Sex-Specific Associations between Social Behavior, Its Predictability, and Fitness in a Wild Lizard.

AbstractSocial environments impose a number of constraints on individuals' behavior. These constraints have been hypothesized to generate behavioral variation among individuals, social responsiveness, and within-individual behavioral consistency (also termed "predictability"). In particular, the social niche specialization hypothesis posits that higher levels of competition associated with higher population density should increase among-individual behavioral variation and individual predictability as a way to reduce conflicts. Being predictable should hence have fitness benefits in group-living animals. However, to date empirical studies of the fitness consequences of behavioral predictability remain scarce. In this study, we investigated the associations between social behavior, its predictability, and fitness in the eastern water dragon (Intellagama lesueurii), a wild gregarious lizard. Since this species is sexually dimorphic, we examined these patterns both between sexes and among individuals. Although females were more sociable than males, there was no evidence for sex differences in among-individual variation or predictability. However, females exhibited positive associations between social behavior, its predictability, and survival, while males exhibited only a positive association between mean social behavior and fitness. These findings hence partly support predictions from the social niche specialization hypothesis and suggest that the function of social predictability may be sex dependent.

Effects of Testosterone on Gene Expression Are Concordant between Sexes but Divergent across Species of Sceloporus Lizards.

AbstractHormones mediate sexual dimorphism by regulating sex-specific patterns of gene expression, but it is unclear how much of this regulation involves sex-specific hormone levels versus sex-specific transcriptomic responses to the same hormonal signal. Moreover, transcriptomic responses to hormones can evolve, but the extent to which hormonal pleiotropy in gene regulation is conserved across closely related species is not well understood. We addressed these issues by elevating testosterone levels in juvenile females and males of three Sceloporus lizard species before sexual divergence in circulating testosterone and then characterizing transcriptomic responses in the liver. In each species, more genes were responsive to testosterone in males than in females, suggesting that early developmental processes prime sex-specific transcriptomic responses to testosterone later in life. However, overall transcriptomic responses to testosterone were concordant between sexes, with no genes exhibiting sex-by-treatment interactions. By contrast, hundreds of genes exhibited species-by-treatment interactions, particularly when comparing distantly related species with different patterns of sexual dimorphism, suggesting evolutionary lability in gene regulation by testosterone. Collectively, our results indicate that early organizational effects may lead to sex-specific differences in the magnitude, but not the direction, of transcriptomic responses to testosterone and that the hormone-genome interface accrues regulatory changes over evolutionary time.

Sex estimation from patellar measurements in a contemporary Italian population: a machine learning approach.

Biological sex estimation in forensic anthropology is a crucial topic, and the patella has shown promise in this regard due to its sexual dimorphism. This study uses 12 machine learning models for sex estimation based on three patellar measurements (maximum height, breadth, and thickness). Data was collected from 180 skeletons of a contemporary Italian population (83 males and 97 females) as well as from an independent sample of 21 forensic cases (13 males and 8 females). Statistical analyses indicated that each of the variables exhibited significant sexual dimorphism. To predict biological sex, the classifiers were built using 70% of a reference sample, then tested on the remaining 30% of the original sample and then tested again on the independent sample. The different classifiers generated accuracies varied between 0.85 and 0.91 on the reference sample and between 0.71 and 0.95 for the validation sample. SVM classifier stood out with the highest accuracy and seemed the best model for our study.This study contributes to the growing application of machine learning in forensic anthropology by being the first to apply such techniques to patellar measurements in an Italian population. It aims to enhance the accuracy and efficiency of biological sex estimation from the patella, building on promising results observed with other skeletal elements.

Impact of maternal high-fat diet on offspring gut microbiota during short-term high-fat diet exposure in mice.

