54 research outputs found

    Possible new Arkansas endemic plant revealed by DNA sequence analysis, A

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    Cardamine angustata var. ouachitana, a wildflower in the mustard family (Brassicaceae), was described by Smith in 1982 to include a form of Cardamine found only in the Ouachita Mountains of Arkansas. This variety is morphologically very similar to typical Cardamine angustata. The major difference noted by Smith for the two varieties was the complete lack of leaf hairs (trichomes) in the new variety, whereas typical Cardamine angustata normally possesses trichomes. However, Al-Shehbaz rejected the variety ouachitana and reduced it to synonymy with the typical C. angustata. The recommendation of Al-Shehbaz has been followed and the taxon Cardamine angustata var. ouachitana is currently not accepted by most plant taxonomists. We performed a preliminary evaluation of the status of Cardamine angustata var. ouachitana by comparing ribosomal internal transcribed spacer region DNA sequences from specimens of Cardamine angustata var. ouachitana with sequences of Cardamine angustata from the main range of the species and other related species of Cardamine. Phylogenetic analyses of these data produced an unexpected result; specimens of C. angustata var. ouachitana were actually closely related to C. concatenata, rather than the expected close relationship with C. angustata. However, C. angustata var. ouachitana is morphologically distinct from C. concatenata. These results suggest that Cardamine angustata var. ouachitana is actually a new species found only in the Ouachita Mountains of Arkansas

    An international effort towards developing standards for best practices in analysis, interpretation and reporting of clinical genome sequencing results in the CLARITY Challenge

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    BACKGROUND: There is tremendous potential for genome sequencing to improve clinical diagnosis and care once it becomes routinely accessible, but this will require formalizing research methods into clinical best practices in the areas of sequence data generation, analysis, interpretation and reporting. The CLARITY Challenge was designed to spur convergence in methods for diagnosing genetic disease starting from clinical case history and genome sequencing data. DNA samples were obtained from three families with heritable genetic disorders and genomic sequence data was donated by sequencing platform vendors. The challenge was to analyze and interpret these data with the goals of identifying disease causing variants and reporting the findings in a clinically useful format. Participating contestant groups were solicited broadly, and an independent panel of judges evaluated their performance. RESULTS: A total of 30 international groups were engaged. The entries reveal a general convergence of practices on most elements of the analysis and interpretation process. However, even given this commonality of approach, only two groups identified the consensus candidate variants in all disease cases, demonstrating a need for consistent fine-tuning of the generally accepted methods. There was greater diversity of the final clinical report content and in the patient consenting process, demonstrating that these areas require additional exploration and standardization. CONCLUSIONS: The CLARITY Challenge provides a comprehensive assessment of current practices for using genome sequencing to diagnose and report genetic diseases. There is remarkable convergence in bioinformatic techniques, but medical interpretation and reporting are areas that require further development by many groups

    Compromised global embryonic transcriptome associated with advanced maternal age

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    Purpose To investigate the global transcriptome and associated embryonic molecular networks impacted with advanced maternal age (AMA). Methods Blastocysts derived from donor oocyte IVF cycles with no male factor infertility (< 30 years of age) and AMA blastocysts (≥ 42 years) with no other significant female factor infertility or male factor infertility were collected with informed patient consent. RNA sequencing libraries were prepared using the SMARTer® Ultra® Low Kit (Clontech Laboratories) and sequenced on the Illumina HiSEQ 4000. Bioinformatics included Ingenuity® Pathway Analysis (Qiagen) with ViiA™7 qPCR utilized for gene expression validation (Applied Biosystems). Results A total of 2688 significant differentially expressed transcripts were identified to distinguish the AMA blastocysts from young, donor controls. 2551 (95%) of these displayed decreased transcription in the blastocysts from older women. Pathway analysis revealed three altered molecular signaling networks known to be critical for embryo and fetal development: CREBBP, ESR1, and SP1. Validation of genes within these networks confirmed the global decreased transcription observed in AMA blastocysts (P < 0.05). Conclusions A significant, overall decreased global transcriptome was observed in blastocysts from AMA women. The ESR1/SP1/CREBBP pathway, in particular, was found to be a highly significant upstream regulator impacting biological processes that are vital during embryonic patterning and pre-implantation development. These results provide evidence that AMA embryos are compromised on a cell signaling level which can repress the embryo’s ability to proliferate and implant, contributing to a deterioration of reproductive outcomes

    Contemporary genetic technologies and female reproduction

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    BACKGROUNDThe Fifth Evian Annual Reproduction (EVAR) Workshop Meeting discussed knowledge regarding contemporary genetics in female reproduction.METHODSSpecialist reproductive medicine clinicians and geneticists delivered presentations based on published literature and current research. The content of this report is based on the expert presentations and subsequent group discussions that took place during this Workshop.RESULTSNumerous ovarian genes with a role in infertility have been identified. Future challenges for genetic screening of patients, such as those with polycystic ovary syndrome, primary ovarian insufficiency or endometriosis, include the identification of high-throughput strategies and how to apply these findings to infertile patients. The identification of high-quality embryos in IVF using objective technologies remains a high priority in order to facilitate single-embryo transfer. Gene expression profiling of cumulus cells surrounding the oocyte, and proteomic and metabolomic approaches in embryo culture media may significantly improve non-invasive embryo quality assessment.CONCLUSIONSThe way forward in advancing the knowledge of genes involved in reproduction was considered to be through genome-wide association studies involving large numbers of patients. Establishing international collaboration is required to enable the application of such technologies in sufficient numbers of patients

    Early Warnings of the Hazards of Federal Deposit Insurance at the Time of Its Inception

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    Time to raft up

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    Human and mouse embryonic development, metabolism and gene expression are altered by an ammonium gradient in vitro

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    Ammonium is generated in culture media by the spontaneous deamination of amino acids at 37 °C and through the metabolism of amino acids by human embryos. The appearance of ammonium is a time-dependent phenomenon and can compromise embryo physiology, development and viability. In this study, the effects of a gradient of ammonium on the development, metabolism and transcriptome of human and mouse embryos were investigated. Pronucleate oocytes were cultured in the presence of an ammonium gradient that mimicked the spontaneous deamination of Eagle's amino acids together with 1 mM glutamine. All embryos were cultured in sequential media G1/G2 at 5% O2, 6% CO2 and 89% N2. Human embryo metabolism was assessed through a non-invasive fluorometric analysis of pyruvate consumption. Transcriptome analysis was performed on the resultant blastocysts from both species using a microarray technology. Embryo development prior to compaction was negatively affected by the presence of low levels of ammonium in both species. Human embryo metabolism was significantly inhibited after just 24 and 48 h of culture. Transcriptome analysis of blastocysts from both species revealed significantly altered gene expression profiles, both decreased and increased. Functional annotation of the altered genes revealed the following over represented biological processes: metabolism, cell growth and/or maintenance, transcription, cell communication, transport, development and transcription regulation. These data emphasize the enhanced sensitivity of the cleavage-stage embryo to its environment and highlight the requirement to renew culture media at frequent intervals in order to alleviate the in vitro induced effects of ammonium build-up in the environment surrounding the embryo.</jats:p
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