131 research outputs found

    CRP-cAMP mediates silencing of Salmonella virulence at the post-transcriptional level

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    Invasion of epithelial cells by Salmonella enterica requires expression of genes located in the pathogenicity island I (SPI-1). The expression of SPI-1 genes is very tightly regulated and activated only under specific conditions. Most studies have focused on the regulatory pathways that induce SPI-1 expression. Here, we describe a new regulatory circuit involving CRP-cAMP, a widely established metabolic regulator, in silencing of SPI-1 genes under non-permissive conditions. In CRP-cAMP-deficient strains we detected a strong upregulation of SPI-1 genes in the mid-logarithmic growth phase. Genetic analyses revealed that CRP-cAMP modulates the level of HilD, the master regulator of Salmonella invasion. This regulation occurs at the post-transcriptional level and requires the presence of a newly identified regulatory motif within the hilD 3’UTR. We further demonstrate that in Salmonella the Hfq-dependent sRNA Spot 42 is under the transcriptional repression of CRP-cAMP and, when this transcriptional repression is relieved, Spot 42 exerts a positive effect on hilD expression. In vivo and in vitro assays indicate that Spot 42 targets, through its unstructured region III, the 3’UTR of the hilD transcript. Together, our results highlight the biological relevance of the hilD 3’UTR as a hub for post-transcriptional control of Salmonella invasion gene expression.Spanish Ministry of Economy and Competitiveness BIO2010-15417 BIO2013-44220-R AGL2013-45339-RRecerCaixa program 2012/ACUP/00048Catalonian government 2017SGR49

    Drivers of sex ratio bias in the eastern bongo: lower inbreeding increases the probability of being born male

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    Abstract Parent sex ratio allocation has consequences for individual fitness, population dynamics, and conservation. Theory predicts that parents should adjust offspring sex ratio when the fitness returns of producing male or female offspring varies. Previous studies have assumed that only mothers are capable of biasing offspring sex ratios, but have neglected fathers, given the expectation of an equal proportion of X- and Y-chromosome-bearing (CBS) sperm in ejaculates due to sex chromosome segregation at meiosis. This assumption has been recently refuted and both paternal fertility and paternal genetic quality have been shown to bias sex ratios. Here, we simultaneously test the relative contribution of paternal, maternal, and individual genetic quality, as measured by inbreeding, on the probability of being born a son or a daughter, using pedigree and lifelong offspring sex ratio data for the eastern bongo ( Tragelaphus eurycerus isaaci). Our models showed first, that surprisingly, as individual inbreeding decreases the probability of being born male increases, second, that paternal genetic effects on sex ratio were stronger than maternal genetic effects (which were absent). Furthermore, paternal effects were opposite in sign to those predicted; father inbreeding increases the probability of having sons. Previous paternal effects have been interpreted as adaptive due to sex-specific inbreeding depression for reproductive traits. We argue that in the eastern bongo, the opposite sign of the paternal effect on sex ratios results from a reversed sex-specific inbreeding depression pattern (present for female but not male reproductive traits). We anticipate that this research will help stimulate research on evolutionary constraints to sex ratios. Finally, the results open a new avenue of research to predict sex ratio allocation in an applied conservation context. Future models of sex ratio allocation should also include the predicted inbreeding level of the offspring and paternal inbreeding levels

    Benefits and pitfalls of captive conservation genetic management: evaluating diversity in scimitar-horned oryx to support reintroduction planning

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    The reintroduction of the scimitar-horned oryx to Chad is a multi-disciplinary endeavour, planned and implemented over the past decade, utilizing a wide range of conservation science applications to maximise the chances of long-term population sustainability. The principle of incorporating genetic diversity information into founder selection for species reintroductions is widely recognized; however, in practice, a full assessment of available ex-situ genetic variation is rarely attempted prior to identifying individuals for release.In this study we present the results of over ten years of research analyzing and interpreting the genetic diversity present in the key source populations for the Chad scimitar-horned oryx reintroduction. Three empirical genetic datasets (mitochondrial DNA sequence, nuclear DNA microsatellite and SNP markers) comprising over 500 individuals sampled from public and private institutions were analysed, accompanied by simulation studies to address applied questions relating to management of the reintroduction.The results strongly demonstrate the importance of conservation genetic analysis in ensuring that founders represent the greatest breadth of evolutionary diversity available. The inclusion of both intensively and lightly managed collections allowed us to bridge the gap between studbook and group managed populations, enabling the inclusion of individuals from populations that lack historic data on their origins, but which may hold unique diversity of significant conservation value. Importantly, however, our study also reveals the potential risks of applying standard population genetic approaches to multiple captive populations, for which small founder sizes are likely to strongly bias results, with potentially serious consequences for the genetic management of conservation breeding programmes