Alterations in the gut microbiome have been linked to obesity, with maternal high-fat diet (HF) playing a role in shaping offspring microbiome composition. However, the sex-specific responses to maternal HF diet and the impact of subsequent dietary challenges remain unclear. This study investigated the effects of maternal HF diet on offspring gut microbiota structure and predicted functional profile in response to short-term postnatal HF diet exposure with a focus on sex-specific responses. Female and male offspring of maternal control (C) diet or maternal HF diet were weaned onto C diet or HF diet. Offspring were euthanized at 13 weeks of age and cecal contents were collected for bacterial taxonomic profiling. Maternal HF diet reduced α-diversity, notably in male offspring weaned onto HF diet. Sex-specific differences were observed in the gut microbial composition and predicted functional potential. Furthermore, the influence of maternal diet on bacterial community structure and functional potential varied depending on postnatal diet. Maternal HF diet led to increased relative abundance of Corynebacterium in female offspring and decreased abundance of Akkermansia and Roseburia in male offspring. These findings underscore the sexually dimorphic nature of maternal HF diet effects on gut microbiota composition and function, with implications for developmental programming and metabolic health.

The effect of extracellular potassium concentration on the oscillation frequency of the pacemaker nucleus in the weakly electric fish Apteronotus leptorhynchus.

The weakly electric brown ghost knifefish (Apteronotus leptorhynchus) exhibits a pronounced sexual dimorphism in its electric behavior-males discharge at higher frequencies than females, with little overlap between the sexes. The frequency of these electric organ discharges is controlled by the frequency of the synchronized oscillations of the medullary pacemaker nucleus. Previous studies have suggested that sex-specific differences in the morphology and gene expression pattern of the astrocytic syncytium that envelopes the pacemaking neural network cause differences in its capacity to buffer the extracellular concentration of K+. This change in the K+ buffering capacity affects the K+ equilibrium potential of the neurons constituting the neural network, which in turn modulates the frequency of the pacemaker nucleus. In the present study, we have tested a critical element of this hypothesis by examining whether, and how, changes in the extracellular K+ concentration influence the frequency of the pacemaker nucleus oscillations. By using an in vitro preparation of the pacemaker nucleus, the results of this investigation demonstrate that exposure of this nucleus to acutely increased/decreased concentrations of K+ in the perfusate (while maintaining osmolarity) leads to concentration-dependent increases/decreases in the frequency of the synchronized oscillations generated by the pacemaker nucleus.

Roles of Growth Hormone-Dependent JAK-STAT5 and Lyn Kinase Signaling in Determining Lifespan and Cancer Incidence.

In rodents, loss of growth hormone (GH) or its receptor is associated with extended lifespan. We aimed to determine the signaling process resulting in this longevity using GH receptor (GHR)-mutant mice with key signaling pathways deleted and correlate this with cancer incidence and expression of genes associated with longevity. GHR uses both canonical janus kinase (JAK)2-signal transducer and activator of transcription (STAT) signaling as well as signaling via the LYN-ERK1/2 pathway. We used C57BL/6 mice with loss of key receptor tyrosines and truncation resulting in 1) loss of most STAT5 response to GH; 2) total inability to generate STAT5 to GH; 3) loss of Box1 to prevent activation of JAK2 but not LYN kinase; or 4) total knockout of the receptor. For each mutant we analyzed lifespan, histopathology to determine likely cause of death, and hepatic gene and protein expression. The extended lifespan is evident in the Box1-mutant males (retains Lyn activation), which have a median lifespan of 1016 days compared to 890 days for the Ghr-/- males. In the females, GhrBox1-/- mice have a median lifespan of 970 days compared to 911 days for the knockout females. Sexually dimorphic GHR-STAT5 is repressive for longevity, since its removal results in a median lifespan of 1003 days in females compared to 734 days for wild-type females. Numerous transcripts related to insulin sensitivity, oxidative stress response, and mitochondrial function are regulated by GHR-STAT5; however, LYN-responsive genes involve DNA repair, cell cycle control, and anti-inflammatory response. There appears to be a yin-yang relationship between JAK2 and LYN that determines lifespan.

Interactions between sexual signaling and wing size drive ecology and evolution of wing colors in Odonata.

