2,047 research outputs found

    Developing a platform of environmental omics for the green-lipped mussel Perna viridis

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    Session Track: Aquatic and terrestrial ecotoxicologyOral presentationConference Theme: Science across bridges, borders and boundariesThe green-lipped mussel Perna viridis is an important marine biomonitor species in pollution monitoring and ecotoxicological studies in Asia-Pacific region, and considered as a subtropical equivalent biomonitor of the temperate Mytilus species. However, the genomic information of P. viridis is still largely unexplored when compared with Mytilus species. This study aimed to establish a transcriptomic profile of P. viridis using the next generation sequencing technology and provide a good representative set of genomic information for elucidation of toxic mechanisms upon pollution stresses and identification of a suite of suitable biomarkers for monitoring marine pollution and environmental stresses. To obtain a wide spectrum of environmental-associated transcripts, adult mussels (4-5 cm shell length) were collected from different locations in Hong Kong and from those after 24-hour exposures to various challenges of physical stresses and chemical pollutants, so as to cover a wide range of stress-associated transcription patterns for future environmental studies. Two males and females from each location and from each treatment were chosen for obtaining the three target tissues (i.e., hepatopancreas, gill and adductor muscle). For each sex and each tissue type, a total RNA sample was extracted from pooled tissues from the field and laboratory treated mussels. The RNA sample was subjected to cDNA library construction, followed by the RNA-sequencing using a Solexa GAIIx (Illumina). Including the splicing variants, a de novo assembly of a total length of 295,064,579 base-pair (bp) contig was obtained, with 233,257 contigs assembled of an average size of 1264 bp. The 192,879 non-redundant assembled transcripts were blasted against the NCBI nr database and three molluscan EST databases, and resulted in 44,713 transcripts with at least a blast hit, and having a top match with the sequences from the Pacific oyster, Crassostrea gigas (27,651 transcripts). A total of 5,131 transcripts were assigned with KEGG annotation involving in 329 pathways. Based on multivariate statistical analysis, expression patterns of genes from stress associated responses and detoxification were strongly tissue-specific but the differences between genders were little. The anticipated genomic database generated from this study will further strengthen the role of P. viridis as a universal marine biomonitor in the Asia-Pacific region.published_or_final_versio

    De novo transcriptome analysis of Perna viridis highlights tissue-specific patterns for environmental studies

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    Return to fertility after extended chemical castration with a GnRH antagonist

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    BACKGROUND: Antagonistic analogues of GnRH for the treatment of prostate cancer may be used clinically in persons for whom return to fertility after such treatment is important or desirable. The purpose of this study was, therefore, to evaluate the effects of a long term treatment with orntide, a GnRH antagonist, on testosterone levels and fertility in male rats. METHODS: Two groups of male rats received either 120-day orntide microspheres (8.8 mg orntide/kg/120 days) or vehicle alone (control group). Serum orntide and testosterone levels in both groups were monitored at certain intervals for 9 months from the initiation of treatment. After recovery of normal serum testosterone levels in the treated animals, each rat was housed with two proven breeder, but drug-naive, females. RESULTS: All mates of treated rats achieved pregnancy as rapidly as the mates of control rats although two of the control rats did not sire a litter with either female and one sired only one litter. The mean size of the litters of treated (12.3 offspring per litter) and control (10.6 offspring per litter) were similar. All offspring were grossly normal morphologically and behaviorally during the time to weaning. CONCLUSIONS: These results suggest that lack of fertility due to testosterone suppression is reversible after cessation of treatment with this GnRH antagonist

    De novo transcriptome analysis for mechanistic study of organotin-mediated endocrine disruption in Reishia Clavigera

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    Poster presentation: P-63Human ImpactsMany endocrine disrupting compounds are bioaccumulative and toxic to a wide range of marine organisms, leading to reproductive impairment, development of cancer and abnormal metabolism. For instance, organotin compounds (OTs) such as tributyltin and triphenyltin can induce the development of imposex (i.e., superimposition of male sexual organs) in females of over 200 gastropod species. OTs have been widely used as biocides in antifouling paints and industrial applications. Thus they have been released into the marine environment, posing risks to non-target marine organisms and human health. Although many studies have been conducted to ...postprin