    Low-dose inoculation of Escherichia coli achieves robust vaginal colonization and results in ascending infection accompanied by severe uterine inflammation in mice

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    Escherichia coli infection of the female reproductive tract is a significant cause of disease in humans and animals, but simple animal models are lacking. Here we report that vaginal inoculation of uropathogenic E. coli strains UTI89 and CFT073 in non-pregnant, estrogen-treated mice resulted in robust colonization of the vagina and uterine horns, whereas titers of the lab strain MG1655 were significantly lower. Non-estrogenized mice also became colonized, but there was more variation in titers. A dose of 104 colony-forming units (CFU) UTI89 was sufficient to result in colonization in all estrogenized mice, and we also observed bacterial transfer between inoculated and uninoculated estrogenized cage mates. UTI89 infection led to inflammation and leukocyte infiltration into the uterine horns as evidenced by tissue histology. Flow cytometry experiments revealed that neutrophil, monocyte and eosinophil populations were significantly increased in infected uterine horns. This model is a simple way to study host-pathogen interactions in E. coli vaginal colonization and uterine infection. There are immediate implications for investigators studying urinary tract infection using mouse models, as few E. coli are required to achieve reproductive colonization, resulting in an additional, underappreciated mucosal reservoir

    Sperm gatekeeping : 3D imaging reveals a constricted entrance to zebra finch sperm storage tubules

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    Females across many internally fertilizing taxa store sperm, often in specialized storage organs in their reproductive tracts. In birds, several hundred sperm storage tubules exist in the utero-vaginal junction of the oviduct, and there is growing evidence that sperm storage in these tubules is selective. The mechanisms underlying female sperm storage in birds remain unknown because of our limited ability to make three-dimensional, live observations inside the large, muscular avian oviduct. Here, we describe a new application of fluorescence selective plane illumination microscopy to optically section oviduct tissue from zebra finch Taeniopygia guttata females label free by harnessing tissue autofluorescence. Our data provide the first description of the three-dimensional structure of sperm storage organs in any vertebrate to the best of our knowledge and reveal the presence of gate-like constricted openings that may play a role in sperm selection

    Ensayo de biocompatibilidad con Artemia salina para cinco materiales de uso endodóntico