Insect coloration has evolved in response to multiple pressures, and in Odonata (dragonflies and damselflies) a body of work supports a role of wing color in a variety of visual signals and potentially in thermoregulation. Previous efforts have focused primarily on melanistic coloration even though wings are often multicolored, and there has yet to be comprehensive comparative analyses of wing color across broad geographic regions and phylogenetic groups. Percher vs. flier flight-style, a trait with thermoregulatory and signaling consequences, has not yet been studied with regard to color. We used a new color clustering approach to quantify color across a dataset of over 8,000 odonate wing images representing 343 Nearctic species. We then utilized phylogenetically informed Bayesian zero-inflated mixture models to test how color varies with mean ambient temperature, body size, sex and flight-style. We found that wing coloration clustered into two groups across all specimens - light brown-yellow and black-dark brown - with black-dark brown being a much more cohesive grouping. Male perchers have a greater proportion of black-dark brown color on their wings as do species with longer wings. In colder climates, odonates were more likely to have black-dark brown color present, but we found no relationship between the proportion of black and temperature. Light brown-yellow showed similar scaling with wing length, but no relationship with temperature. Our results suggest that black-dark brown coloration may have a limited role in thermoregulation, while light brown-yellow does not have such a role. We also find that the odonate sexes are divergent in wing color in percher species only, suggesting a strong role for color in signaling in more territorial males. Our research contributes to an understanding of complex interactions driving ecological and evolutionary dynamics of color in animals.

Sexual dimorphism and the impact of aging on ball rolling associated locomotor behavior in Drosophila.

Insects exhibit remarkable ability to interact with inanimate objects to facilitate essential behaviors such as foraging, reproduction, shelter building, and defense. In the present study, we assessed whether Drosophila interacts with inanimate objects when they were suspended on their wings and provided with a thermopolis ball (foam ball). Drosophila indeed exhibited ball rolling behaviour. We further examined the sexual dimorphism in this ball rolling associated locomotor behaviour. We carried out a ball rolling assay using 3 day old male and female w1118 flies and measured the duration for which the flies could roll the ball without dropping it within a 10 minute period. The ball was returned to the flies whenever they dropped it and we calculated the number of times the ball was dropped within the 10 minute duration. Females exhibited a longer ball holding duration than males. We also observed a decrease in ball holding duration and an increase in the number of times the ball was dropped by 15 day old male and female flies than their younger counterparts. These results suggest sexual dimorphism and age dependent alterations in Drosophila ball rolling associated locomotor behavior.

Pre-Copulatory Sexual Selection Predicts Sexual Size Dimorphism: A Meta-Analysis of Comparative Studies.

Size differences between males and females are common across the tree of life (termed sexual size dimorphism; SSD), and have fundamental implications for ecology, life history and behaviour of both sexes. Conventionally, SSD is thought to evolve in response to sex-specific sexual selection but more recent work suggests that ecological processes can also promote sex-differences in size. Here, we provide a global test for the role of sexual selection in the evolution of sexual size dimorphism using data from 77 comparative studies spanning the major classes of the animal kingdom. We show that intense sexual selection typically correlates with male-biased SSD across species. Importantly, pre-copulatory but not post-copulatory sexual selection predicts SSD, suggesting a pervasive role of premating male-male competition and female choice to drive sex differences in body size. Collectively, our findings suggest that pre-copulatory sexual selection plays a major role in the evolution of male-biased SSD.

Gene co-expression networks reveal sex-biased differences in musculoskeletal ageing.

