277 research outputs found

    The genome of the green anole lizard and a comparative analysis with birds and mammals

    Full text link
    The evolution of the amniotic egg was one of the great evolutionary innovations in the history of life, freeing vertebrates from an obligatory connection to water and thus permitting the conquest of terrestrial environments1. Among amniotes, genome sequences are available for mammals2 and birds3–5, but not for non-avian reptiles. Here we report the genome sequence of the North American green anole lizard, Anolis carolinensis. We find that A. carolinensis microchromosomes are highly syntenic with chicken microchromosomes, yet do not exhibit the high GC and low repeat content that are characteristic of avian microchromosomes3. Also, A. carolinensis mobile elements are very young and diverse – more so than in any other sequenced amniote genome. This lizard genome’s GC content is also unusual in its homogeneity, unlike the regionally variable GC content found in mammals and birds6. We describe and assign sequence to the previously unknown A. carolinensis X chromosome. Comparative gene analysis shows that amniote egg proteins have evolved significantly more rapidly than other proteins. An anole phylogeny resolves basal branches to illuminate the history of their repeated adaptive radiations

    The genome of the green anole lizard and a comparative analysis with birds and mammals

    Get PDF
    The evolution of the amniotic egg was one of the great evolutionary innovations in the history of life, freeing vertebrates from an obligatory connection to water and thus permitting the conquest of terrestrial environments. Among amniotes, genome sequences are available for mammals and birds, but not for non-avian reptiles. Here we report the genome sequence of the North American green anole lizard, Anolis carolinensis. We find that A. carolinensis microchromosomes are highly syntenic with chicken microchromosomes, yet do not exhibit the high GC and low repeat content that are characteristic of avian microchromosomes. Also, A. carolinensis mobile elements are very young and diverse—more so than in any other sequenced amniote genome. The GC content of this lizard genome is also unusual in its homogeneity, unlike the regionally variable GC content found in mammals and birds. We describe and assign sequence to the previously unknown A. carolinensis X chromosome. Comparative gene analysis shows that amniote egg proteins have evolved significantly more rapidly than other proteins. An anole phylogeny resolves basal branches to illuminate the history of their repeated adaptive radiations.National Science Foundation (U.S.) (NSF grant DEB-0920892)National Science Foundation (U.S.) (NSF grant DEB-0844624)National Human Genome Research Institute (U.S.

    The genome of the green anole lizard and a comparative analysis with birds and mammals

    Get PDF
    The evolution of the amniotic egg was one of the great evolutionary innovations in the history of life, freeing vertebrates from an obligatory connection to water and thus permitting the conquest of terrestrial environments1. Among amniotes, genome sequences are available for mammals2 and birds3–5, but not for non-avian reptiles. Here we report the genome sequence of the North American green anole lizard, Anolis carolinensis. We find that A. carolinensis microchromosomes are highly syntenic with chicken microchromosomes, yet do not exhibit the high GC and low repeat content that are characteristic of avian microchromosomes3. Also, A. carolinensis mobile elements are very young and diverse – more so than in any other sequenced amniote genome. This lizard genome’s GC content is also unusual in its homogeneity, unlike the regionally variable GC content found in mammals and birds6. We describe and assign sequence to the previously unknown A. carolinensis X chromosome. Comparative gene analysis shows that amniote egg proteins have evolved significantly more rapidly than other proteins. An anole phylogeny resolves basal branches to illuminate the history of their repeated adaptive radiations

    FAM20C Overview: Classic and Novel Targets, Pathogenic Variants and Raine Syndrome Phenotypes

    No full text
    FAM20C is a gene coding for a protein kinase that targets S-X-E/pS motifs on different phosphoproteins belonging to diverse tissues. Pathogenic variants of FAM20C are responsible for Raine syndrome (RS), initially described as a lethal and congenital osteosclerotic dysplasia characterized by generalized atherosclerosis with periosteal bone formation, characteristic facial dysmorphisms and intracerebral calcifications. The aim of this review is to give an overview of targets and variants of FAM20C as well as RS aspects. We performed a wide phenotypic review focusing on clinical aspects and differences between all lethal (LRS) and non-lethal (NLRS) reported cases, besides the FAM20C pathogenic variant description for each. As new targets of FAM20C kinase have been identified, we reviewed FAM20C targets and their functions in bone and other tissues, with emphasis on novel targets not previously considered. We found the classic lethal and milder non-lethal phenotypes. The milder phenotype is defined by a large spectrum ranging from osteonecrosis to osteosclerosis with additional congenital defects or intellectual disability in some cases. We discuss our current understanding of FAM20C deficiency, its mechanism in RS through classic FAM20C targets in bone tissue and its potential biological relevance through novel targets in non-bone tissues

