268 research outputs found

    A microRNA (mmu-miR-124) prevents Sox9 expression in developing mouse ovarian cells

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    In mammals, sex differentiation depends on gonad development, which is controlled by two groups of sex-determining genes that promote one gonadal sex and antagonize the opposite one. SOX9 plays a key role during testis development in all studied vertebrates, whereas it is kept inactive in the XX gonad at the critical time of sex determination, otherwise, ovary-to-testis gonadal sex reversal occurs. However, molecular mechanisms underlying repression of Sox9 at the beginning of ovarian development, as well as other important aspects of gonad organogenesis, remain largely unknown. Because there is indirect evidence that micro-RNAs (miRNA) are necessary for testicular function, the possible involvement of miRNAs in mammalian sex determination deserved further research. Using microarray technology, we have identified 22 miRNAs showing sex-specific expression in the developing gonads during the critical period of sex determination. Bioinformatics analyses led to the identification of miR-124 as the candidate gene for ovarian development. We knocked down or overexpressed miR-124 in primary gonadal cell cultures and observed that miR-124 is sufficient to induce the repression of both SOX9 translation and transcription in ovarian cells. Our results provide the first evidence of the involvement of a miRNA in the regulation of the gene controlling gonad development and sex determination. The miRNA microarray data reported here will help promote further research in this field, to unravel the role of other miRNAs in the genetic control of mammalian sex determination

    Smart Power Monitoring System on Solar

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    The design and development of a Smart Power monitoring device has reported in this paper. System has been designed that can be used to monitor electrical appliances such as voltage, current and power of solar panel. The system consists of a smart sensing unit that detects and controls the energy deliver and it used for daily activities by following different tariff rates. A developed prototype has been extensively tested and experimental results have compared with conventional measuring devices. This work has been designed to implement smart power monitoring and control system through IOT using cloud data storage.In this system we are collecting the energy data from the solar panel and pass it to the microcontroller device. The device will pass this collected data via RS232 to the GSM sender.Here two GSM devices are used, that is sender and receiver.The PHP will perform some operation on the received data and stored it in database

    Normal Levels of Sox9 Expression in the Developing Mouse Testis Depend on the TES/TESCO Enhancer, but This Does Not Act Alone

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    During mouse sex determination, transient expression of the Y-linked gene Sry up-regulates its direct target gene Sox9, via a 3.2 kb testis specific enhancer of Sox9 (TES), which includes a core 1.4 kb element, TESCO. SOX9 activity leads to differentiation of Sertoli cells, rather than granulosa cells from the bipotential supporting cell precursor lineage. Here, we present functional analysis of TES/TESCO, using CRISPR/Cas9 genome editing in mice. Deletion of TESCO or TES reduced Sox9 expression levels in XY fetal gonads to 60 or 45% respectively relative to wild type gonads, and reduced expression of the SOX9 target Amh. Although human patients heterozygous for null mutations in SOX9, which are assumed to have 50% of normal expression, often show XY female sex reversal, mice deleted for one copy of Sox9 do not. Consistent with this, we did not observe sex reversal in either TESCO-/- or TES-/- XY embryos or adult mice. However, embryos carrying both a conditional Sox9 null allele and the TES deletion developed ovotestes. Quantitative analysis of these revealed levels of 23% expression of Sox9 compared to wild type, and a significant increase in the expression of the granulosa cell marker Foxl2. This indicates that the threshold in mice where sex reversal begins to be seen is about half that of the ~50% levels predicted in humans. Our results demonstrate that TES/TESCO is a crucial enhancer regulating Sox9 expression in the gonad, but point to the existence of additional enhancers that act redundantly

    Guidelines for the use of cell lines in biomedical research

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    Cell-line misidentification and contamination with microorganisms, such as mycoplasma, together with instability, both genetic and phenotypic, are among the problems that continue to affect cell culture. Many of these problems are avoidable with the necessary foresight, and these Guidelines have been prepared to provide those new to the field and others engaged in teaching and instruction with the information necessary to increase their awareness of the problems and to enable them to deal with them effectively. The Guidelines cover areas such as development, acquisition, authentication, cryopreservation, transfer of cell lines between laboratories, microbial contamination, characterisation, instability and misidentification. Advice is also given on complying with current legal and ethical requirements when deriving cell lines from human and animal tissues, the selection and maintenance of equipment and how to deal with problems that may arise

    Neuronal migration and ventral subtype identity in the telencephalon depend on SOX1

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    Little is known about the molecular mechanisms and intrinsic factors that are responsible for the emergence of neuronal subtype identity. Several transcription factors that are expressed mainly in precursors of the ventral telencephalon have been shown to control neuronal specification, but it has been unclear whether subtype identity is also specified in these precursors, or if this happens in postmitotic neurons, and whether it involves the same or different factors. SOX1, an HMG box transcription factor, is expressed widely in neural precursors along with the two other SOXB1 subfamily members, SOX2 and SOX3, and all three have been implicated in neurogenesis. SOX1 is also uniquely expressed at a high level in the majority of telencephalic neurons that constitute the ventral striatum (VS). These neurons are missing in Sox1-null mutant mice. In the present study, we have addressed the requirement for SOX1 at a cellular level, revealing both the nature and timing of the defect. By generating a novel Sox1-null allele expressing Ī²-galactosidase, we found that the VS precursors and their early neuronal differentiation are unaffected in the absence of SOX1, but the prospective neurons fail to migrate to their appropriate position. Furthermore, the migration of non-Sox1-expressing VS neurons (such as those expressing Pax6) was also affected in the absence of SOX1, suggesting that Sox1-expressing neurons play a role in structuring the area of the VS. To test whether SOX1 is required in postmitotic cells for the emergence of VS neuronal identity, we generated mice in which Sox1 expression was directed to all ventral telencephalic precursors, but to only a very few VS neurons. These mice again lacked most of the VS, indicating that SOX1 expression in precursors is not sufficient for VS development. Conversely, the few neurons in which Sox1 expression was maintained were able to migrate to the VS. In conclusion, Sox1 expression in precursors is not sufficient for VS neuronal identity and migration, but this is accomplished in postmitotic cells, which require the continued presence of SOX1. Our data also suggest that other SOXB1 members showing expression in specific neuronal populations are likely to play continuous roles from the establishment of precursors to their final differentiation

