scholarly journals Estrogenic induction of spermatogenesis in the hypogonadal (hpg) mouse: role of androgens

Reproduction ◽  
2005 ◽  
Vol 130 (5) ◽  
pp. 643-654 ◽  
Author(s):  
Helen Baines ◽  
Margaret O Nwagwu ◽  
Edwina C Furneaux ◽  
Jane Stewart ◽  
Jeffrey B Kerr ◽  
...  
Keyword(s):  
Seminal Vesicles ◽  
Testicular Development ◽  
Direct Effects ◽  
Estradiol Treatment ◽  
Hormone Synthesis ◽  
Androgen Receptor Antagonist ◽  
Congenital Deficiency ◽  
Testicular Weight ◽  
Normal Spermatogenesis

Testicular development is arrested in the hypogonadal (hpg) mouse due to a congenital deficiency of hypothalamic gonadotropin-releasing hormone synthesis. Previous studies have demonstrated that chronic treatment of these mice with estradiol induces testicular maturation and qualitatively normal spermatogenesis, but it is not known whether these are direct effects via estrogen receptors expressed in the testis, or indirect actions via the pituitary gland. The aim of the current studies was to determine whether the actions of estradiol require the presence of androgens. Sensitive assays revealed that chronic estradiol treatment produced time-dependent increases in pituitary FSH production but no increases in pituitary LH or testicular testosterone content could be detected. As a functional test of androgen dependence, hpg mice were treated for 70 days with estradiol plus Casodex (bicalutamide), an androgen receptor antagonist. Casodex treatment markedly attenuated both the estradiol-induced increase in testicular weight and the proliferation of the seminiferous epithelium, as revealed by morphometric analysis. However, it did not affect the estradiol-induced increase in pituitary FSH content, nor did it affect estradiol-induced increases in the weight of the seminal vesicles and epididymides. We conclude that increased FSH production is not sufficient to explain the increase in testicular development induced by estradiol in hpg mice; there is a requirement for functional androgen receptors for induction of testicular growth.

scholarly journals Characterization of N6-Methyladenosine in Domesticated Yak Testes Before and After Sexual Maturity

2021 ◽  
Vol 9 ◽  
Author(s):  
Xingdong Wang ◽  
Jie Pei ◽  
Shaoke Guo ◽  
Mengli Cao ◽  
Pengjia Bao ◽  
...  
Keyword(s):  
Sexual Maturation ◽  
Testicular Tissue ◽  
Notch Signaling Pathway ◽  
Regulatory Role ◽  
Testicular Development ◽  
Hormone Synthesis ◽  
Before And After ◽  
Rna Immunoprecipitation

The potential regulatory role of N6-methyladenosine (m6A), the most prominent mRNA modification in eukaryotes, has recently been identified in mammals, plants, and yeast. However, whether and how m6A methylation is involved in sexual maturation in mammals remains largely unexplored. In this study, testicular tissue was obtained from yaks before and after sexual maturation, and m6A maps were generated via preliminary experiments and methylated RNA immunoprecipitation sequencing. Only spermatogonial cells and a few primary spermatocytes were observed in the testicular tissue of yaks before sexual maturation, while spermatogenic cells at different stages of maturity could observed after sexual maturation. Experiments examining the expression of methylation-related enzymes and overall methylation levels showed that the methylation levels in yak testes increased after sexual maturation. Overall, 1,438 methylation peaks were differentially expressed before and after sexual maturation; 1,226 showed significant up-regulation and 212 showed significant down-regulation after sexual maturation. Annotation analysis showed that the differential methylation peaks were most commonly concentrated in the exon region, followed by the 3′UTR and finally the 5′UTR region. KEGG pathway analysis demonstrated that homologous recombination, the Notch signaling pathway, growth hormone synthesis, and other signaling pathways may be involved in testicular development and maturation in yaks. Levels of most m6A modifications were positively correlated with mRNA abundance, suggesting that m6A plays a regulatory role in mammalian sexual maturation. To our knowledge, this is the first report of an m6A transcriptional map of the yak testes, and our study lays the foundation for elucidating the function of m6A in the development of yak testes.

