120 research outputs found

    Genome sequence of the button mushroom Agaricus bisporus reveals mechanisms governing adaptation to a humic-rich ecological niche

    Get PDF
    Agaricus bisporus is the model fungus for the adaptation, persistence, and growth in the humic-rich leaf-litter environment. Aside from its ecological role, A. bisporus has been an important component of the human diet for over 200 y and worldwide cultivation of the "button mushroom" forms a multibillion dollar industry. We present two A. bisporus genomes, their gene repertoires and transcript profiles on compost andduringmushroomformation.The genomes encode a full repertoire of polysaccharide-degrading enzymes similar to that of wood-decayers. Comparative transcriptomics of mycelium grown on defined medium, casing-soil, and compost revealed genes encoding enzymes involved in xylan, cellulose, pectin, and protein degradation aremore highly expressed in compost. The striking expansion of heme-thiolate peroxidases and Ξ²-etherases is distinctive from Agaricomycotina wood-decayers and suggests a broad attack on decaying lignin and related metabolites found in humic acid-rich environment. Similarly, up-regulation of these genes together with a lignolytic manganese peroxidase, multiple copper radical oxidases, and cytochrome P450s is consistent with challenges posed by complex humic-rich substrates. The gene repertoire and expression of hydrolytic enzymes in A. bisporus is substantially different from the taxonomically related ectomycorrhizal symbiont Laccaria bicolor. A common promoter motif was also identified in genes very highly expressed in humic-rich substrates. These observations reveal genetic and enzymatic mechanisms governing adaptation to the humic-rich ecological niche formed during plant degradation, further defining the critical role such fungi contribute to soil structure and carbon sequestration in terrestrial ecosystems. Genome sequence will expedite mushroom breeding for improved agronomic characteristics

    Lrp5 Is Not Required for the Proliferative Response of Osteoblasts to Strain but Regulates Proliferation and Apoptosis in a Cell Autonomous Manner

    Get PDF
    Although Lrp5 is known to be an important contributor to the mechanisms regulating bone mass, its precise role remains unclear. The aim of this study was to establish whether mutations in Lrp5 are associated with differences in the growth and/or apoptosis of osteoblast-like cells and their proliferative response to mechanical strain in vitro. Primary osteoblast-like cells were derived from cortical bone of adult mice lacking functional Lrp5 (Lrp5βˆ’/βˆ’), those heterozygous for the human G171V High Bone Mass (HBM) mutation (LRP5G171V) and their WT littermates (WTLrp5, WTHBM). Osteoblast proliferation over time was significantly higher in cultures of cells from LRP5G171V mice compared to their WTHBM littermates, and lower in Lrp5βˆ’/βˆ’ cells. Cells from female LRP5G171V mice grew more rapidly than those from males, whereas cells from female Lrp5βˆ’/βˆ’ mice grew more slowly than those from males. Apoptosis induced by serum withdrawal was significantly higher in cultures from Lrp5βˆ’/βˆ’ mice than in those from WTHBM or LRP5G171V mice. Exposure to a single short period of dynamic mechanical strain was associated with a significant increase in cell number but this response was unaffected by genotype which also did not change the β€˜threshold’ at which cells responded to strain. In conclusion, the data presented here suggest that Lrp5 loss and gain of function mutations result in cell-autonomous alterations in osteoblast proliferation and apoptosis but do not alter the proliferative response of osteoblasts to mechanical strain in vitro

    Control of Bone Mass and Remodeling by PTH Receptor Signaling in Osteocytes

    Get PDF
    Osteocytes, former osteoblasts buried within bone, are thought to orchestrate skeletal adaptation to mechanical stimuli. However, it remains unknown whether hormones control skeletal homeostasis through actions on osteocytes. Parathyroid hormone (PTH) stimulates bone remodeling and may cause bone loss or bone gain depending on the balance between bone resorption and formation. Herein, we demonstrate that transgenic mice expressing a constitutively active PTH receptor exclusively in osteocytes exhibit increased bone mass and bone remodeling, as well as reduced expression of the osteocyte-derived Wnt antagonist sclerostin, increased Wnt signaling, increased osteoclast and osteoblast number, and decreased osteoblast apoptosis. Deletion of the Wnt co-receptor LDL related receptor 5 (LRP5) attenuates the high bone mass phenotype but not the increase in bone remodeling induced by the transgene. These findings demonstrate that PTH receptor signaling in osteocytes increases bone mass and the rate of bone remodeling through LRP5-dependent and -independent mechanisms, respectively

    Social networks and infant mortality: the impact of bonding and bridging on birth outcomes for women from diverse backgrounds 2010-2013

    No full text
    Qualitative and quantitative data relating to social networks and support received by women from diverse backgrounds during pregnancy and following the birth of their child. Data was collected at two sites from women who experienced an infant death (n=23) and women who had a child over the age of 1 and had felt well supported during the period in question (n=26). Infant mortality among some UK minority ethnic groups and teenage mothers is significantly higher than amongst women in general. This study explores support for maternal and infant health in a range of ethnic and social groups. A new approach will be used to answer the following questions: (1) What is the nature and extent of social networks for maternal and child health In England and how are these shaped by ethnicity, religious identity, social class and gender? (2) What interventions to address barriers to maternal and child health are suggested by women who have experienced an infant mortality and how effectively can these be translated into practice? The study will review current knowledge from existing literature and databases and from policymakers and practitioners. Women from a range of backgrounds in two matched groups will also be interviewed - those who have (i) experienced an infant death (ii) a healthy child after 1 year. Interviews will explore the extent and nature of women's social networks for health and identify gaps in support. Women interviewed will be supported to develop and test solutions that address the problems identified, using methods that model the structural change needed to reduce inequalities in health. </p

    Bone Meniscus Bone Title of the Invention: Composite Bone Implants Abstract Title: A decelluralised implant material

    Get PDF
    A product for use as an implant includes a decellularised natural multi-composite bone transplant material 5. It is decellularised by 90-100% of the cells. The product may be derived from allogeneic or xenogeneic tissue, specifically porcine tissue and may be a ligament, meniscus or enthesis. A method of forming the product is also described and involves freezing and thawing; the use of a fluid jet; incubating in a hypotonic solution with an anionic detergent; washing with hypotonic or isotonic washes; the use of nuclease enzyme and an oxidising agent
    • …
    corecore