    Transductionā€Specific ATLAS Reveals a Cohort of Highly Active L 1 Retrotransposons in Human Populations

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    L ong IN terspersed E lementā€1 ( LINE ā€1 or L 1) retrotransposons are the only autonomously active transposable elements in the human genome. The average human genome contains āˆ¼80ā€“100 active L1s, but only a subset of these L1s are highly active or ā€˜hotā€™. Human L1s are closely related in sequence, making it difficult to decipher progenitor/offspring relationships using traditional phylogenetic methods. However, L1 m RNA s can sometimes bypass their own polyadenylation signal and instead utilize fortuitous polyadenylation signals in 3ā€² flanking genomic DNA . Retrotransposition of the resultant m RNA s then results in lineage specific sequence ā€œtagsā€ (i.e., 3ā€² transductions) that mark the descendants of active L1 progenitors. Here, we developed a method (Transductionā€Specific Amplification Typing of L1 Active Subfamilies or TS ā€ ATLAS ) that exploits L1 3ā€² transductions to identify active L1 lineages in a genomeā€wide context. TS ā€ ATLAS enabled the characterization of a putative active progenitor of one L1 lineage that includes the disease causing L1 insertion L1 RP , and the identification of new retrotransposition events within two other ā€œhotā€ L1 lineages. Intriguingly, the analysis of the newly discovered transduction lineage members suggests that L1 polyadenylation, even within a lineage, is highly stochastic. Thus, TS ā€ ATLAS provides a new tool to explore the dynamics of L1 lineage evolution and retrotransposon biology. Long INterspersed Elementā€1 (L1) retrotransposons are the only independently mobile elements in the human genome. We developed Transductionā€Specific Amplification Typing of L1 Active Subfamilies (TSā€ATLAS), which utilizes L1ā€transduced genomic sequences, to identify a subset of highly active L1s genomeā€wide. TSā€ATLAS enabled the characterization of the putative progenitor of an active diseaseā€causing L1 lineage, and identified new retrotransposition events within two other ā€œhotā€ L1 lineages.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/98809/1/humu22327.pdfhttp://deepblue.lib.umich.edu/bitstream/2027.42/98809/2/humu22327-sup-0001-si.pd

    LINE-1 Retrotransposition Activity in Human Genomes

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    SummaryHighly active (i.e., ā€œhotā€) long interspersed element-1 (LINE-1 or L1) sequences comprise the bulk of retrotransposition activity in the human genome; however, the abundance of hot L1s in the human population remains largely unexplored. Here, we used a fosmid-based, paired-end DNA sequencing strategy to identify 68 full-length L1s that are differentially present among individuals but are absent from the human genome reference sequence. The majority of these L1s were highly active in a cultured cell retrotransposition assay. Genotyping 26 elements revealed that two L1s are only found in Africa and that two more are absent from the H952 subset of the Human Genome Diversity Panel. Therefore, these results suggest that hot L1s are more abundant in the human population than previously appreciated, and that ongoing L1 retrotransposition continues to be a major source of interindividual genetic variation

    Harmless? A hierarchical analysis of poppers use correlates among young gay and bisexual men

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    Ā© 2019 Australasian Professional Society on Alcohol and other Drugs Introduction and Aims: Poppers (alkyl nitrites) are recreational substances commonly used during sexual activity. The current legal status of poppers is complex and wide-ranging bans are increasingly under discussion. Research has identified disproportionate levels of poppers use in sexual minority men. While research on poppers use among sexual minority men exists, little is known about poppers use patterns and correlations with psychosocial and other factors among gay and bisexual young men. Design and Methods: A cross-sectional survey was conducted with 836 Australian gay and bisexual young men aged 18 to 35 years. Descriptive statistics and hierarchical segmentation analyses were conducted to identify poppers use patterns, and correlates of recent poppers use (past 3 months) with personal characteristics, use of other substances, as well as mental and psychosocial health including minority stress, LGBT-community connectedness and participation. Results: High levels of lifetime (38%, n = 315) and recent (24%, n = 204) poppers use were reported. However, few participants reported dependency symptoms, risky consumption or problems arising from using poppers. The final model included three variables (visiting sex-on-premises venues, licensed LGBT venues, and using other substances) and predicted 85% (n = 174) of recent poppers use. No correlations with other concepts or characteristics could be identified. Conclusion: This analysis further supports the hypothesis that poppers may be substances with a comparably low-risk profile. A regulation of poppers with a harm reduction approach may present a valuable public health intervention
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