scholarly journals The Role of Flexibility in the Realization of Inclusive Education

2021 ◽  
Vol 13 (8) ◽  
pp. 4452
Author(s):  
Laura Lübke ◽  
Martin Pinquart ◽  
Malte Schwinger
Keyword(s):  
Social Skills ◽  
Inclusive Education ◽  
Learning Difficulties ◽  
Social Benefits ◽  
Direct Effects ◽  
Behavioral Disturbances ◽  
Teachers Attitudes ◽  
And Behavior ◽  
Mainstream Students

This study focused on associations between teachers’ flexibility and their use of evidence-based strategies in inclusive education in a sample of N = 119 teachers. Flexibility showed direct effects on teachers’ attitudes towards the achievement of mainstream students and students with learning difficulties, attitudes towards social benefits of inclusion for students with emotional and behavioral disturbances, and on teachers’ self-efficacy regarding the support of students’ social skills. Furthermore, indirect effects of flexibility on intentions and behavior regarding the support of social skills were found. The findings emphasize the importance of teachers’ flexibility in the realization of inclusive education.

scholarly journals Genetic Architecture of Testis and Seminal Vesicle Weights in Mice

Genetics ◽  
2001 ◽  
Vol 158 (1) ◽  
pp. 333-340 ◽  
Author(s):  
Isabelle Le Roy ◽  
Sylvie Tordjman ◽  
Danièle Migliore-Samour ◽  
Hervé Degrelle ◽  
Pierre L Roubertoux
Keyword(s):  
Seminal Vesicle ◽  
Inbred Strains ◽  
Genome Scan ◽  
Reproductive Organ ◽  
Seminal Vesicles ◽  
Total Variance ◽  
Chromosome 4 ◽  
Lod Score ◽  
Quantitative Genetic ◽  
Testicular Weight

Abstract Comparisons across 13 inbred strains of laboratory mice for reproductive organ (paired seminal vesicles and paired testes) weights indicated a very marked contrast between the C57BL/6By and NZB/BINJ mice. Subsequently these strains were selected to perform a quantitative genetic analysis and full genome scan for seminal vesicle and testis weights. An F2 population was generated. The quantitative genetic analyses indicated that each was linked to several genes. Sixty-six short sequences for length polymorphism were used as markers in the wide genome scan strategy. For weight of paired testes, heritability was 82.3% of the total variance and five QTL contributed to 72.8% of the total variance. Three reached a highly significant threshold (>4.5) and were mapped on chromosome X (LOD score 9.11), chromosome 4 (LOD score 5.96), chromosome 10 (LOD score 5.81); two QTL were suggested: chromosome 13 (LOD score 3.10) and chromosome 18 (LOD score 2.80). Heritability for weight of seminal vesicles was 50.7%. One QTL was mapped on chromosome 4 (LOD score 9.21) and contributed to 24.2% of the total variance. The distance of this QTL to the centromere encompassed the distance of the QTL linked with testicular weight on chromosome 4, suggesting common genetic mechanisms as expected from correlations in the F2. Both testis and seminal vesicle weights were associated with a reduction in the NZB/BINJ when this strain carried the YNPAR from CBA/H whereas the YNPAR from NZB/BINJ in the CBA/H strain did not modify reproductive organ weights, indicating that the YNPAR interacts with the non-YNPAR genes. The effects generated by this chromosomal region were significant but small in size.

