Paternally expressed gene 3 (Pw1/Peg3) promotes sexual dimorphism in metabolism and behavior

The paternally expressed gene 3 (Pw1/Peg3) is a mammalian-specific parentally imprinted gene expressed in stem/progenitor cells of the brain and endocrine tissues. Here, we compared phenotypic characteristics in Pw1/Peg3 deficient male and female mice. Our findings indicate that Pw1/Peg3 is a key player for the determination of sexual dimorphism in metabolism and behavior. Mice carrying a paternally inherited Pw1/Peg3 mutant allele manifested postnatal deficits in GH/IGF dependent growth before weaning, sex steroid dependent masculinization during puberty, and insulin dependent fat accumulation in adulthood. As a result, Pw1/Peg3 deficient mice develop a sex-dependent global shift of body metabolism towards accelerated adiposity, diabetic-like insulin resistance, and fatty liver. Furthermore, Pw1/Peg3 deficient males displayed reduced social dominance and competitiveness concomitant with alterations in the vasopressinergic architecture in the brain. This study demonstrates that Pw1/Peg3 provides an epigenetic context that promotes male-specific characteristics through sex steroid pathways during postnatal development.

Cardiac Radiographic Measurements in Ferrets Using the OsiriX MD Programme

Objectives: To adapt the vertebral heart scale (VHS) for use in ferrets and identify new scales and tools that allow to establish the normal heart size by means of radiography more quickly and effectively.Methods: Forty healthy pet ferrets (Mustela putorius furo) were used in this prospective study. The measurements were made on right lateral, left lateral, ventrodorsal, and dorsoventral projections, using OsiriX MD medical imaging software, to evaluate sex effect and variance within the different heart scales. Cardiac measurements were also correlated to VHS and the cardiac dimension in the same projection.Results: Most of the cardiac measurements were significantly different between males and females. The results for the VHS were: right lateral VHS (RL-VHS): 5.52 ± 0.28 v (vertebrae units); left lateral (LL-VHS): 5.55 ± 0.28 v; and dorsoventral VHS (DV-VHS): 6.22 ± 0.34 v for males and RL-VHS: 5.24 ± 0.2 v; LL-VHS: 5.25 ± 0.20 v; and DV-VHS: 5.97 ± 0.35 v for females. Regarding the sternebral heart scale (SHS), the values were: RL-SHS: 5.10 ± 0.20 s (sternebrae units) and LL-SHS: 5.11 ± 0.20 s for males and RL-SHS: 4.67 ± 0.24 s and LL-SHS: 4.67 ± 0.28 s for females. The new measurements based on determining the cardiac area were also marked by clear sexual dimorphism, as shown for the cardiac area-axis (AREA-AXIS): RL-AREA-AXIS: 3.82 ± 0.45 cm2; LL-AREA-AXIS: 3.87 ± 0.41 cm2; ventrodorsal (VD)-AREA-AXIS: 4.59 ± 0.64 cm2; and DV-AREA-AXIS: 4.80 ± 0.50 cm2 for males and RL-AREA-AXIS: 2.39 ± 0.23 cm2; LL-AREA-AXIS: 2.41 ± 0.26 cm2; VD-AREA-AXIS: 3.08 ± 0.45 cm2; and DV-AREA-AXIS: 3.06 ± 0.47 cm2 for females. The cardiac area open polygon (AREA-POL) values were: RL-AREA-POL: 6.78 ± 0.65 cm2; LL-AREA-POL: 6.88 ± 0.68 cm2; VD-AREA-POL: 7.20 ± 0.91 cm2; and DV-AREA-POL: 7.57 ± 0.88 cm2 for males and RL-AREA-POL: 4.28 ± 0.30 cm2; LL-AREA-POL: 4.35 ± 0.35 cm2; VD-AREA-POL: 4.72 ± 0.65 cm2; and DV-AREA-POL: 4.79 ± 0.66 cm2 for females, with similar differences noted from various radiographic projections. A good correlation was noted between VHS and SHS, and a very strongly positive correlation existed between cardiac area measurements and cardiac dimensions.Conclusion: The VHS adapted to ferrets, the SHS, as well as the cardiac area measurements presented in our study are ideal tools for the assessment of cardiac size in ferrets.

