A role for a neo-sex chromosome in stickleback speciation.

Sexual antagonism, or conflict between the sexes, has been proposed as a driving force in both sex-chromosome turnover and speciation. Although closely related species often have different sex-chromosome systems, it is unknown whether sex-chromosome turnover contributes to the evolution of reproductive isolation between species. Here we show that a newly evolved sex chromosome contains genes that contribute to speciation in threespine stickleback fish (Gasterosteus aculeatus). We first identified a neo-sex chromosome system found only in one member of a sympatric species pair in Japan. We then performed genetic linkage mapping of male-specific traits important for reproductive isolation between the Japanese species pair. The neo-X chromosome contains loci for male courtship display traits that contribute to behavioural isolation, whereas the ancestral X chromosome contains loci for both behavioural isolation and hybrid male sterility. Our work not only provides strong evidence for a large X-effect on reproductive isolation in a vertebrate system, but also provides direct evidence that a young neo-X chromosome contributes to reproductive isolation between closely related species. Our data indicate that sex-chromosome turnover might have a greater role in speciation than was previously appreciated

Suppression of low-density lipoprotein oxidation, vascular smooth muscle cell proliferation and migration by a herbal extract of Radix Astragali, Radix Codonopsis and Cortex Lycii

<p>Abstract</p> <p>Background</p> <p>Atherosclerosis is a major cause of death in developed world. Atherosclerosis is characterized by low-density lipoprotein deposition in the arterial wall which ultimately begets the formation of lesions. Rupture of lesions finally leads to clinical events such as heart attack and stroke. Atherosclerosis is a complication associated with diabetes. In patients with diabetes, the risk of atherosclerosis is three to five folds greater than in non-diabetics. Our previous study showed that a herbal extract of <it>Radix Astragali, Radix Codonopsis </it>and <it>Cortex Lycii</it>, namely SR10, could improve glucose homeostasis both <it>in vitro </it>and <it>in vivo</it>. In this study, we want to further investigate the efficacy of SR10 in treating atherosclerosis.</p> <p>Method</p> <p>The inhibitory effect of SR10 on low-density lipoprotein oxidation was investigated using free radical-induced erythrocyte hemolysis model and copper ion-induced low-density lipoprotein oxidation model. Since vascular smooth muscle cell proliferation and migration are important processes in atherogenesis, we also examined the effect of SR10 in inhibiting these events.</p> <p>Results</p> <p>Our results showed that SR10 inhibited erythrocyte hemolysis with IC₅₀value at 0.25 mg/ml and significantly prolonged low-density lipoprotein oxidation <it>in vitro</it>. SR10 attenuated platelet derived growth factor-BB-induced vascular smooth muscle cell proliferation by promoting cell cycle arrest at G₀/G₁phase as well as inhibiting vascular smooth muscle cell migration.</p> <p>Conclusion</p> <p>The potential application of SR10 in treating atherosclerosis has been implied in this study. Animal model will be needed to further verify the efficacy of SR10 in future.</p

Psychological response of family members of patients hospitalised for influenza A/H1N1 in Oaxaca, Mexico

<p>Abstract</p> <p>Background</p> <p>The A/H1N1 pandemic originated in Mexico in April 2009, amid high uncertainty, social and economic disruption, and media reports of panic. The aim of this research project was to evaluate the psychological response of family primary caregivers of patients hospitalised in the Intensive Care Unit (ICU) with suspected influenza A/H1N1 to establish whether there was empirical evidence of high adverse psychological response, and to identify risk factors for such a response. If such evidence was found, a secondary aim was to develop a specific early intervention of psychological support for these individuals, to reduce distress and possibly lessen the likelihood of post-traumatic stress disorder (PTSD) in the longer term.</p> <p>Methods</p> <p>Psychological assessment questionnaires were administered to the family primary caregivers of patients hospitalised in the ICU in the General Hospital of Zone 1 of the Mexican Institute for Social Security (IMSS), Oaxaca, Mexico with suspected influenza A/H1N1, during the month of November 2009. The main outcome measures were ratings of reported perceived stress (PSS-10), depression (CES-D), and death anxiety (DAQ). Data were subjected to simple and multiple linear regression analysis to identify risk factors for adverse psychological response.</p> <p>Results</p> <p>Elevated levels of perceived stress and depression, compared to population normative data, and moderate levels of death anxiety were noted. Levels of depression were similar to those found in comparable studies of family members of ICU patients admitted for other conditions. Multiple regression analysis indicated that increasing age and non-spousal family relationship were significantly associated with depression and perceived stress. Female gender, increasing age, and higher levels of education were significantly associated with high death anxiety. Comparisons with data collected in previous studies in the same hospital ICU with groups affected by a range of other medical conditions indicated that the psychological response reported in this study was generally lower.</p> <p>Conclusions</p> <p>Data indicated that, contrary to widely publicised reports of 'panic' surrounding A/H1N1, that some of those most directly affected did not report excessive psychological responses; however, we concluded that there was sufficient evidence to support provision of limited psychological support to family caregivers.</p