    A novel DSPP mutation causes dentinogenesis imperfecta type II in a large Mongolian family

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    <p>Abstract</p> <p>Background</p> <p>Several studies have shown that the clinical phenotypes of dentinogenesis imperfecta type II (DGI-II) may be caused by mutations in <it>dentin sialophosphoprotein </it>(<it>DSPP</it>). However, no previous studies have documented the clinical phenotype and genetic basis of DGI-II in a Mongolian family from China.</p> <p>Methods</p> <p>We identified a large five-generation Mongolian family from China with DGI-II, comprising 64 living family members of whom 22 were affected. Linkage analysis of five polymorphic markers flanking <it>DSPP </it>gene was used to genotype the families and to construct the haplotypes of these families. All five DSPP exons including the intron-exon boundaries were PCR-amplified and sequenced in 48 members of this large family.</p> <p>Results</p> <p>All affected individuals showed discoloration and severe attrition of their teeth, with obliterated pulp chambers and without progressive high frequency hearing loss or skeletal abnormalities. No recombination was found at five polymorphic markers flanking DSPP in the family. Direct DNA sequencing identified a novel A→G transition mutation adjacent to the donor splicing site within intron 3 in all affected individuals but not in the unaffected family members and 50 unrelated Mongolian individuals.</p> <p>Conclusion</p> <p>This study identified a novel mutation (IVS3+3A→G) in <it>DSPP</it>, which caused DGI-II in a large Mongolian family. This expands the spectrum of mutations leading to DGI-II.</p

    MRI of Auto-Transplantation of Bone Marrow-Derived Stem-Progenitor Cells for Potential Repair of Injured Arteries

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    This study was to validate the feasibility of using clinical 3.0T MRI to monitor the migration of autotransplanted bone marrow (BM)-derived stem-progenitor cells (SPC) to the injured arteries of near-human sized swine for potential cell-based arterial repair.The study was divided into two phases. For in vitro evaluation, BM cells were extracted from the iliac crests of 13 domestic pigs and then labeled with a T2 contrast agent, Feridex, and/or a fluorescent tissue marker, PKH26. The viability, the proliferation efficiency and the efficacies of Feridex and/or PKH26 labeling were determined. For in vivo validation, the 13 pigs underwent endovascular balloon-mediated intimal damages of the iliofemoral arteries. The labeled or un-labeled BM cells were autotransplanted back to the same pig from which the BM cells were extracted. Approximately three weeks post-cell transplantation, 3.0T T2-weighted MRI was performed to detect Feridex-created signal voids of the transplanted BM cells in the injured iliofemoral arteries, which was confirmed by subsequent histologic correlation.Of the in vitro study, the viability of dual-labeled BM cells was 95-98%. The proliferation efficiencies of dual-labeled BM cells were not significantly different compared to those of non-labeled cells. The efficacies of Feridex- and PKH26 labeling were 90% and 100%, respectively. Of the in vivo study, 3.0T MRI detected the auto-transplanted BM cells migrated to the injured arteries, which was confirmed by histologic examinations.This study demonstrates the capability of using clinical 3.0T MRI to monitor the auto-transplantation of BM cells that migrate to the injured arteries of large animals, which may provide a useful MRI technique to monitor cell-based arterial repair

    An effective all-atom potential for proteins

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    We describe and test an implicit solvent all-atom potential for simulations of protein folding and aggregation. The potential is developed through studies of structural and thermodynamic properties of 17 peptides with diverse secondary structure. Results obtained using the final form of the potential are presented for all these peptides. The same model, with unchanged parameters, is furthermore applied to a heterodimeric coiled-coil system, a mixed alpha/beta protein and a three-helix-bundle protein, with very good results. The computational efficiency of the potential makes it possible to investigate the free-energy landscape of these 49--67-residue systems with high statistical accuracy, using only modest computational resources by today's standards
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