Aging is a universal and progressive process involving the deterioration of physiological functions and the accumulation of cellular damage. Gene regulation programs influence how phenotypes respond to environmental and intrinsic changes during aging. Although several factors, including sex, are known to impact this process, the underlying mechanisms remain incompletely understood. Here, we investigate the functional organization patterns of skeletal muscle genes across different sexes and ages using gene co-expression networks (GCNs) to explore their influence on aging. We constructed GCNs for three different age groups for male and female samples, analyzed topological similarities and differences, inferred significant associated processes for each network, and constructed null models to provide statistically robust results. We found that each network is topologically and functionally distinct, with young women having the most associated processes, likely due to reproductive tasks. The functional organization and modularity of genes decline with age, starting from middle age, potentially leading to age-related deterioration. Women maintain better gene functional organization throughout life compared to men, especially in processes like macroautophagy and sarcomere organization. The study suggests that the loss of gene co-expression could be a universal aging marker. This research offers insights into how gene organization changes with age and sex, providing a complementary method to analyze aging.

Metabolic dysfunction-associated steatotic liver disease exhibits sex-specific microbial heterogeneity within intestinal compartments.

Background: Evidence suggests that the gastrointestinal microbiome plays a significant role in the biology of metabolic dysfunction-associated steatotic liver disease (MASLD). However, it remains unclear whether disparities in the gut microbiome across intestinal tissular compartments between the sexes lead to MASLD pathogenesis. Methods: Sex-specific analyses of microbiome composition in two anatomically distinct regions of the gut, the small intestine and colon, were performed using an experimental model of MASLD. The study involved male and female spontaneously hypertensive rats and the Wistar-Kyoto control rat strain, which were fed either a standard chow diet or a high-fat diet for 12 weeks to induce MASLD (12 rats per group). High-throughput 16S sequencing was used for microbiome analysis. Results: There were significant differences in the overall microbiome composition of male and female rats with MASLD, including variations in topographical gut regions. The beta diversity of the jejunal and colon microbiomes was higher in female rats than in male rats (PERMANOVA p-value=0.001). Sex-specific analysis and discriminant features using LEfSe showed considerable variation in bacterial abundance, along with distinct functional properties, in the jejunum and colon of animals with MASLD. Significantly elevated levels of lipopolysaccharide and protein expression of Toll-like receptor 4 were observed in the livers of male rats with MASLD compared with their female counterparts. Conclusion: This study uncovered sexual dimorphism in the gut microbiome of MASLD and identified microbial heterogeneity within intestinal compartments. Insights into sex-specific variations in gut microbiome composition could facilitate customised treatment strategies.

Sex prediction according to digital analysis of the morphological characteristics of maxillary posterior teeth in a Pakistani population.

Objective: Researchers have examined several dental characteristics to identify differences in tooth morphology between males and females in various populations. Nevertheless, no research has been undertaken to ascertain sexual dimorphism and develop a sex prediction model by using the groove pattern, cusp number and occlusal pattern in any population group. Therefore, this study accessed the sexual differences and the ability to predict sex according to these characteristics of maxillary teeth in the Pakistani community. Method: A total of 130 dental casts were selected (65 each from males and females). Digital images of the occlusal surface of the maxillary first premolar, second premolar and first molar were captured with a Canon Powershot A2200 14.1 MP digital camera with 4× optical zoom. Cusp number, groove pattern and occlusal pattern were recorded for each tooth type. Data were analysed with chi-square tests and logistic regression analysis. Results: The groove pattern and occlusal pattern of the maxillary first premolar and first molar showed significant sexual dimorphism (p < 0.05). The cusp number of the maxillary first molar also displayed a statistically significant difference between males and females (p < 0.05). The sex prediction accuracy was 76.7% for the training samples and 70% for the test samples. Conclusion: We observed significant sexual dimorphism in the groove pattern and the occlusal pattern of the maxillary first premolar and maxillary first molar teeth, as well as the cusp number of the maxillary first molar teeth. The prediction model demonstrated good accuracy, at 76.7%, and hence can be used for sex prediction in the Pakistani population.

Male is the default sex: functional significance of the sex determination cascade in horned dung beetles.

