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Effect of space flight factors on incidence of sex linked recessive lethal mutations in flies
Abstract Tau positron emission tomography (PET) imaging allows in vivo detection of tau proteinopathy in Alzheimer’s disease, which is associated with neurodegeneration and cognitive decline. Understanding how demographic, clinical and genetic factors relate to tau PET positivity will facilitate its use for clinical practice and research. Here we conducted an analysis of 42 cohorts worldwide (N = 12,048), including 7,394 cognitively unimpaired (CU) participants, 2,177 participants with mild cognitive impairment (MCI) and 2,477 participants with dementia. We found that from age 60 years to 80 years, tau PET positivity in a temporal composite region increased from 1.1% to 4.4% among CU amyloid-β (Aβ)-negative participants and from 17.4% to 22.2% among CU Aβ-positive participants. Across the same age span, tau PET positivity decreased from 68.0% to 52.9% in participants with MCI and from 91.5% to 74.6% in participants with dementia. Age, Aβ status,APOEε4 carriership and female sex were all associated with a higher prevalence of tau PET positivity across groups.APOEε4 carriership in CU individuals lowered the age at onset of both Aβ positivity and tau positivity by decades. Finally, we replicated these associations in an independent autopsy dataset (N = 5,072 from 3 cohorts).
Abstract As life history diversity plays a critical role in supporting the resilience of exploited populations, understanding the genetic basis of those life history variations is important for conservation management. However, effective application requires a robust understanding of the strength and universality of genetic associations. Here, we examine genetic variation of single nucleotide polymorphisms in genomic regions previously associated with migration phenology and age‐at‐maturity in steelhead ( Oncorhynchus mykiss ) from the Columbia River. We found chromosome 28 markers (GREB1L, ROCK1 genes) explained significant variance in migration timing in both coastal and inland steelhead. However, strength of association was much greater in coastal than inland steelhead ( R 2 0.51 vs. 0.08), suggesting that genomic background and challenging inland migration pathways may act to moderate effects of this region. Further, we found that chromosome 25 candidate markers (SIX6 gene) were significantly associated with age and size at first return migration for inland steelhead, and this pattern was mediated by sex in a predictable pattern (males R 2 = 0.139–0.170; females R 2 = 0.096–0.111). While this encourages using these candidate regions in predicting life history characteristics, we suggest that stock‐specific associations and haplotype frequencies will be useful in guiding implementation of genetic assays to inform management.
Moss sex chromosomes retain thousands of broadly expressed genes despite millions of years of suppressed recombination.
Candidate Phyla Radiation bacteria are emerging members of the human microbiota, particularly in oral and gut environments. Saccharibacteria were previously identified in the gut microbiota of healthy individuals and women diagnosed with familial Mediterranean fever (FMF), a monogenic autoinflammatory disorder prevalent in the eastern Mediterranean region, including Armenia. This study aimed to assess the prevalence and diversity of Saccharibacteria spp. and its basebiont Schaalia odontolytica in FMF patients, explore gender differences, and evaluate the modulation potential of two locally produced probiotics: Lactobacillus acidophilus INMIA9602 Er317/402 (Narine®, VITAMAX-E, Yerevan, Armenia) and Escherichia coli M-17 (Colibacteron®, VITAMAX-E, Yerevan, Armenia). The abundance and behavior of saccharibacteria and S. odontolytica appear to vary depending on health status and sex. Placebo administration caused both quantitative and qualitative shifts, suggesting a possible interaction between Candidatus saccharibacteria spp. and Schaalia odontolytica, though the underlying biological significance remains to be clarified. Narine administration appeared to increase the abundance of Candidatus saccharibacteria operational taxonomic units (OTUs) in FMF women and S. odontolytica OTUs in FMF men, whereas Colibacteron selectively decreased certain OTUs, predominantly in FMF women. These findings underscore the need to further investigate saccharibacteria’s role in systemic inflammation and probiotic-mediated modulation of the gut microbiota.