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    Introduction: Biocompatibility is a decisive factor in the success of endodontic therapy. Objective: to assess the cytotoxicity of five endodontic materials using the Artemia salina test. Method: an in vitro experimental study was designed, using Artemia salina, to evaluate the biocompatibility of Grossman, CaOH, AH-Plus, MTA, and TheraCal-LC cements, with observations at 24 and 48 hours. Results: The results indicate that Grossman cement presents 100% toxicity at 24 hours, while the other materials show values lower than 30%, reflecting a biocompatible behavior; however, at 48 hours, CaOH and TheraCal-LC present toxicity higher than 30%, while AH-Plus and MTA continue with values lower than 30%. The data were analyzed with a Generalized Linear Model with binomial error distribution, a deviancy analysis, and Fisher's multiple comparison test with Bonferroni correction. An independent analysis was performed for 24 and 48 hours, under a significance level α=5%; significant differences were found at 48 hours between TheraCal-LC and AH-Plus, and MTA. Conclusion: It is concluded that Grossman cement presented a high degree of toxicity, while AH-Plus and MTA showed the highest biocompatibility.Introducción: la biocompatibilidad es un factor decisivo para el éxito de una terapia endodoncica. Objetivo: evaluar la citotoxicidad de cinco materiales de uso endodóntico mediante la prueba de Artemia Salina. Método: se diseñó un estudio experimental in vitro, empleando Artemia salina, para evaluar la biocompatibilidad de los cementos Grossman, CaOH, AH-Plus, MTA y TheraCal-LC con observaciones a 24 y 48 horas. Resultados: los resultados indican que el cemento Grossman presenta un 100% de toxicidad a las 24 horas, mientras que los demás materiales muestran valores menores al 30%, reflejando un comportamiento biocompatible, sin embargo, a las 48 horas, CaOH y TheraCal-LC presentan una toxicidad mayor al 30%, mientras que AH-Plus y MTA continúan con valores -menores del 30%. Los datos fueron analizados con un Modelo lineal generalizado con distribución de errores binomial, un análisis de devianza, y la prueba de comparación múltiple de Fisher con corrección Bonferroni.  Se hizo un análisis independiente para las 24 y 48 horas, bajo un nivel de significancia α=5%, se encontraron diferencias significativas a las 48 horas entre TheraCal-LC y AH-Plus y MTA. Conclusión: se concluye que el cemento Grossman presentó un alto grado de toxicidad, mientras que AH-Plus y MTA mostraron la mayor biocompatibilida

    Short-Term Compassion Training Increases Prosocial Behavior in a Newly Developed Prosocial Game

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    Compassion has been suggested to be a strong motivator for prosocial behavior. While research has demonstrated that compassion training has positive effects on mood and health, we do not know whether it also leads to increases in prosocial behavior. We addressed this question in two experiments. In Experiment 1, we introduce a new prosocial game, the Zurich Prosocial Game (ZPG), which allows for repeated, ecologically valid assessment of prosocial behavior and is sensitive to the influence of reciprocity, helping cost, and distress cues on helping behavior. Experiment 2 shows that helping behavior in the ZPG increased in participants who had received short-term compassion training, but not in participants who had received short-term memory training. Interindividual differences in practice duration were specifically related to changes in the amount of helping under no-reciprocity conditions. Our results provide first evidence for the positive impact of short-term compassion training on prosocial behavior towards strangers in a training-unrelated task

    Knowledge, attitudes, and practices related to COVID-19 in Indonesia: A post delta variant wave cross-sectional study

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    IntroductionPublic information and regulations related to the coronavirus disease 2019 (COVID-19) have been widely published and continuously changed. The Indonesian government has responded to the emerging evidence by regularly updating its unprecedented and preventive measures against the transmission of COVID-19 to the public. It is important to understand how the public responded to these updates. This study aimed to investigate the knowledge, attitudes, and practices of Indonesians toward COVID-19 after the emergence of the delta variant wave.MethodsA cross-sectional study was conducted among the adult population of non-healthcare workers in Indonesia through an online questionnaire using the SurveyMonkey platform. A total of 1,859 respondents completed this survey from September to October 2021. The knowledge, attitudes, and practices data were analyzed descriptively to find their frequency and percentage. A multivariate analysis was conducted to confirm the factors affecting the respondents' knowledge, attitudes, and practices with a p-value of <0.05 set as significant.ResultsBeing female, having a higher education level, and having a higher frequency of access to COVID-19 news showed significant impacts on knowledge, attitudes, and practices (p<0.001). Older age stratification influenced the knowledge level (p<0.05) but had no significant effect on people's attitudes and practices toward COVID-19. Respondents' perceived probability of being exposed to COVID-19 (p < 0.05) and their COVID-19 infection frequency (p < 0.001) significantly influenced their knowledge. Household income and respondents' knowledge significantly affected their attitudes toward COVID-19. Furthermore, only their attitudes had a significant impact on the respondents' practices. Perceived severity, perceived susceptibility, and vaccination status did not significantly influence their knowledge, attitudes, and practices (p > 0.05).ConclusionAfter more than a year of the COVID-19 pandemic, Indonesians maintain their high level of knowledge, attitudes, and practices. COVID-19 disinformation must be combatted by strengthening authorized media, empowering communities, and improving governance among institutions during and post-pandemic
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