Facial and body sexual dimorphism are not interconnected in the Maasai

Background In this paper, we investigate facial sexual dimorphism and its’ association with body dimorphism in Maasai, the traditional seminomadic population of Tanzania. We discuss findings on other human populations and possible factors affecting the developmental processes in Maasai. Methods Full-face anthropological photographs were obtained from 305 Maasai (185 men, 120 women) aged 17–90 years. Facial shape was assessed combining geometric morphometrics and classical facial indices. Body parameters were measured directly using precise anthropological instruments. Results Sexual dimorphism in Maasai faces was low, sex explained 1.8% of the total shape variance. However, male faces were relatively narrower and vertically prolonged, with slightly wider noses, narrower-set and lower eyebrows, wider mouths, and higher forehead hairline. The most sexually dimorphic regions of the face were the lower jaw and the nose. Facial width-to-height ratio (fWHR), measured in six known variants, revealed no significant sexual dimorphism. The allometric effects on facial traits were mostly related to the face growth, rather than the growth of the whole body (body height). Significant body dimorphism was demonstrated, men being significantly higher, with larger wrist diameter and hand grip strength, and women having higher BMI, hips circumferences, upper arm circumferences, triceps skinfolds. Facial and body sexual dimorphisms were not associated. Conclusions Facial sex differences in Maasai are very low, while on the contrary, the body sexual dimorphism is high. There were practically no associations between facial and body measures. These findings are interpreted in the light of trade-offs between environmental, cultural, and sexual selection pressures.

Skull morphological variation in a British stranded population of false killer whale (Pseudorca crassidens): a three-dimensional geometric morphometric approach

The false killer whale (Pseudorca crassidens (Owen, 1846)) is a globally distributed delphinid that shows geographical differentiation in its skull morphology. We explored cranial morphological variation in a sample of 85 skulls belonging to a mixed sex population stranded in the Moray Firth, Scotland, in 1927. A three-dimensional digitizer (Microscribe 2GX) was used to record 37 anatomical landmarks on the cranium and 25 on the mandible to investigate size and shape variation and to explore sexual dimorphism using geometric morphometric. Males showed greater overall skull size than females, whereas no sexual dimorphism could be identified in cranial and mandibular shape. Allometric skull changes occurred in parallel for both males and females, supporting the lack of sexual shape dimorphism for this particular sample. Also, fluctuating asymmetry did not differ between crania of males and females. This study confirms the absence of sexual shape dimorphism and the presence of a sexual size dimorphism in this false killer whale population.

Sexual dimorphism in small-intestinal neuroendocrine tumors: lower prevalence of mesenteric disease in premenopausal women

Context Small intestinal neuroendocrine tumors (SI-NETs) have a modest but significantly higher prevalence and worse prognosis in male patients. Objective This work aims to increase understanding of this sexual dimorphism in SI-NETs. Patients and Methods Retrospectively, SI-NET patients treated in a single tertiary center were included and analyzed for disease characteristics. Estrogen receptor 1 (ESR1) and 2 (ESR2), progesterone receptor (PGR) and androgen receptor (AR) mRNA expression was assessed in primary tumors and healthy intestine. Estrogen receptor alpha (ERα) and AR protein expression was analyzed by immunohistochemistry in primary tumors and mesenteric metastases. Results Of the 559 patients, 47% were female. Mesenteric metastasis/fibrosis was more prevalent in men (71/46%) than women (58/37%, P=0.001 and P = 0.027). In women, prevalence of mesenteric metastases increased gradually with age from 41.1% in women <50 years to 71.7% in women >70 years. Increased expression of ESR1 and AR mRNA was observed in primary tumors compared to healthy intestine (both P < 0.001). ERα staining was observed in tumor cells and stroma with a strong correlation between tumor cells of primary tumors and mesenteric metastases (rho=0.831, P=0.02), but not in stroma (rho=-0.037, P=0.91). AR expression was only found in stroma. Conclusion Sexual dimorphism in SI-NETs was most pronounced in mesenteric disease and the risk of mesenteric metastasis in women increased around menopause. The combination of increased ERα and AR expression in the SI-NET microenvironment suggests a modulating role of sex steroids in the development of the characteristic SI-NET mesenteric metastasis and associated fibrosis.

