104 research outputs found

    MicroRNA regulation of the paired-box transcription factor Pax3 confers robustness to developmental timing of myogenesis

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    Commitment of progenitors in the dermomyotome to myoblast fate is the first step in establishing the body musculature. Pax3 is a crucial transcription factor, important for skeletal muscle development and expressed in myogenic progenitors in the dermomyotome of developing somites and in migratory muscle progenitors that populate the limb buds. Down-regulation of Pax3 is essential to ignite the myogenic program, including up-regulation of myogenic regulators, Myf-5 and MyoD. MicroRNAs (miRNAs) confer robustness to developmental timing by posttranscriptional repression of genetic programs that are related to previous developmental stages or to alternative cell fates. Here we demonstrate that the muscle-specific miRNAs miR-1 and miR-206 directly target Pax3. Antagomir-mediated inhibition of miR-1/miR-206 led to delayed myogenic differentiation in developing somites, as shown by transient loss of myogenin expression. This correlated with increased Pax3 and was phenocopied using Pax3-specific target protectors. Loss of myogenin after antagomir injection was rescued by Pax3 knockdown using a splice morpholino, suggesting that miR-1/miR-206 control somite myogenesis primarily through interactions with Pax3. Our studies reveal an important role for miR-1/miR-206 in providing precision to the timing of somite myogenesis. We propose that posttranscriptional control of Pax3 downstream of miR-1/miR-206 is required to stabilize myoblast commitment and subsequent differentiation. Given that mutually exclusive expression of miRNAs and their targets is a prevailing theme in development, our findings suggest that miRNA may provide a general mechanism for the unequivocal commitment underlying stem cell differentiation

    Eyewitness Identification and the Accuracy of the Criminal Justice System

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    This article addresses the problem of eyewitness identification errors that can lead to false convictions of the innocent and false acquittals of the guilty. At the heart of our analysis based on signal detection theory is the separation of diagnostic accuracy—the ability to discriminate between those who are guilty versus those who are innocent—from the consideration of the relative costs associated with different kinds of errors. Application of this theory suggests that current recommendations for reforms have conflated diagnostic accuracy with the evaluation of costs in such a way as to reduce the accuracy of identification evidence and the accuracy of adjudicative outcomes. Our framework points to a revision in recommended procedures and a framework for policy analysis.Yeshttps://us.sagepub.com/en-us/nam/manuscript-submission-guideline

    Transcriptomic Analyses Reveal Novel Genes with Sexually Dimorphic Expression in the Zebrafish Gonad and Brain

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    Background Our knowledge on zebrafish reproduction is very limited. We generated a gonad-derived cDNA microarray from zebrafish and used it to analyze large-scale gene expression profiles in adult gonads and other organs. Methodology/Principal Findings We have identified 116638 gonad-derived zebrafish expressed sequence tags (ESTs), 21% of which were isolated in our lab. Following in silico normalization, we constructed a gonad-derived microarray comprising 6370 unique, full-length cDNAs from differentiating and adult gonads. Labeled targets from adult gonad, brain, kidney and ‘rest-of-body’ from both sexes were hybridized onto the microarray. Our analyses revealed 1366, 881 and 656 differentially expressed transcripts (34.7% novel) that showed highest expression in ovary, testis and both gonads respectively. Hierarchical clustering showed correlation of the two gonadal transcriptomes and their similarities to those of the brains. In addition, we have identified 276 genes showing sexually dimorphic expression both between the brains and between the gonads. By in situ hybridization, we showed that the gonadal transcripts with the strongest array signal intensities were germline-expressed. We found that five members of the GTP-binding septin gene family, from which only one member (septin 4) has previously been implicated in reproduction in mice, were all strongly expressed in the gonads. Conclusions/Significance We have generated a gonad-derived zebrafish cDNA microarray and demonstrated its usefulness in identifying genes with sexually dimorphic co-expression in both the gonads and the brains. We have also provided the first evidence of large-scale differential gene expression between female and male brains of a teleost. Our microarray would be useful for studying gonad development, differentiation and function not only in zebrafish but also in related teleosts via cross-species hybridizations. Since several genes have been shown to play similar roles in gonadogenesis in zebrafish and other vertebrates, our array may even provide information on genetic disorders affecting gonadal phenotypes and fertility in mammals

    Action Mechanism of Inhibin α-Subunit on the Development of Sertoli Cells and First Wave of Spermatogenesis in Mice