Sex-specific trait expression represents a striking dimension of morphological variation within and across species. The mechanisms instructing sex-specific organ development have been well studied in a small number of insect model systems, suggesting striking conservation in some parts of the somatic sex determination pathway while hinting at possible evolutionary lability in others. However, further resolution of this phenomenon necessitates additional taxon sampling, particularly in groups in which sexual dimorphisms have undergone significant elaboration and diversification. Here, we functionally investigate the somatic sex determination pathway in the gazelle dung beetle Digitonthophagus gazella, an emerging model system in the study of the development and evolution of sexual dimorphisms. We find that RNA interference (RNAi) targeting transformer1 (tra1) caused chromosomal females to develop morphological traits largely indistinguishable from those normally only observed in males, and that tra1 RNAi is sufficient to induce splicing of the normally male-specific isoform of doublesex in chromosomal females, while leaving males unaffected. Further, intersex RNAi was found to phenocopy previously described RNAi phenotypes of doublesex in female but not male beetles. These findings match predictions derived from models of the sex determination cascade as developed largely through studies in Drosophila melanogaster. In contrast, transformed2 RNAi resulted in larval mortality and was not sufficient to affect doublesex splicing, whereas RNAi targeting Sex-lethal and two putative orthologs of hermaphrodite yielded no obvious phenotypic modifications in either males or females, raising the possibility that the function of a subset of sex determination genes may be derived in Diptera and thus non-representative of their roles in other holometabolous orders. Our results help illuminate how the differential evolutionary lability of the somatic sex determination pathway has contributed to the extraordinary morphological diversification of sex-specific trait expression found in nature.

Antennal sensilla of Cyclocephala barrerai (Coleoptera: Melolonthidae): morphology, sexual dimorphism, allometric relationships, and function.

Scarab beetles use pheromones and volatiles to search for their partners and host plants. The perception of these compounds occurs in the beetle antennae, particularly in the sensilla. Relatively few studies have morphologically and physiologically characterized the sensilla of scarab beetles. Cyclocephala barrerai Martínez is a beetle distributed in Mexico. Male beetles have larger antennal lamellae than females, and in both cases, the size of this structure is related to their weight. Previous studies have reported that both sexes are attracted to bacterial volatiles isolated from the female genital chambers. Female cuticular hydrocarbons may act as a sexual contact pheromone. However, antennal sensilla and their electrophysiological responses to behaviorally relevant compounds remain to be investigated. Here, we describe and report the types, allometric relationships, and functions of sensilla found in the lamellae of both C. barrerai sexes. Sensilla were identified, classified, measured, and counted to identify intra and intersexual relationships. The single sensillum recordings showed that plant volatiles, hydrocarbons, and heat stimulated receptor neurons. We identified 2 new types of sensilla basiconica in the scape. Males have more and larger antennal sensilla placodea IV, which specializes in detecting pheromones, plant volatiles, and heat. Females have a greater diversity of sensilla.

The high-fat diet and low-dose streptozotocin type-2 diabetes model induces hyperinsulinemia and insulin resistance in male but not female C57BL/6J mice.

Translation of preclinical findings on the efficacy of dietary interventions for metabolic disease to human clinical studies is challenging due to the predominant use of male rodents in animal research. Our objective was to evaluate a combined high-fat (HF) diet and low-dose streptozotocin (STZ) model for induction of type-2 diabetes (T2D) in male and female C57BL/6J mice. We hypothesized that T2D biomarkers would differ significantly between sexes. Mice were administered either a low-fat (LF) diet (10% kcal from fat), or HF diet (60% kcal from fat) + STZ injections (30 mg/kg/d for 3 days). Both sexes gained weight and developed impaired postprandial oral glucose tolerance on the HF+STZ treatment compared to LF. Only male mice on HF + STZ developed fasting hyperglycemia, fasting hyperinsulinemia and insulin resistance, suggesting that the underlying causes of postprandial hyperglycemia differed between sexes. Principal component analysis of measures such as body weights, glucose and insulin concentrations indicated metabolic derangement for males only on HF+STZ treatment, while LF group males and both groups of females significantly overlapped. Based on our data, we accept our hypothesis that the combined high-fat diet and low-dose STZ model for T2D phenotypes differs significantly in its effect on mice based on sex. The HF diet + low-dose STZ model is not useful for studying insulin resistance in females. Other models are needed to model T2D, and study the effects of dietary interventions in this disease, in females. Sexual dimorphism remains a significant challenge for both preclinical and clinical research.