The Role of Predation in Determining Traits of Aedes aegypti (Diptera: Culicidae) and Infection With Zika Virus

2021 ◽  
Author(s):  
Shawna Bellamy ◽  
Barry W Alto
Keyword(s):  
Aedes Aegypti ◽  
Zika Virus ◽  
Life History Traits ◽  
Immature Stages ◽  
Direct Effects ◽  
Infected Blood ◽  
Predator Prey ◽  
Susceptibility To Infection ◽  
Density Reduction

Abstract Non-lethal predator-prey interactions during the immature stages can cause significant changes to mosquito life history traits and their ability to transmit pathogens as adults. Treatment manipulations using mosquitoes Aedes aegypti (L.) and Toxoryhnchites rutilus (Coquillett) were performed during the immature stages to explore the potential impacts of non-lethal interactions on adult susceptibility to infection, disseminated infection and saliva infection of Ae. aegypti following ingestion of Zika virus-infected blood. Treatments inducing density reduction resulted in reduced development time and survivorship to adulthood. However, effects of treatment did not alter infection, dissemination, or saliva infection. These observations indicate that, while non-lethal predation may impact some traits that influence population dynamics and transmission of pathogens, there were no direct effects on mosquito-arbovirus interactions.

scholarly journals Enhanced Sexual Behaviors and Androgen Receptor Immunoreactivity in the Male Progesterone Receptor Knockout Mouse

Endocrinology ◽  
2005 ◽  
Vol 146 (10) ◽  
pp. 4340-4348 ◽  
Author(s):  
Johanna S. Schneider ◽  
Carly Burgess ◽  
Nicole C. Sleiter ◽  
Lydia L. DonCarlos ◽  
John P. Lydon ◽  
...  
Keyword(s):  
Sexual Behavior ◽  
Androgen Receptor ◽  
Progesterone Receptor ◽  
Sexual Behaviors ◽  
Gene Deletion ◽  
Biological Significance ◽  
Receptor Expression ◽  
Androgen Receptor Expression ◽  
Testicular Development ◽  
Testicular Weight

Reproductive and behavioral functions of progesterone receptors (PRs) in males were assessed by examining consequences of PR gene deletion. Basal hormone levels were measured in male progesterone receptor knockout (PRKO) mice and compared to wild-type (WT) counterparts. RIA of serum LH, testosterone, and progesterone levels revealed no significant differences. Levels of FSH were moderately but significantly lower and inhibin levels were higher in PRKOs; these differences were not accompanied by gross differences in testicular weight or morphology. PRKOs exhibited significant alterations in sexual behavior. In initial tests PRKOs exhibited reduced latency to mount, compared with WT. In second sessions, PRKOs again showed a significantly reduced latency to mount and increased likelihood of achieving ejaculation. RU486 treatment in WT produced increased mount and intromission frequency and decreased latency to intromission. In anxiety-related behavior tests, PRKO mice exhibited intermediate anxiety levels, compared with WT, suggesting that enhanced sexual behavior in PRKOs is not secondary to reduced anxiety. Immunohistochemical analysis revealed significantly enhanced androgen receptor expression in the medial preoptic nucleus and bed nucleus of the stria terminalis of PRKO. We conclude that testicular development and function and homeostatic regulation of the hypothalamic-pituitary testicular axis are altered to a lesser extent by PR gene deletion. In contrast, PR appears to play a substantial role in inhibiting the anticipatory/motivational components of male sexual behavior in the mouse. The biological significance of this inhibitory mechanism and the extent to which it is mediated by reduced androgen receptor expression remain to be clarified.

scholarly journals Trust in the European Union: Effects of the information environment

2018 ◽  
Vol 34 (1) ◽  
pp. 57-73 ◽  
Author(s):  
Anna Brosius ◽  
Erika J van Elsas ◽  
Claes H de Vreese
Keyword(s):  
European Union ◽  
Content Analysis ◽  
Survey Data ◽  
News Media ◽  
Information Environment ◽  
Direct Effects ◽  
The European Union ◽  
The Past ◽  
The Media

Over the past decade, the European Union has lost the trust of many citizens. This article investigates whether and how media information, in particular visibility and tonality, impact trust in the European Union among citizens. Combining content analysis and Eurobarometer survey data from 10 countries between 2004 and 2015, we study both direct and moderating media effects. Media tone and visibility have limited direct effects on trust in the European Union, but they moderate the relation between trust in national institutions and trust in the European Union. This relation is amplified when the European Union is more visible in the media and when media tone is more positive towards the European Union, whereas it is dampened when media tone is more negative. The findings highlight the role of news media in the crisis of trust in the European Union.

scholarly journals The influence of hypercapnia and the infaunal brittlestar <i>Amphiura filiformis</i> on sediment nutrient flux – will ocean acidification affect nutrient exchange?

