.12, P > 0.05). Furthermore, in men, respiratory rate correlated positively with total peripheral resistance (r = 0.65, P < 0.05) and inversely with cardiac output (r = ,0.84, P < 0.05) and heart rate (r = ,0.60, P < 0.05) but there were no such relationships in women (P > 0.05 for all). Conclusions:, The positive relationship between breathing and sympathetic activity in men, and the inverse coupling of breathing to cardiac output and heart rate suggest that influences of respiration may be important not only for dynamic but also for ,tonic' cardiovascular function. The lack of relationships among these variables in women shows that there are fundamental differences in basic blood pressure regulation between the sexes. [source] Sublethal effects of methylmercury on fecal metabolites of testosterone, estradiol, and corticosterone in captive juvenile white ibises (Eudocimus albus),ENVIRONMENTAL TOXICOLOGY & CHEMISTRY, Issue 5 2009Evan M. Adams Abstract Methylmercury (MeHg) is a globally distributed neurotoxin, endocrine disruptor, and teratogen, and its effects on birds are poorly understood, especially within an environmentally relevant exposure range. In an effort to understand the potential causal relationship between MeHg exposure and endocrine development, we established four dietary exposure groups (0 [control], 0.05, 0.1, and 0.3 mg/kg wet wt/d of MeHg) of postfledging white ibises (Eudocimus albus) in a divided, free-flight aviary that spanned the estimated range of environmental exposure for this species. Fecal samples were collected from individually identified ibises over six months in 2005 and processed for hormone evaluation. Significant sex-related differences in fecal estradiol concentrations, though unpredicted in direction, suggest that this steroid could be related to juvenile development in this species. Using repeated-measures general linear models, we tested a set of candidate models to explain variation in endocrine expression. We found that MeHg exposure led to significant differences in fecal estradiol concentrations between the control and medium-dose groups, whereas differences in fecal corticosterone concentrations were observed between the control and both the low- and high-dose groups. These results suggest highly nonlinear dose-response patterns for MeHg. Many endocrine-disrupting contaminants are theorized to affect multiple endpoints in a nonlinear manner, making results difficult to interpret using a traditional toxicological approach. The evidence presented here suggests that endocrine effects of MeHg exposure could behave similarly. [source] Reduced nicotinamide adenine dinucleotide phosphate and the higher incidence of pollution-induced liver cancer in female flounderENVIRONMENTAL TOXICOLOGY & CHEMISTRY, Issue 11 2003Angela Koehler Abstract In biological effect monitoring programs, induction of biotransformation and detoxification enzymes is used as a biomarker for pollution. Yet sex differences are usually neglected in the availability of reduction equivalents needed in these metabolic pathways and may affect biomarker responses. For example, female flounder have a threefold higher incidence of macroscopic liver nodules than males of the same age class in polluted environments of the North Sea that progress toward carcinomas, whereas tumors in males virtually never develop into cancer. Evidence is presented in this review that NADPH plays a significant role in this sex-related response to xenobiotics in liver of flounder. The NADPH is needed for biosynthesis, particularly of lipids and lipoproteins, and detoxification processes such as one-electron and two-electron biotransformation and conjugation and, therefore, its availability as substrate determines biomarker responses. Biotransformation of xenobiotics is more strongly induced and conjugation processes are less affected in male flounder liver during exposure. In female liver, NADPH is required for production of the yolk precursor protein vitellogenin for oocyte production. The latter process has a higher priority than the NADPH-requiring detoxification processes because reproductive success is more relevant in evolutionary perspectives than the survival of the individual female. The data reviewed here suggest that these sex-related differences in NADPH metabolism are a major cause of the higher incidence of liver cancer in female flounder in polluted environments. [source] The Influence of Gender and Sex Steroids on Craniofacial NociceptionHEADACHE, Issue 2 2007Brian E. Cairns PhD Several pain conditions localized to the craniofacial region show a remarkable sex-related difference in their prevalence. These conditions include temporomandibular disorders and burning mouth syndrome as well as tension-type, migraine, and cluster headaches. The mechanisms that underlie sex-related differences in the prevalence of these craniofacial pain conditions remain obscure and likely involve both physiological and psychosocial factors. In terms of physiological factors relevant to the development of headache, direct evidence of sex-related differences in the properties of dural afferent fibers or durally activated second-order trigeminal sensory neurons has yet to be provided. There is, however, evidence for sex-related differences in the response properties of afferent fibers and second-order trigeminal sensory neurons that convey nociceptive input from other craniofacial tissues associated with sex-related differences in chronic pain conditions, such as those that innervate the