The Sexual Dimorphism in Rectum and Protein Digestion Pathway Influence Sex Pheromone Synthesis in Male Bactrocera Dorsalis.

Sexual dimorphism is a crucial aspect of mating and reproduction in many animals, yet the molecular mechanisms remain unclear. In Bactrocera dorsalis, sex pheromones trimethylpyrazine (TMP) and tetramethylpyrazine (TTMP) are specifically synthesized by Bacillus strains in the male rectum. In the female rectum, Bacillus strains are found, but TMP and TTMP are not, indicating sexually dimorphic differences in sex pheromone synthesis. Our anatomical observations and precursor measurements revealed significant differences in rectal structure and ammonium levels between sexes.  In vitro and in vivo experiments reveal that ammonium is vital for sex pheromone synthesis in rectal Bacillus strains. Comparative transcriptome analysis identified ammonium-producing genes (carboxypeptidase B and peptide transporter) in the protein digestion pathway that show much higher expression in the male rectum than in the female rectum. Knocking down the expression of either carboxypeptidase B (or inhibiting enzyme activity) or peptide transporter decreases rectal ammonium levels significantly, resulting in the failure of sex pheromone synthesis in the male rectum. This study provides insights into the presence of sexual dimorphism in internal organs and their functionalities in male-specific sex pheromone synthesis and has significant implications for understanding the molecular mechanisms underlying sex pheromone synthesis by symbionts in insects.

Reference-based genome assembly and comparative genomics of Calamus Brandisii Becc. for unveiling sex-specific genes for early gender detection.

Calamus brandisii Becc. is an endangered rattan species indigenous to the Western Ghats of India and used in the furniture and handicraft industries. However, its dioecious nature and longer flowering time pose challenges for conservation efforts. Developing markers for early gender detection in seedlings is crucial for maintaining viable populations for in-situ and ex-situ conservation. Currently, no sex chromosomes or gender-specific genes have been reported in the species. We report the first comprehensive comparative genomics study between the male and female genomes of C. brandisii to identify polymorphisms and potential genes for gender determination. Reference-based assembly was conducted and the male and female genomes were predicted to contain 43,810 and 50,493 protein-coding genes respectively. The haploid genome size was ∼691 Mb and ∼884 Mb for male and female genomes respectively. Comparative analysis revealed significant genetic variation between the two genomes including 619,776 SNPs, 73,659 InDels, 212,123 Structural variants (SVs) and 305 copy number variations (CNVs). A total of 5 male-specific and 11 female-specific genes linked to the sex determining region was predicted. The genomic variants identified between the two genomes could be used in development of markers for early gender identification in C. brandisii for restoration programs. The gender-specific genes identified in this study also provide new insights into the mechanisms of sex determination and differentiation in rattans.

Fetal body composition reference charts and sexual dimorphism using magnetic resonance imaging.