Turnover of Sex Chromosomes in the Stickleback Fishes (Gasterosteidae)

Diverse sex-chromosome systems are found in vertebrates, particularly in teleost fishes, where different systems can be found in closely related species. Several mechanisms have been proposed for the rapid turnover of sex chromosomes, including the transposition of an existing sex-determination gene, the appearance of a new sex-determination gene on an autosome, and fusions between sex chromosomes and autosomes. To better understand these evolutionary transitions, a detailed comparison of sex chromosomes between closely related species is essential. Here, we used genetic mapping and molecular cytogenetics to characterize the sex-chromosome systems of multiple stickleback species (Gasterosteidae). Previously, we demonstrated that male threespine stickleback fish (Gasterosteus aculeatus) have a heteromorphic XY pair corresponding to linkage group (LG) 19. In this study, we found that the ninespine stickleback (Pungitius pungitius) has a heteromorphic XY pair corresponding to LG12. In black-spotted stickleback (G. wheatlandi) males, one copy of LG12 has fused to the LG19-derived Y chromosome, giving rise to an X1X2Y sex-determination system. In contrast, neither LG12 nor LG19 is linked to sex in two other species: the brook stickleback (Culaea inconstans) and the fourspine stickleback (Apeltes quadracus). However, we confirmed the existence of a previously reported heteromorphic ZW sex-chromosome pair in the fourspine stickleback. The sex-chromosome diversity that we have uncovered in sticklebacks provides a rich comparative resource for understanding the mechanisms that underlie the rapid turnover of sex-chromosome systems

Divergence in Sex Steroid Hormone Signaling between Sympatric Species of Japanese Threespine Stickleback

Sex steroids mediate the expression of sexually dimorphic or sex-specific traits that are important both for mate choice within species and for behavioral isolation between species. We investigated divergence in sex steroid signaling between two sympatric species of threespine stickleback (Gasterosteus aculeatus): the Japan Sea form and the Pacific Ocean form. These sympatric forms diverge in both male display traits and female mate choice behaviors, which together contribute to asymmetric behavioral isolation in sympatry. Here, we found that plasma levels of testosterone and 17β-estradiol differed between spawning females of the two sympatric forms. Transcript levels of follicle-stimulating hormone-β (FSHβ) gene were also higher in the pituitary gland of spawning Japan Sea females than in the pituitary gland of spawning Pacific Ocean females. By contrast, none of the sex steroids examined were significantly different between nesting males of the two forms. However, combining the plasma sex steroid data with testis transcriptome data suggested that the efficiency of the conversion of testosterone into 11-ketotestosterone has likely diverged between forms. Within forms, plasma testosterone levels in males were significantly correlated with male body size, a trait important for female mate choice in the two sympatric species. These results demonstrate that substantial divergence in sex steroid signaling can occur between incipient sympatric species. We suggest that investigation of the genetic and ecological mechanisms underlying divergence in hormonal signaling between incipient sympatric species will provide a better understanding of the mechanisms of speciation in animals

Molecular and cellular mechanisms underlying the evolution of form and function in the amniote jaw.

The amniote jaw complex is a remarkable amalgamation of derivatives from distinct embryonic cell lineages. During development, the cells in these lineages experience concerted movements, migrations, and signaling interactions that take them from their initial origins to their final destinations and imbue their derivatives with aspects of form including their axial orientation, anatomical identity, size, and shape. Perturbations along the way can produce defects and disease, but also generate the variation necessary for jaw evolution and adaptation. We focus on molecular and cellular mechanisms that regulate form in the amniote jaw complex, and that enable structural and functional integration. Special emphasis is placed on the role of cranial neural crest mesenchyme (NCM) during the species-specific patterning of bone, cartilage, tendon, muscle, and other jaw tissues. We also address the effects of biomechanical forces during jaw development and discuss ways in which certain molecular and cellular responses add adaptive and evolutionary plasticity to jaw morphology. Overall, we highlight how variation in molecular and cellular programs can promote the phenomenal diversity and functional morphology achieved during amniote jaw evolution or lead to the range of jaw defects and disease that affect the human condition