    A measurement of ΔΓs\Delta \Gamma_{s}

    No full text
    International audienceUsing a dataset corresponding to 9 fb−19~\mathrm{fb}^{-1} of integrated luminosity collected with the LHCb detector between 2011 and 2018 in proton-proton collisions, the decay-time distributions of the decay modes Bs0→J/ψηâ€ČB_s^0 \rightarrow J/\psi \eta' and Bs0→J/ψπ+π−B_s^0 \rightarrow J/\psi \pi^{+} \pi^{-} are studied. The decay-width difference between the light and heavy mass eigenstates of the Bs0B_s^0 meson is measured to be ΔΓs=0.087±0.012±0.009 ps−1\Delta \Gamma_s = 0.087 \pm 0.012 \pm 0.009 \, \mathrm{ps}^{-1}, where the first uncertainty is statistical and the second systematic

    Study of Bc+→χcπ+B_c^+ \rightarrow \chi_c \pi^+ decays

    No full text
    International audienceA study of Bc+→χcπ+B_c^+ \rightarrow \chi_c \pi^+ decays is reported using proton-proton collision data, collected with the LHCb detector at centre-of-mass energies of 7, 8, and 13 TeV, corresponding to an integrated luminosity of 9fb−1^{-1}. The decay Bc+→χc2π+B_c^+ \rightarrow \chi_{c2} \pi^+ is observed for the first time, with a significance exceeding seven standard deviations. The relative branching fraction with respect to the Bc+→J/ψπ+B_c^+ \rightarrow J/\psi \pi^+ decay is measured to be BBc+→χc2π+BBc+→J/ψπ+=0.37±0.06±0.02±0.01, \frac{\mathcal{B}_{B_c^+ \rightarrow \chi_{c2} \pi^+}} {\mathcal{B}_{B_c^+ \rightarrow J/\psi \pi^+}} = 0.37 \pm 0.06 \pm 0.02 \pm 0.01 , where the first uncertainty is statistical, the second is systematic, and the third is due to the knowledge of the χc→J/ÏˆÎł\chi_c \rightarrow J/\psi \gamma branching fraction. No significant Bc+→χc1π+B_c^+ \rightarrow \chi_{c1} \pi^+ signal is observed and an upper limit for the relative branching fraction for the Bc+→χc1π+B_c^+ \rightarrow \chi_{c1} \pi^+ and Bc+→χc2π+B_c^+ \rightarrow \chi_{c2} \pi^+ decays of BBc+→χc1π+BBc+→χc2π+<0.49 \frac{\mathcal{B}_{B_c^+ \rightarrow \chi_{c1} \pi^+}} {\mathcal{B}_{B_c^+ \rightarrow \chi_{c2} \pi^+}} < 0.49 is set at the 90% confidence level

    Enhanced production of Λb0\Lambda_b^0 baryons in high-multiplicity pppp collisions at s\sqrt{s} = 13TeV

    No full text
    The production rate of Λb0\Lambda_{b}^{0} baryons relative to B0B^{0} mesons in pppp collisions at a center-of-mass energy s=13\sqrt{s} = 13 TeV is measured by the LHCb experiment. The ratio of Λb0\Lambda_{b}^{0} to B0B^{0} production cross-sections shows a significant dependence on both the transverse momentum and the measured charged-particle multiplicity. At low multiplicity, the ratio measured at LHCb is consistent with the value measured in e+e−e^{+}e^{-} collisions, and increases by a factor of ∌2\sim2 with increasing multiplicity. At relatively low transverse momentum, the ratio of Λb0\Lambda_{b}^{0} to B0B^{0} cross-sections is higher than what is measured in e+e−e^{+}e^{-} collisions, but converges with the e+e−e^{+}e^{-} ratio as the momentum increases. These results imply that the evolution of heavy bb quarks into final-state hadrons is influenced by the density of the hadronic environment produced in the collision. Comparisons with a statistical hadronization model and implications for the mechanisms enforcing quark confinement are discussed.The production rate of Λb0\Lambda_{b}^{0} baryons relative to B0B^{0} mesons in pppp collisions at a center-of-mass energy s=13\sqrt{s} = 13 TeV is measured by the LHCb experiment. The ratio of Λb0\Lambda_{b}^{0} to B0B^{0} production cross-sections shows a significant dependence on both the transverse momentum and the measured charged-particle multiplicity. At low multiplicity, the ratio measured at LHCb is consistent with the value measured in e+e−e^{+}e^{-} collisions, and increases by a factor of ∌2\sim2 with increasing multiplicity. At relatively low transverse momentum, the ratio of Λb0\Lambda_{b}^{0} to B0B^{0} cross-sections is higher than what is measured in e+e−e^{+}e^{-} collisions, but converges with the e+e−e^{+}e^{-} ratio as the momentum increases. These results imply that the evolution of heavy bb quarks into final-state hadrons is influenced by the density of the hadronic environment produced in the collision. Comparisons with a statistical hadronization model and implications for the mechanisms enforcing quark confinement are discussed