BACKGROUND: The American Academy of Pediatrics advises that the nutrition of preterm infants should target a body composition similar to that of a fetus in utero. Still, reference charts for intrauterine body composition are missing. Moreover, data on sexual differences in intrauterine body composition during pregnancy are limited. OBJECTIVES: The objective of this study was to create reference charts for intrauterine body composition from 30 to 36+6 weeks postconception and to evaluate the differences between sexes. METHODS: In this single-center retrospective study, data from 197 normal developing fetuses in late gestation was acquired at 3T magnetic resonance imaging (MRI) scans, including True Fast Imaging with Steady State Free Precession and T1-weighted 2-point Dixon sequences covering the entire fetus. Deep convolutional neural networks were utilized to automatically segment the fetal body and subcutaneous adipose tissue. The fetus's body mass (BM), fat signal fraction (FSF), fat mass (FM), FM percentage (FM%), fat-free mass (FFM), and FFM percentage (FFM%) were calculated. Using the Generalized Additive Models for Location, Scale, and Shape (GAMLSS) method, reference charts were created, and sexual dimorphism was examined using analysis of covariance (ANCOVA). A P value <0.05 was deemed significant. RESULTS: Throughout late gestation, BM, FSF, FM, FM%, and FFM increased, although the FFM% decreased. Reference charts and gestational age and sex-specific percentiles are provided. Males exhibited significantly higher BM (7.2%; 95% confidence interval [95% CI]: 1.9, 12.4), FFM (8.5%; 95% CI: 3.7, 13.4), and FFM% (1.2%; 95% CI: 0.6, 1.7) and lower FSF (-3.6%; 95% CI: -5.6 to -1.8) and FM% (-1.2%; 95% CI: -1.7 to -0.6), (P < 0.001) compared with females, with no significant difference in FM between sexes (P = 0.126). CONCLUSIONS: MRI-derived intrauterine body composition growth charts are valuable for tracking growth in preterm infants. This study demonstrated that sexual differences in body composition are already present in the intrauterine phase.

Vasopressinergic sexual dimorphism: Sex chromosome complement and organizational hormonal effects.

This study aimed to analyze the role of the sex chromosomes (SCC: XX/XY) and the interaction with organizational hormonal effects on Avp gene expression at the supraoptic (SON) and paraventricular nuclei (PVN) due to water deprivation, as well as on the vasopressinergic sexually dimorphic antidiuretic and pressor responses. For this purpose, we used gonadectomized (GDX) transgenic mice of the "four core genotypes" model, in which the effect of gonadal sex and SCC are dissociated. A significant interaction between treatment and SCC on Avp gene expression at the SON was observed. Regardless of sex, XX mice showed higher basal expression than those with XY; however after water deprivation no changes in mRNA Avp expression were observed in the XX group, while an increase for XY was reported. At the PVN an interaction of SCC, organizational hormonal, and treatment factors was observed, revealing an increase in Avp gene expression in the XY-GDX male DEP group. Although no SCC or organizational hormonal effects were observed on the demopressin-antidiuretic response and renal Avpr2 mRNA expression, an interplay of organizational hormonal and SCC factors in short and medium-term vasopressin-blood pressure regulation were reported. XX-GDX females showed a facilitated vasopressin-bradycardic baroreflex response when compared to the other genotypes. Furthermore, although vasopressin continuous infusion resulted initially in the expected increase in the percentage change in MAP in all genotypes, in XX-GDX male and female this increase was sustained until the 30-min infusion, while in XY-GDX male and in XY-GDX female mice a decrease in MAP was observed.

Diversity of attachment systems in heelwalkers (Mantophasmatodea) - highly specialized, but uniform.

BACKGROUND: Heelwalkers possess a highly modified tarsal attachment system. All extant species lift the distalmost tarsomere permanently off the substrate and primarily use their euplantulae for locomotion. The combination of a smooth adhesive pad (arolium) on the pretarsus and fibrillary attachment pads on the euplantulae offers valuable insights for translational approaches, but its infra-order diversity remains unexplored. RESULTS: We explored the morphology of the tarsal attachment apparatus of Mantophasmatodea based on a representative taxon sampling spanning a large fraction of species of this group and compared morphological differences in the specialized morphology of this system across species and sexes. Our scanning electron microscope investigation of the tarsi of 11 species (52% of all described extant species) revealed an overall very consistent ground pattern and almost no specific adaptations. There are only minor, but mostly clade-specific differences in the shape of the adhesive setae on the tarsal euplantulae and in the morphology and density of the acanthae on the pretarsal arolium. Both features differ primarily between Austrophasmatidae in comparison to the remaining Mantophasmatodea taxa. CONCLUSION: We conclude that the strong specialization of the mantophasmatodean tarsal attachment sufficiently copes with the diversity of substrates the insects are exposed to.