masseter muscle and temporomandibular joint. Further, modulation of craniofacial nociceptive input by opioidergic receptor mechanisms appears to be dependent on biological sex. Research into mechanisms that may contribute to sex-related differences in trigeminal nociceptive processing has primarily focused on effect of the female sex hormone estrogen, which appears to alter the excitability of trigeminal afferent fibers and sensory neurons to noxious stimulation of craniofacial tissues. This article discusses current knowledge of potential physiological mechanisms that could contribute to sex-related differences in certain craniofacial pain conditions. [source] Gender-related differences in neonatal imitationINFANT AND CHILD DEVELOPMENT, Issue 3 2007Emese Nagy Abstract Socio-emotional behaviour is in part sex-related in humans, although the contribution of the biological and socio-cultural factors is not yet known. This study explores sex-related differences during the earliest communicative exchange, the neonatal imitation in 43 newborn infants (3,96 hours old) using an index finger extension imitative gesture. Results showed that although the experimenter presented comparable stimuli to both sexes, and the total number of movements was similar in boys and girls, girls showed more fine motor movements, a higher number of specific imitative gestures, responded faster during the imitation and showed a higher baseline heart rate during the experiment. Newborn girls, with their faster and more accurate imitative abilities, may create a more responsive and interactive social environment, which in turn may lead to differences in socio-emotional and cognitive development between girls and boys. Copyright © 2007 John Wiley & Sons, Ltd. [source] Effect of Osteoblast-Targeted Expression of Bcl-2 in Bone: Differential Response in Male and Female Mice,JOURNAL OF BONE AND MINERAL RESEARCH, Issue 8 2005Alexander G Pantschenko Abstract Transgenic mice (Col2.3Bcl-2) with osteoblast-targeted human Bcl-2 expression were established. Phenotypically, these mice were smaller than their wildtype littermates and showed differential effects of the transgene on bone parameters and osteoblast activity dependent on sex. The net effect was an abrogation of sex differences normally observed in wildtype mice and an inhibition of bone loss with age. Ex vivo osteoblast cultures showed that the transgene had no effect on osteoblast proliferation, but decreased bone formation. Estrogen was shown to stimulate endogenous Bcl-2 message levels. These studies suggest a link between Bcl-2 and sex regulation of bone development and age-related bone loss. Introduction: Whereas Bcl-2 has been shown to be an important regulator of apoptosis in development, differentiation, and disease, its role in bone homeostasis and development is not well understood. We have previously showed that the induction of glucocorticoid-induced apoptosis occurred through a dose-dependent decrease in Bcl-2. Estrogen prevented glucocorticoid-induced osteoblast apoptosis in vivo and in vitro by preventing the decrease in Bcl-2 in osteoblasts. Therefore, Bcl-2 may be an important regulator of bone growth through mechanisms that control osteoblast longevity and function. Materials and Methods: Col2.3Bcl-2 mice were developed carrying a 2.3-kb region of the type I collagen promoter driving 1.8 kb of human Bcl-2 (hBcl-2). Tissue specific expression of hBcl-2 in immunoassays validated the transgenic animal model. Histomorphometry and DXA were performed. Proliferation, mineralization, and glucocorticoid-induced apoptosis were examined in ex vivo cultures of osteoblasts. The effect of estrogen on mouse Bcl-2 in ex vivo osteoblast cultures was assayed by RT-PCR and Q-PCR. Results and Conclusions: Two Col2.3Bcl-2 (tg/+) founder lines were established and appeared normal except that they were smaller than their nontransgenic wildtype (+/+) littermates at 1, 2, and 6 months of age, with the greatest differences at 2 months. Immunohistochemistry showed hBcl-2 in osteoblasts at the growth plate and cortical surfaces. Nontransgenic littermates were negative. Western blots revealed hBcl-2 only in type I collagen-expressing tissues. Histomorphometry of 2-month-old mice showed a significant decrease in tg/+ calvaria width with no significant differences in femoral trabecular area or cortical width compared with +/+. However, tg/+ males had significantly more trabecular bone than tg/+ females. Female +/+ mice showed increased bone turnover with elevated osteoblast and osteoclast parameters compared with +/+ males. Col2.3Bcl-2 mice did not show such significant differences between sexes. Male tg/+ mice had a 76.5 ± 1.5% increase in ObS/BS with no significant differences in bone formation rate (BFR) or mineral apposition rate (MAR) compared with male +/+ mice. Transgenic females had a significant 48.4 ± 0.1% and 20.1 ± 5.8% decrease in BFR and MAR, respectively, compared with +/+ females. Osteoclast and osteocyte parameters were unchanged. By 6 months, femurs from female and male +/+ mice had lost a significant amount of their percent of trabecular bone compared with 2-month-old mice. There was little to no change in femoral bone in the tg/+ mice with age. Ex vivo cultures of osteoblasts from +/+ and Col2.3Bcl-2 mice showed a decrease in mineralization, no effect on proliferation, and an inhibition of glucocorticoid-induced apoptosis in Col2.3Bcl-2 cultures. Estrogen was shown to increase mouse Bcl-2 transcript levels in osteoblast cultures