    Modification of χc1\chi_{c1}(3872) and ψ\psi(2SS) production in ppPb collisions at sNN=8.16\sqrt{s_{NN}} = 8.16 TeV

    No full text
    International audienceThe LHCb collaboration measures production of the exotic hadron χc1\chi_{c1}(3872) in proton-nucleus collisions for the first time. Comparison with the charmonium state ψ\psi(2SS) suggests that the exotic χc1\chi_{c1}(3872) experiences different dynamics in the nuclear medium than conventional hadrons, and comparison with data from proton-proton collisions indicates that the presence of the nucleus may modify χc1\chi_{c1}(3872) production rates. This is the first measurement of the nuclear modification factor of an exotic hadron

    Measurements of the branching fraction ratio B(ϕ→Ό+Ό−)/B(ϕ→e+e−)\cal{B}(\phi \to \mu^+\mu^-)/\cal{B}(\phi \to e^+e^-) with charm meson decays

    No full text
    International audienceMeasurements of the branching fraction ratio B(ϕ→Ό+Ό−)/B(ϕ→e+e−){\cal{B}(\phi \to \mu^+ \mu^-)/\cal{B}(\phi\to e^+e^-)} with Ds+→π+ϕ{D_{s}^{+} \to \pi^{+} \phi} and D+→π+ϕ{D^{+} \to \pi^{+} \phi} decays, denoted RϕπsR^{s}_{\phi \pi} and RϕπdR^{d}_{\phi \pi}, are presented. The analysis is performed using a dataset corresponding to an integrated luminosity of 5.4 fb−1\,\rm{fb}^{-1} of pppp collision data collected with the LHCb experiment. The branching fractions are normalised with respect to the B+→K+J/ψ(→e+e−){B^{+} \to K^{+} J/\psi(\to e^+e^-)} and B+→K+J/ψ(→Ό+Ό−){B^{+} \to K^{+} J/\psi(\to \mu^+\mu^-)} decay modes. The combination of the results yields Rϕπ=1.022±0.012 (stat) ±0.048 (syst). R_{\phi \pi} = 1.022 \pm 0.012 \,({\rm stat}) \, \pm 0.048 \,({\rm syst}). The result is compatible with previous measurements of the ϕ→ℓ+ℓ−\phi \to \ell^{+}\ell^{-} branching fractions and predictions based on the Standard Model

    Determination of short- and long-distance contributions in B0→K∗0ÎŒ+Ό−B^{0}\to K^{*0}\mu^+\mu^- decays

    No full text
    International audienceAn amplitude analysis of the B0→K∗0ÎŒ+Ό−B^0 \to K^{*0} \mu^+\mu^- decay is presented. The analysis is based on data collected by the LHCb experiment from proton-proton collisions at s=7, 8\sqrt{s} = 7,\,8 and 1313 TeV, corresponding to an integrated luminosity of 4.74.7 fb−1^{-1}. For the first time, Wilson coefficients and non-local hadronic contributions are accessed directly from the unbinned data, where the latter are parameterised as a function of q2q^2 with a polynomial expansion. Wilson coefficients and non-local hadronic parameters are determined under two alternative hypotheses: the first relies on experimental information alone, while the second one includes information from theoretical predictions for the non-local contributions. Both models obtain similar results for the parameters of interest. The overall level of compatibility with the Standard Model is evaluated to be between 1.8 and 1.9 standard deviations when looking at the C9\mathcal{C}_9 Wilson coefficient alone, and between 1.3 and 1.4 standard deviations when considering the full set of C9, C10, C9â€Č\mathcal{C}_9, \, \mathcal{C}_{10}, \, \mathcal{C}_9^\prime and C10â€Č\mathcal{C}_{10}^\prime Wilson coefficients. The ranges reflect the theoretical assumptions made in the analysis
    • 

    corecore