Heredity and cytology of sex as examined in frogs
Sex hormone uptake localization in brains of rats determined with high spatial resolution by autoradiography, using tritiated testosterone and estradiol
Sex differences in rat body weight regulation due to lateral hypothalamic lesions
The influence of orchiectomy (GDX) and steroid administration on the level of the cytosolic androgen receptor in the rat levator ani muscle and in rat skeletal muscles (tibialis anterior and extensor digitorum longus) was studied. Androgen receptor binding to muscle cytosol was measured using H-3 methyltrienolone (R1881) as ligand, 100 fold molar excess unlabeled R1881 to assess nonspecific binding, and 500 fold molar excess of triamcinolone acetonide to prevent binding to glucocorticoid and progestin receptors. Results demonstrate that modification of the levels of sex steroids can alter the content of androgen receptors of rat striated muscle. Data suggest that: (1) cytosolic androgen receptor levels increase after orchiectomy in both levator ani muscle and skeletal muscle; (2) the acute increase in receptor levels is blocked by an inhibitor of protein synthesis; and (3) administration of estradiol-17 beta to castrated animals increases receptor binding in levator ani muscle but not in skeletal muscle.
The effects of age and sex on the human-body responses to -50 torr LBNP were investigated in subjects who have undergone LBNP tests at the Kennedy Space Center. The comparison of results obtained on women and age-matched men indicated that men had larger relative increases in calf circumference and greater increases in peripheral resistance during the exposure to LBNP than the women; on the other hand, women displayed greater increases in thoracic impedance and heart rate. The comparison of the results on men of different ages (between 29 and 56 y) indicated that older subjects had greater increases in peripheral resistance and less heart rate elevation in response to LBNP. It is suggested that the age-related circulatory differences were due to a reduction in vagal response and a switch to predominant sympathetic nervous system influence in older men.
During initial exposure and adaptation to the microgravity environment, adult mammals exhibit elevated stress, mediated by the Hypothalamic-Pituitary-Adrenal (HPA) axis. In our previous studies of pregnant rats exposed to 2-g hypergravity via continuous centrifugation, we reported changes in neuroendocrine profiles including decreased corticosterone and a concomitant increase in body mass and leptin in adult male offspring. Prenatally stressed adult offspring have been shown to exhibit an elevated stress response in adulthood, therefore we hypothesized that these changes resulted from stress exposure during fetal development. Future studies examining reproduction, gestation, and development on-orbit need to consider the unique stressors of vehicle launch, the space environment, and landing on the development of the HPA axis in animals born and raised in microgravity. In this study, we utilize Unpredictable Variable Prenatal Stress (UVPS) to simulate the stressors of spaceflight by exposing dams to three different stressors: (1) White Noise, (2) Strobe Light, and (3) Tube Restraint. Stressors were applied from Gestational Day 0 (G0), following an unpredictable schedule (morning [0600-1200hrs]; afternoon [1200-1800hrs]; evening [1800-2400hrs] in 15, 30, or 60 minute durations alongside non-stressed (NS) control dams. Following parturition, pups were fostered to non-manipulated, newly parturient dams to control for differential maternal care. On postnatal day 90 (P90), we harvested the hypothalamus, pituitary, and adrenal glands, and analyzed mRNA expression of the following genes via RT-qPCR: 1) melanocortin-2 receptor (MC2R), POMC, corticotropin-releasing hormone (CRH) in the pituitary; 2) glucocorticoid receptor (NR3C1), pro-opiomelanocortin (POMC), corticotropin-releasing hormone (CRH), brain-derived neurotropic factor (BDNF), in the hypothalamus; and 3) MC2R, tyrosine hydroxylase (TH), steroidogenic acute regulatory protein (STAR), cytochrome P450scc enzyme (CYP) in the adrenal. The identification of sex-specific fetal programming effects on adult stress response is a key step in determining potential animal behavior on-orbit, and will guide future multi-generational studies in microgravity.
Rural regions of the western United States have experienced a noticeable surge in both the frequency and severity of acute wildfire events, which brings significant challenges to both public safety and environmental conservation efforts, with impacts felt globally. Identifying factors contributing to immune dysfunction, including endocrinological phenotypes, is essential to understanding how hormones may influence toxicological susceptibility.
Microorganisms in the gut of a cockroach resemble those that lived on earth 2000 million years ago. One of their activities, eating each other, may hold the key to the history of sexual reproduction in today's animals and plants.
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