of wildtype mice, supporting a role for Bcl-2 in the sex-related differences in bone phenotype regulated by estrogen. Therefore, Bcl-2 differentially affected bone phenotype in male and female transgenic mice, altered bone cell activity associated with sex-related differences, and decreased bone formation, suggesting that apoptosis is necessary for mineralization. In addition, Bcl-2 targeted to mature osteoblasts seemed to delay bone development, producing a smaller transgenic mouse compared with wildtype littermates. These studies suggest that expression of Bcl-2 in osteoblasts is important in regulating bone mass in development and in the normal aging process of bone. [source] Dimorphic growth patterns and sex-specific reaction norms in the butterfly Lycaena hippothoe sumadiensisJOURNAL OF EVOLUTIONARY BIOLOGY, Issue 2 2001K. Fischer Directly developing larvae of the butterfly Lycaena hippothoe sumadiensis exhibited two growth strategies with one cohort passing four larval instars at high growth rates, and the other five instars at lower growth rates. The 4-instar-cohort displayed decreased development times, in combination with slightly reduced pupal and adult weights. In addition to adjustment of growth rate, omitting a larval instar may comprise a further mechanism to decrease development time when needed. Using the 4-instar-cohort, sex-related differences in reaction norms were investigated over a temperature gradient. At high temperatures, protandrous males showed early emergence at a reduced size, whereas weight of females remained similar throughout. These differences suggest that large size is more important for female than for male fitness. The pattern is similar to that previously reported for alpine L. tityrus, indicating that sex-specific reaction norms might be widespread in species living under severe time constraints. [source] Relationships between tail-flicking, morphology, and body condition in MoorhensJOURNAL OF FIELD ORNITHOLOGY, Issue 1 2006Fernando Alvarez ABSTRACT Prey-predator communication of alertness has been reported for Moorhens (Gallinula chloropus) and other species of birds. Because ability to flee is probably related to body condition, healthy potential prey may behave more conspicuously to send predators an unambiguous message. Moorhens have a contrasting rump patch that is flashed by rapid tail-flicking. During two winter months, we observed sex-related differences in the rate of tail-flicking. Females tail-flicked at a faster rate than males, and more vigilant and more symmetrical males tail-flicked faster. The rate of tail-flicking was negatively correlated to the heterophil/lymphocyte ratio in both sexes and positively correlated to hematocrit and albumin/globulin ratio in females. These results suggest that male and female Moorhens in better physical condition tail-flick at a faster rate and support the pursuit deterrent hypothesis, with healthy individuals appearing to inform predators that they would be difficult to capture. SINOPSIS Es conocida la comunicación del estado de alerta de las presas hacia los predadores potenciales en la Gallineta Gallinula chloropus y en otras especies de aves. Puesto que la facilidad de captura está probablemente relacionada con la condición física, sería de esperar que los individuos presa en mejor condición física actuaran de forma más conspicua, pudiendo así informar sin ambigüedad a los predadores. La Gallineta presenta un escudo anal contrastado, que se hace más conspicuo mediante rápidos movimientos verticales de la cola. Durante dos meses invernales se registraron las diferencias en la tasa de movimiento de cola con relación al sexo de los sujetos, así como su relación con la tasa de vigilancia y con varios parámetros de condición física. Las hembras presentaron mayor tasa de exhibición del escudo anal que los machos, y los más vigilantes y más simétricos de éstos realizaron una exhibición más rápida. Mientras que en ambos sexos la tasa de exhibición apareció relacionada negativamente con la razón heterófilos/linfocitos, en las hembras se mostró positivamente relacionada con su hematocrito y con la razón albúmina/globulina. Estos resultados sugieren que los machos y hembras con mejor salud, así como los machos con tarsos más simétricos, realizan una más rápida exhibición, lo que apoya la hipótesis del efecto disuasorio a la persecución, ya que las presas potenciales podrían estar informando a los predadores respecto a la dificultad de su captura. [source] Transfer of life-history phenology from mothers to progeny in a solitary univoltine parasitoidPHYSIOLOGICAL ENTOMOLOGY, Issue 2 2010ANDREW A. FORBES Among univoltine insects that experience diapause, differences in emergence timing between adult males and females are expected to be dictated by sex-specific developmental factors. In multivoltine insects without a diapause, there is often an additional relationship between the date of oviposition and the date of adult emergence. Differences between male and female emergence timing in the latter case can therefore be influenced by female sex-allocation decisions. In the present study, it is shown that eggs of a univoltine parasitoid wasp Diachasma alloeum Muesebeck (Hymenoptera: Braconidae) that are laid earlier also eclose earlier during the subsequent year, independent of (although complementary to) sex-related differences in development time. The implications of this pattern for sex allocation decisions by female univoltine parasitoids are discussed. [source] Temporal pattern