Practitioners' Perceptions of the Soccer Extra-Time Period: Implications for Future Research

Qualitative research investigating soccer practitioners’ perceptions can allow researchers to create practical research investigations. The extra-time period of soccer is understudied compared to other areas of soccer research. Using an open-ended online survey containing eleven main and nine sub questions, we gathered the perceptions of extra-time from 46 soccer practitioners, all working for different professional soccer clubs. Questions related to current practices, views on extra-time regulations, and ideas for future research. Using inductive content analysis, the following general dimensions were identified: ‘importance of extra-time’, ‘rule changes’, ‘efficacy of extra-time hydro-nutritional provision’, ‘nutritional timing’, ‘future research directions’, ‘preparatory modulations’ and ‘recovery’. The majority of practitioners (63%) either agreed or strongly agreed that extra-time is an important period for determining success in knockout football match-play. When asked if a fourth substitution should be permitted in extra-time, 67% agreed. The use of hydro-nutritional strategies prior to extra-time was predominately considered important or very important. However; only 41% of practitioners felt that it was the most important time point for the use of nutritional products. A similar number of practitioners account (50%) and do not (50%) account for the potential of extra-time when training and preparing players and 89% of practitioners stated that extra-time influences recovery practices following matches. In the five minute break prior to extra-time, the following practices (in order of priority) were advocated to players: hydration, energy provision, massage, and tactical preparations. Additionally, 87% of practitioners advocate a particular nutritional supplementation strategy prior to extra-time. In order of importance, practitioners see the following as future research areas: nutritional interventions, fatigue responses, acute injury risk, recovery modalities, training paradigms, injury epidemiology, and environmental considerations. This study presents novel insight into the practitioner perceptions of extra-time and provides information to readers about current applied practices and potential future research opportunities

High sensitivity organic inorganic hybrid X-ray detectors with direct transduction and broadband response

X-ray detectors are critical to healthcare diagnostics, cancer therapy and homeland security, with many potential uses limited by system cost and/or detector dimensions. Current X-ray detector sensitivities are limited by the bulk X-ray attenuation of the materials and consequently necessitate thick crystals (~1 mm-1 cm), resulting in rigid structures, high operational voltages and high cost. Here we present a disruptive, flexible, low cost, broadband, and high sensitivity direct X-ray transduction technology produced by embedding high atomic number bismuth oxide nanoparticles in an organic bulk heterojunction. These hybrid detectors demonstrate sensitivities of 1712 µC mGy-1 cm-3 for "soft" X-rays and ~30 and 58 µC mGy-1 cm-3 under 6 and 15 MV "hard" X-rays generated from a medical linear accelerator; strongly competing with the current solid state detectors, all achieved at low bias voltages (-10 V) and low power, enabling detector operation powered by coin cell batteries

Increasing genome instability in adrenocortical carcinoma progression with involvement of chromosomes 3, 9 and X at the adenoma stage

The investigation of chromosomal aberrations in adrenocortical tumours has been limited by the difficulties of applying classical cytogenetics to tumours with low levels of proliferation. We have therefore applied the technique of interphase cytogenetics to paraffin-embedded archival specimens of 14 adrenocortical adenomas and 13 carcinomas. Hybridizations were performed using centromere-specific probes to chromosomes 3, 4, 9, 17, 18 and X, which have been shown to be altered in other types of tumours. Chromosomal imbalance was defined on the basis of changes in both chromosome index (CI) and signal distribution (SD). Where only one of these was altered, this was classified as a tendency to gain or loss. On the basis of the analysis of optimal hybridizations, carcinomas showed gains in all chromosomes studied, five of nine showing gains in multiple chromosomes. Gains were most common in chromosomes 3, 9 and, in particular X, eight of 11 showing gain, and one a tendency to gain. Chromosomal gain was seen less commonly in adenomas, but again chromosomes 3, 9 and X were involved. Losses were infrequent, only one carcinoma showing loss of chromosome 18, and adenomas showing a tendency to loss of chromosomes 4 (two cases), 17 (one case) and 18 (two cases). Our data suggest that changes in chromosomes 3, 9 and X are early events in adrenocortical tumorigenesis, and that there is increasing chromosomal instability with tumour progression. © 1999 Cancer Research Campaig