Regulatory T Cells Contribute to Sexual Dimorphism in Neonatal Hypoxic-Ischemic Brain Injury

Background and Purpose: Neonatal encephalopathy caused by hypoxia-ischemia (HI) is a major cause of death and disability in newborns. Clinical and experimental studies suggest a sexual dimorphism in HI-induced brain injury and therapy responses. A major hallmark of HI pathophysiology is the infiltration of peripheral immune cells into the injured brain. However, the specific role of regulatory T cells (Tregs) in neonatal HI is still unknown. Methods: Nine-day-old mice were exposed to HI by ligation of the right common carotid artery followed by 1 hour hypoxia (10% oxygen). Using immunohistochemistry, flow cytometry, and microarray analyses, Tregs were investigated in the brain, spleen, and blood 24 hours post HI. The functional role of Tregs was evaluated by acute Treg depletion in depletion of regulatory T cells transgenic mice. Brain injury, neuroinflammatory responses, and vascular injury were analyzed via immunohistochemistry and Western blot 48 hours and 7 days after HI. Functional outcome was assessed 3 days and 5 weeks after HI. Results: Female mice revealed an increased cerebral Treg infiltration, coinciding with elevated chemokine receptor expression. Treg depletion in females aggravated HI-induced brain tissue injury, short-term motor deficits, and long-term deficits in exploratory activity, paralleled by an increased microglia and endothelial activation and leukocyte infiltration. Treg depletion in male mice reduced HI-induced brain injury, short-term motor, and long-term cognitive deficits, associated with reduced vascular injury. Ex vivo isolated female Tregs displayed an increased immunosuppressive activity on effector T cell proliferation and an increased gene enrichment in pathways related to enhanced Treg activity. Conclusions: Tregs from neonatal female mice provide endogenous neuroprotection, whereas Tregs from male mice increase secondary neurodegeneration. As potential mechanisms, we identified intrinsic transcriptional differences associated with enhanced anti-inflammatory activity of female Tregs. Our study emphasizes the urgent need for sex-stratified clinical and preclinical analyses.

Exploring Sexual Dimorphism in the Intestinal Microbiota of the Yellow Drum (Nibea albiflora, Sciaenidae)

Most of fish species exhibit striking sexual dimorphism, particularly during growth. There are also sexual dimorphisms of internal organs and biological functions, including those of intestinal microbiota, which likely plays a key role in growth. In this study, the growth and intestinal microbiota of the female, male, and all-female Nibea albiflora (yellow drums) were comprehensively analyzed. The caged culture female and all-female yellow drums showed higher growth rates than males. A further analysis of the intestinal microbiota showed a significant difference in diversity between females and males in the summer, whereas there were no significant differences in the diversity and richness between females and males in the winter. In contrast, a significant difference in richness was observed between all-female and male fish, regardless of the season. Although the main composition of the intestinal microbiota showed no significant sex differences, the community structure of the intestinal microbiota of yellow drums did. Furthermore, the correlations between intestinal microbial communities are likely to be influenced by sex. The ecological processes of the intestinal microbial communities of the yellow drums showed clear sexual dimorphism. Further network analysis revealed that, although the main components of the network in the intestinal microbiota of female, male, and all-female fish were similar, the network structures showed significant sex differences. The negative interactions among microbial species were the dominant relationships in the intestinal ecosystem, and Bacteroidetes, Firmicutes, and Proteobacteria were identified as the functional keystone microbes. In addition, the functional pathways in the intestinal microbiota of yellow drums showed no significant sexual or seasonal differences. Based on the findings of this study, we gain a comprehensive understanding of the interactions between sex, growth, and intestinal microbiota in yellow drums.