of feeding activity in the firebug Pyrrhocoris apterus and its relation to sex, wing dimorphism and physiological state of adultsPHYSIOLOGICAL ENTOMOLOGY, Issue 1 2007RADOMÍR SOCHA Abstract The present study tested whether the pattern of feeding activity in the firebug Pyrrhocoris apterus (L.) is sex- and wing morph-related, diurnal or nocturnal, as well as whether the feeding rhythm persists in constant darkness. Temporal patterns of feeding activity are analysed in macropterous and brachypterous adults reared under long-day (LD 18 : 6 h) and short-day (LD 12 : 12 h) photoperiods, and in adults transferred to constant darkness. In females, the total feeding activity is highest in long-day reproductively active brachypters, intermediate in short-day diapausing brachypters, and lowest in macropters; the differences among males are substantially smaller. Although the total feeding activity of macropterous males is higher than in macropterous females, no sex-related differences are found in feeding activity of diapausing and reproductively active brachypters. The frequency of feeding exhibits sex-related differences, with obviously higher values in males. Mean feeding periods of macropterous and reproductively active brachypterous males are shorter than in females of the same wing morph. Mean interfeeding periods are longest in macropters, intermediate in diapausing brachypters, and shortest in reproductively active brachypters, and always lower in males than in females. The study shows that the feeding activity of P. apterus adults is age-, sex- and wing morph-related, and exhibits a diurnal pattern, except in reproductively active brachypterous females. The latter do not express a clear diurnal rhythm of feeding, presumably because of interactions with cycles of egg development and oviposition. The persistence of diurnal rhythm of feeding activity in short-day brachypterous females transferred to constant darkness indicates an endogeneity of this rhythm in P. apterus. [source] Increased prevalence of renal disease in systemic lupus erythematosus families with affected male relativesARTHRITIS & RHEUMATISM, Issue 2 2002Catherine M. Stein Objective To distinguish familial differences from sex-related differences in the clinical manifestations of systemic lupus erythematosus (SLE). Methods A total of 372 affected individuals from 160 multiplex SLE pedigrees were analyzed. Twenty-five of these pedigrees contained at least 1 affected male relative. Comparisons of the presence of each of the 11 1982 American College of Rheumatology criteria for SLE were made between female family members with affected male relatives and those without affected male relatives, using Fisher's exact tests. Results The presence of renal disease was significantly increased in female family members with an affected male relative when compared with those with no affected male relative (68% and 43%, respectively; P = 0.002). This trend remained after stratifying by race and was most pronounced in European Americans. A familial basis for differences in hematologic and immunologic manifestations was also suggested, while arthritis and dermatologic features appeared to be most influenced by sex. Conclusios Our results demonstrate that the increased prevalence of renal disease previously reported in men with SLE is, in large part, a familial rather than sex-based difference, at least in multiplex SLE families. Distinguishing familial from sex-related differences may facilitate efforts to understand the genetic and hormonal factors that underlie this complex autoimmune disease. [source] Sex ratio and associated risk factors for 50 congenital anomaly types: Clues for causal heterogeneityBIRTH DEFECTS RESEARCH, Issue 1 2004Monica Rittler Abstract BACKGROUND Sex ratio (SR) deviations have been reported for many congenital anomalies, but so far no satisfactory explanation for these deviations has been found. The aim of this study was to detect sex-related differences in the association between risk factors and congenital anomalies, and to relate these differences with possibly underlying causes of birth defects. METHODS Between 1982 and 1999, 1,444,646 newborn infants were examined by the Estudio Colaborativo Latino Americano de Malformaciones Congénitas (ECLAMC) network of South American maternity hospitals. Male relative risks were established for 39,425 infants with 50 selected single anomalies. Associations between male sex and risk factors were identified in nonmalformed infants. In malformed infants, sex-related risk differences were established, and the SR of these infants, with and without associated risk factors, were compared. RESULTS Infants with neural tube defects (NTDs) and intrauterine growth restriction had a lower SR than those with normal growth, while spina bifida without hydrocephaly (SB[sHy]) was the only NTD subtype without a significant female predominance. Multigravidity lowered the SR of SB(sHy) and HPP (HPP) cases. Increased paternal age inverted the SR of cleft lip (CL) with or without cleft palate (CL[P]) cases from male to female. CONCLUSIONS The results indicate etiological differences between high and low SB, a stronger relationship between multigravidity and female sex of the offspring than between multigravidity and a specific congenital anomaly, and a possible involvement of dominant mutations for CL(P), as suggested by the association with increased paternal age. Birth Defects Research (Part A) 67:000,000, 2003. © 2003 Wiley-Liss, Inc. [source] | |||||||||||||