19 research outputs found

    Genomic evolution and polymorphism: Segmental duplications and haplotypes at 108 regions on 21 chromosomes

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    We describe here extensive, previously unknown, genomic polymorphism in 120 regions, covering 19 autosomes and both sex chromosomes. Each contains duplication within multigene clusters. Of these, 108 are extremely polymorphic with multiple haplotypes.We used the genomic matching technique (GMT), previously used to characterise the major histocompatibility complex (MHC) and regulators of complement activation (RCA).This genome-wide extension of this technique enables the examination of many underlying cis, trans and epistatic interactions responsible for phenotypic differences especially in relation to individuality, evolution and disease susceptibility.The extent of the diversity could not have been predicted and suggests a new model of primate evolution based on conservation of polymorphism rather than de novo mutation

    Formation of a galaxy with a central black hole in the Lemaitre-Tolman model

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    We construct two models of the formation a galaxy with a central black hole, starting from a small initial fluctuation at recombination. This is an application of previously developed methods to find a Lemaitre-Tolman model that evolves from a given initial density or velocity profile to a given final density profile. We show that the black hole itself could be either a collapsed object, or a non-vacuum generalisation of a full Schwarzschild-Kruskal-Szekeres wormhole. Particular attention is paid to the black hole's apparent and event horizons.Comment: REVTeX, 22 pages including 11 figures (25 figure files). Replacement has minor changes in response to the referee, and editorial corrections. To appear in PR

    Quasars and their host galaxies

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    This review attempts to describe developments in the fields of quasar and quasar host galaxies in the past five. In this time period, the Sloan and 2dF quasar surveys have added several tens of thousands of quasars, with Sloan quasars being found to z>6. Obscured, or partially obscured quasars have begun to be found in significant numbers. Black hole mass estimates for quasars, and our confidence in them, have improved significantly, allowing a start on relating quasar properties such as radio jet power to fundamental parameters of the quasar such as black hole mass and accretion rate. Quasar host galaxy studies have allowed us to find and characterize the host galaxies of quasars to z>2. Despite these developments, many questions remain unresolved, in particular the origin of the close relationship between black hole mass and galaxy bulge mass/velocity dispersion seen in local galaxies.Comment: Review article, to appear in Astrophysics Update

    Dimethyl fumarate in patients admitted to hospital with COVID-19 (RECOVERY): a randomised, controlled, open-label, platform trial

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    Dimethyl fumarate (DMF) inhibits inflammasome-mediated inflammation and has been proposed as a treatment for patients hospitalised with COVID-19. This randomised, controlled, open-label platform trial (Randomised Evaluation of COVID-19 Therapy [RECOVERY]), is assessing multiple treatments in patients hospitalised for COVID-19 (NCT04381936, ISRCTN50189673). In this assessment of DMF performed at 27 UK hospitals, adults were randomly allocated (1:1) to either usual standard of care alone or usual standard of care plus DMF. The primary outcome was clinical status on day 5 measured on a seven-point ordinal scale. Secondary outcomes were time to sustained improvement in clinical status, time to discharge, day 5 peripheral blood oxygenation, day 5 C-reactive protein, and improvement in day 10 clinical status. Between 2 March 2021 and 18 November 2021, 713 patients were enroled in the DMF evaluation, of whom 356 were randomly allocated to receive usual care plus DMF, and 357 to usual care alone. 95% of patients received corticosteroids as part of routine care. There was no evidence of a beneficial effect of DMF on clinical status at day 5 (common odds ratio of unfavourable outcome 1.12; 95% CI 0.86-1.47; p = 0.40). There was no significant effect of DMF on any secondary outcome

    Almost total protection from age-related macular degeneration by haplotypes of the Regulators of Complement Activation

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    Age-related macular degeneration (AMD) is the leading cause of blindness in developed countries. It has been proposed that the polymorphism encoding Y402H (T1277C) in the complement factor H gene (CFH) is one of the main determinants of disease. We genotyped the polymorphism at a number of loci in the region encompassing the Regulators of Complement Activation (RCA) on chromosome 1, including T1277C SNP, in 187 patients and 146 controls. Haplotypes have been classified as protective (P) or susceptible (S) with respect to AMD. This included the identification of an S haplotype with a T at 1277. The results show that no single locus should be assumed to be directly responsible for AMD, but rather argue for the existence of RCA haplotypes, which can be assigned meaningful predictive values for AMD. We conclude that the critical sequences are within a region 450. kb centromeric to 128. kb telomeric of CFH

    Mannose binding lectin (MBL) copy number polymorphism in Zebrafish (D. rerio) and identification of haplotypes resistant to L. anguillarum

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    We describe a novel extension of the Genomic Matching Technique (GMT) that defines haplotypes of the mannose binding lectin (MBL) region in Zebrafish (D. rerio). Four ancestral haplotypes have been identified to date, with at least one of these demonstrating a significant increase in resistance to L. anguillarum. MBL activates the lectin pathway of the complement system and stimulates the development of the complement cascade and the Membrane Attack Complex. Polymorphisms in humans have been associated with increased susceptibility and severity to a number of pathogenic organisms. As teleosts have a relatively immature acquired immune system, polymorphisms within MBL and other innate defence genes are likely to be critical in defining their susceptibility/resistance to various pathogenic organisms. We report multiple copies of MBL-like genes in D. rerio, with up to three copies tightly linked within a cluster spanning ∼15 kb on chromosome 2. Genomic analysis suggests that duplication, retroviral insertion and possibly gene mutation and/or deletion have been key factors in the evolution of this cluster. Molecular analysis has revealed extensive polymorphism, including at least five distinct amplicons and haplospecific gene copy number variation. This study demonstrates polymorphism within a critical component of the teleost innate immune system. The polymorphisms and the haplotypes encoding the unique variants are likely to be informative in defining susceptibility/resistance to infectious agents commonly encountered within aquatic environments. Future investigations will define other important haplotypes and transfer the knowledge to other finfish species, thereby enabling selection of broodstock for the aquaculture industry

    Evaluation of the class II region of the major histocompatibility complex of the greyhound with the genomic matching technique and sequence-based typing

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    The class II region of the major histocompatibility complex was evaluated in 25 greyhounds by sequence-based typing and the genomic matching technique (GMT). Two new DLA-DRB1 alleles were identified. Twenty-four dogs carried the DLA-DRB1*01201/DQA1*00401/DQB1*01303/DQB1*01701 haplotype, which carries two DQB1 alleles. One haplotype was identified from which DQB1 and DQA1 appeared to be deleted. The GMT enabled detection of DQB1 copy number, discrimination of the different class II haplotypes and the identification of new, possibly biologically relevant polymorphisms

    Novel sequence elements define ancestral haplotypes of the region encompassing complement factor H

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    The genomic region encompassing complement factor H (CFH) is thought to be important in determining susceptibility to inflammatory diseases such as age-related macular degeneration, but only limited polymorphism has been described. After applying the genomic matching technique to three-generation families and an ethnically diverse reference panel we have demonstrated that the polymorphism resembles that found in the major histocompatibility complex. The different ancestral haplotypes carry either T or C at T1277C but also other more polymorphic alleles over a region of 2 Mb. Thus the association between age-related macular degeneration and T1277 or Y402 actually reflects multiple linked polymorphisms including an indel that cannot be dissected from any direct effect of Y402 and may be more important. We show for the first time that simple algorithms can identify genomic sequence elements that appear to be more useful haplospecific markers than single nucleotide polymorphism or microsatellites
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