Search results for "Sexual Dimorphism"
showing 10 items of 154 documents
Sexually dimorphic tegumental gland openings in Laniatores (Arachnida, Opiliones), with new data on 23 species
2009
International audience; Sexually dimorphic glands often release sexual pheromones both in vertebrates and invertebrates. Species of Laniatores (Arachnida, Opiliones) seem to depend on chemical communication but few studies have addressed this topic. In this study, we review the literature for the Phalangida and present new data for 23 species of Laniatores. In 16 taxa, we found previously undescribed sexually dimorphic glandular openings on the femur, patella, metatarsus, and tarsus of legs I and metatarsus of legs III and IV. For the other species, we provide scanning electron micrographs of previously undescribed sexually dimorphic setae and pegs located on swollen regions of the legs. We…
Differential expression and costs between maternally and paternally derived immune priming for offspring in an insect
2011
1. When parasitized, both vertebrates and invertebrates can enhance the immune defence of their offspring, although this transfer of immunity is achieved by different mechanisms. In some insects, immune-challenged males can also initiate trans-generational immune priming (TGIP), but its expressions appear qualitatively different from the one induced by females similarly challenged. 2. The existence of male TGIP challenges the traditional view of the parental investment theory, which predicts that females should invest more into their progeny than males. However, sexual dimorphism in life-history strategies and the potential costs associated with TGIP may nevertheless lead to dissymmetric in…
Sexing birds using discriminant function analysis: a critical appraisal.
2011
9 pages; International audience; Discriminant function analysis (DFA) based on morphological measurements is a quick, inexpensive, and efficient method for sex determination in field studies on cryptically monomorphic bird species. However, behind the apparent standardization and relative simplicity of DFA lie subtle differences and pitfalls that have been neglected in some studies. Most of these concerns directly affect assessment of the discriminant performance, a parameter of crucial importance in practice because it provides a measure of the quality of an equation that may be used in later field studies. Using results from 141 published studies and simulations based on a large data set …
Acoustic communication in the Kittiwake Rissa tridactyla: potential cues for sexual and individual signatures in long calls
2007
International audience; Sex and individual recognition systems vary among species and can have various functions in different contexts. In order to determine the basis of identification by voice in the Kittiwake (Rissa tridactyla), the greeting calls of 32 individuals (18 males and 14 females) were recorded in May–June 2004 on the Kittiwake colony of Hornøya island (Barents sea) and analysed. On the basis of coefficient of variation calculations and discriminant analyses, we show (1) that calls are sexually dimorphic and that the dimorphism is mainly based on the value of the fundamental frequency, and (2) that calls are individually distinct, individuality being due to a complex of tempora…
Women's socioeconomic position in ontogeny is associated with improved immune function and lower stress, but not with height
2020
AbstractImmune function, height and resource accumulation comprise important life history traits in humans. Resource availability models arising from life history theory suggest that socioeconomic conditions influence immune function, growth and health status. In this study, we tested whether there are associations between family income during ontogeny, adult height, cortisol level and immune response in women. A hepatitis B vaccine was administered to 66 young Latvian women from different socioeconomic backgrounds, and blood samples were then collected to measure the level of antibodies that the women produced in response to the vaccination. Cortisol levels were measured from plasma sample…
The torso integration hypothesis revisited in Homo sapiens: Contributions to the understanding of hominin body shape evolution.
2018
Objectives: Lower thoracic widths and curvatures track upper pelvic widths and iliac blades curvatures in hominins and other primates (torso integration hypothesis). However, recent studies suggest that sexual dimorphism could challenge this assumption in Homo sapiens. We test the torso integration hypothesis in two modern human populations, both considering and excluding the effect of sexual dimorphism. We further assess covariation patterns between different thoracic and pelvic levels, and we explore the allometric effects on torso shape variation. Material and Methods: A sex-balanced sample of 50 anatomically connected torsos (25 Mediterraneans, 25 Sub-Saharan Africans) was segmented fro…
The maternal hormone in the male brain: Sexually dimorphic distribution of prolactin signalling in the mouse brain.
2018
Research of the central actions of prolactin is highly focused on females, but this hormone has also documented roles in male physiology and behaviour. Here, we provide the first description of the pattern of prolactin-derived signalling in the male mouse brain, employing the immunostaining of phosphorylated signal transducer and activator of transcription 5 (pSTAT5) after exogenous prolactin administration. Next, we explore possible sexually dimorphic differences by comparing pSTAT5 immunoreactivity in prolactin-supplemented males and females. We also assess the role of testosterone in the regulation of central prolactin signalling in males by comparing intact with castrated prolactin-supp…
Approaching Sex Differences in Cardiovascular Non-Coding RNA Research
2020
International audience; Cardiovascular disease (CVD) is the biggest cause of sickness and mortality worldwide in both males and females. Clinical statistics demonstrate clear sex differences in risk, prevalence, mortality rates, and response to treatment for different entities of CVD. The reason for this remains poorly understood. Non-coding RNAs (ncRNAs) are emerging as key mediators and biomarkers of CVD. Similarly, current knowledge on differential regulation, expression, and pathology-associated function of ncRNAs between sexes is minimal. Here, we provide a state-of-the-art overview of what is known on sex differences in ncRNA research in CVD as well as discussing the contributing biol…
Acute effects of fluoxetine on inhibitory avoidance consolidation in male and female OF1 mice
2001
The effects of acute administration of fluoxetine on memory consolidation using an inhibitory avoidance task were investigated in male and female OF1 mice. Several doses of this antidepressant (5, 10, and 20 mg/kg) were intraperitoneally administered immediately after the training session. The test session was carried out four days later and response latencies were measured in both sessions. The results showed that the highest dose of fluoxetine significantly increased response latencies of inhibitory avoidance compared with the lowest dose and the control group. Sex differences in this task were observed, females showing a better performance. But the drug's effects were not sexually dimorp…
The Metabolic Profile in Active Acromegaly is Gender-Specific.
2012
CONTEXT: The sexual dimorphism of the somatotroph axis has been documented, but whether the acromegaly-related metabolic alterations are gender-dependent has never been investigated. OBJECTIVE: The aim of the study was to evaluate the impact of gender on the metabolic parameters in acromegaly. DESIGN: We conducted a retrospective, comparative, multicenter study. PATIENTS: The 307 newly diagnosed acromegalic patients included in the study were grouped by gender: 157 men (aged 48.01 ± 14.28 yr), and 150 women (aged 48.67 ± 14.95 yr; of which 77 were premenopausal and 73 postmenopausal). OUTCOME MEASUREMENTS: We measured each component of the metabolic syndrome (MS), hemoglobin A1c, the areas …