2009 ◽  
Vol 6 (10) ◽  
pp. 2015-2024 ◽  
Author(s):  
H. L. Wood ◽  
S. Widdicombe ◽  
J. I. Spicer
Keyword(s):  
Atmospheric Carbon Dioxide ◽  
Marine Invertebrates ◽  
Nutrient Flux ◽  
Additional Treatment ◽  
Direct Effects ◽  
Exposure Study ◽  
Physicochemical Changes ◽  
Amphiura Filiformis ◽  
The Impact

Abstract. Rising levels of atmospheric carbon dioxide and the concomitant increased uptake of this by the oceans is resulting in hypercapnia-related reduction of ocean pH. Research focussed on the direct effects of these physicochemical changes on marine invertebrates has begun to improve our understanding of impacts at the level of individual physiologies. However, CO2-related impairment of organisms' contribution to ecological or ecosystem processes has barely been addressed. The burrowing ophiuroid Amphiura filiformis, which has a physiology that makes it susceptible to reduced pH, plays a key role in sediment nutrient cycling by mixing and irrigating the sediment, a process known as bioturbation. Here we investigate the role of A. filiformis in modifying nutrient flux rates across the sediment-water boundary and the impact of CO2- related acidification on this process. A 40 day exposure study was conducted under predicted pH scenarios from the years 2100 (pH 7.7) and 2300 (pH 7.3), plus an additional treatment of pH 6.8. This study demonstrated strong relationships between A. filiformis density and cycling of some nutrients;

scholarly journals National Identification and Collective Emotions as Predictors of Pro-Social Attitudes Toward Islamic Minority Groups in Indonesia

2014 ◽  
Vol 10 (2) ◽  
pp. 255-276 ◽  
Author(s):  
Ali Mashuri ◽  
Esti Zaduqisti
Keyword(s):  
Minority Groups ◽  
Social Attitudes ◽  
Direct Effects ◽  
Collective Guilt ◽  
Collective Emotions ◽  
National Identification ◽  
Group Data ◽  
Research Findings ◽  
Shed Light

The present study examined the role of Indonesian Moslem majority’s national identification, collective emotions of pride and guilt in predicting their support in helping members of Islamic minority and their perceived inclusion towards this group. Data from this study (N= 182) demonstrated that, in line with our prediction, support for minority helping significantly predicted perceived inclusion. We also hypothesized and found that collective pride and collective guilt directly predicted the minority helping. Finally, national identification had significant direct effects on both collective pride and collective guilt. These findings shed light on the importance of collective emotions and national identification in giving rise to pro-social attitudes of Indonesian Moslem majority towards members of Islamic minority. Implications of the research findings were discussed with reference to theories of group-based emotion and intergroup helping, and to practical strategies Indonesian government can apply to recognize Islamic minorities.

The Role of Ectomycorrhizal Symbiosis in the Resistance of Forests to Water Stress

2000 ◽  
Vol 29 (1) ◽  
pp. 63-69 ◽  
Author(s):  
Jean Garbaye
Keyword(s):  
Water Stress ◽  
Sustainable Management ◽  
Fine Roots ◽  
Forest Ecosystems ◽  
Water Status ◽  
Forest Trees ◽  
Direct Effects ◽  
Ectomycorrhizal Symbiosis ◽  
Protection Mechanisms

Forest trees live in enforced symbiosis with specialized fungi that form composite organs (ectomycorrhizas) with fine roots. This paper examines how this association contributes to the water status of trees and how it plays a major role in the protection mechanisms by which trees and forest stands resist drought-induced water stress. It shows how ectomycorrhizal symbiosis has both direct effects (at the uptake level) and indirect effects (at the regulation level) on the water status of trees. The facts presented are discussed in terms of forest adaptation to changing environmental conditions and the practical consequences for the sustainable management of forest ecosystems.

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