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    Inhibin is an important marker of Sertoli cell (SC) activity in animals with impaired spermatogenesis. However, the precise relationship between inhibin and SC activity is unknown. To investigate this relationship, we partially silenced both the transcription and translation of the gene for the α-subunit of inhibin, Inha, using recombinant pshRNA vectors developed with RNAi-Ready pSIREN-RetroQ-ZsGreen Vector (Clontech Laboratories, Mountain View, Calif). We found that Inha silencing suppresses the cell-cycle regulators Cyclin D1 and Cyclin E and up-regulates the cell-cycle inhibitor P21 (as detected by Western blot analysis), thereby increasing the number of SCs in the G1 phase of the cell cycle and decreasing the amount in the S-phase of the cell cycle (as detected by flow cytometry). Inha silencing also suppressed Pdgfa, Igf1, and Kitl mRNA levels and up-regulated Tgfbrs, Inhba, Inhbb, Cyp11a1, Dhh, and Tjp1 mRNA levels (as indicated by real-time polymerase chain reaction [PCR] analysis). These findings indicate that Inha has the potential to influence the availability of the ligand inhibin and its antagonist activin in the SC in an autocrine manner and inhibit the progression of SC from G1 to S. It may also participate in the development of the blood–testis barrier, Leydig cells, and spermatogenesis through its effect on Dhh, Tjp1, Kitl, and Pdgfa. Real-time PCR and Western blot analyses of Inha, Inhba, and Inhbb mRNA and Inha levels over time show that Inha plays an important role in the formation of round spermatid during the first wave of spermatogenesis in mice

    [Avian cytogenetics goes functional] Third report on chicken genes and chromosomes 2015

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    High-density gridded libraries of large-insert clones using bacterial artificial chromosome (BAC) and other vectors are essential tools for genetic and genomic research in chicken and other avian species... Taken together, these studies demonstrate that applications of large-insert clones and BAC libraries derived from birds are, and will continue to be, effective tools to aid high-throughput and state-of-the-art genomic efforts and the important biological insight that arises from them

    Psychology and legal change: On the limits of a factual jurisprudence.

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    Zen and the Art of Living Mindfully: The Health-Enhancing Potential of Zen Aesthetics

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    Amidst the burgeoning enthusiasm for mindfulness in the West, there is a concern that the largely secular ‘de-contextualized’ way in which it is being harnessed is denuding it of its potential to improve health and well-being. As such, efforts are underway to ‘re-contextualize’ mindfulness, explicitly drawing on the wider framework of Buddhist ideas and practices in which it was initially developed. This paper aims to contribute to this, doing so by focusing on Zen Buddhism, and in particular on Zen aesthetic principles. The article concentrates on the seven principles identified by Hisamatsu (1971) in his classic text Zen and the Fine Arts: kanso (simplicity); fukinsei (asymmetry); koko (austere sublimity); shizen (naturalness); daisuzoku (freedom from routine); sei-jaku (tranquillity); and yūgen (profound grace). The presence of these principles in works of art is seen as reflecting and communicating insights that are central to Buddhism, such as non-attachment. Moreover, these principles do not only apply to the creation and appreciation of art, but have clear applications for treating health-related issues, and improving quality of life more generally. This paper makes the case that embodying these principles in their lives can help people enhance their psychosomatic well-being, and come to a truer understanding of the essence of mindful living

    Fin development in a cartilaginous fish and the origin of vertebrate limbs

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    Recent fossil finds and experimental analysis of chick and mouse embryos highlighted the lateral fin fold theory, which suggests that two pairs of limbs in tetrapods evolved by subdivision of an elongated single fin(1). Here we examine fin development in embryos of the primitive cartilaginous fish, Scyliorhinus canicula (dogfish) using scanning electron microscopy and investigate expression of genes known to be involved in limb positioning, identity and patterning in higher vertebrates. Although we did not detect lateral fin folds in dogfish embryos, Engrailed-1 expression suggests that the body is compartmentalized dorsoventrally. Furthermore, specification of limb identity occurs through the Tbx4 and Tbx5 genes, as in higher vertebrates. In contrast, unlike higher vertebrates, we did not detect Shh transcripts in dogfish fin-buds, although dHand (a gene involved in establishing Shh) is expressed. In S. canicula, the main fin axis seems to lie parallel to the body axis. 'Freeing' fins from the body axis and establishing a separate 'limb' axis has been proposed to be a crucial step in evolution of tetrapod limbs(2,3). We suggest that Shh plays a critical role in this process.</p
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