Complete Nucleotide Sequence and Full-Length cDNA Clone of S.A.AR86, a South African Alphavirus Related to Sindbis

S.A.AR86 and Girdwood S.A., two South African Sindbis-like arboviruses, are closely related antigenically to the Swedish isolate, Ockelbo82 [Lundström, J. O., Vene, S., Saluzzo, J. F., and Niklasson, B. (1993) Am. J. Trop. Med. Hyg. 49(5), 531-537]. Each of these viruses is associated with human disease, and Girdwood S.A. was isolated from a human case. In addition, S.A.AR86 is unique among Sindbis-like viruses in that adult mice remain sensitive to lethal infection with S.A.AR86. The complete genomic sequences of S.A.AR86 and Girdwood S.A. were determined. The S.A.AR86 RNA genome contained 11,663 nucleotides, excluding the 5' CAP structure and 3' poly(A) tail. In comparison to the consensus sequence of the prototype Egyptian Sindbis strain AR339, S.A.AR86 differed at 5.57% of the nucleotides, including a 54-nucleotide deletion, two insertions of 6 nucleotides each, and a 3-nucleotide insertion in the 3' terminal one-third of the S.A.AR86 nsP3 gene. S.A.AR86 is one of only three alphaviruses sequenced to date that does not have an opal termination codon between the nsP3 and the nsP4 genes. These genes are separated by a cysteine codon in the S.A.AR86 genome. The genome of Girdwood S.A. was 11,717 nucleotides in length, excluding the 5' CAP and 3' poly(A) tail. Girdwood S.A. contained an opal termination codon between nsP3 and nsP4 and did not have the large 54-nucleotide deletion in nsP3, although Girdwood S.A. did contain the remaining insertions and deletions characteristic of S.A.AR86. S.A.AR86 was more closely related to Girdwood S.A. than to the Egyptian isolate, and the South African isolates as a group were more closely related to the Swedish isolate. Comparison of the S.A.AR86 sequence to that of Ockelbo82, Girdwood S.A., and Sindbis virus AR339 revealed several codons where S.A.AR86 differed from the conserved amino acid encoded by the other three viruses. These changes may be related to the ability of S.A.AR86 to initiate a lethal central nervous system infection in adult mice. To fulfill a prerequisite for testing this hypothesis, a full-length cDNA clone of S.A.AR86 was constructed from which infectious genomic RNA replicas could be derived. The sequence of this clone differed from the S.A.AR86 genomic RNA sequence at four translationally silent positions, and virus derived from the clone reproduced the adult mouse neurovirulence phenotype of its biological progenitor

Deduced consensus sequence of Sindbis virus strain AR339: mutations contained in laboratory strains which affect cell culture and in vivo phenotypes.

The consensus sequence of the Sindbis virus AR339 isolate, the prototype alphavirus, has been deduced. THe results presented here suggest (i) that a substantial proportion of the sequence divergence evident between the consensus sequence and sequences of laboratory strains of AR339 has resulted from selection for efficient growth in cell culture, (ii) that many of these changes affect the virulence of the virus in animal models, and (iii) that such modified genetic backgrounds present in laboratory strains can exert a significant influence on genetic studies of virus pathogenesis and host range. A laboratory strain of Sindbis virus AR339 was sequenced and cloned as a cDNA (pTRSB) from which infectious virus (TRSB) could be derived. The consensus sequence was deduced from the complete sequences of pTRSB and HRsp (E. G. Strauss, C. M. Rice, and J. H. Strauss, Virology 133:92-110, 1984), from partial sequences of the glycoprotein genes of three other AR339 laboratory strains, and by comparison with the sequences of the glycoprotein genes of three other AR339 sequence. HRsp differed form the consensus sequence by eight coding changes, and TRSB differed by three coding changes. In the 5' untranslated region, HRsp differed from the consensus sequence at nucleotide (nt) 5. These differences were likely the result of cell culture passage of the original AR339 isolate. At three of the difference loci (one in TRSB and two in HRsp), selection of cell-culture-adaptive mutations was documented with Sindbis virus or other alphaviruses. Selection in cell culture often results in attenuation of virulence in animals. Considering the TRSB and HRsp sequences together, one noncoding difference from the consensus (an A-for-G substitution in the 5' untranslated region at nt 5) and six coding differences in the glycoprotein genes (at E2 amino acids 1, 3, 70, and 172 and at E1 amino acids 72 and 237) were at loci which, either individually or in combination, significantly affected alphavirus virulence in mice. Although the levels of virulence of isogenic strains containing either nt 5 A or nt 5 G did not differ significantly in neonatal mice, the presence of nt 5 A greatly enhanced the effect of a second attenuating mutation in the E2 gene. These results suggest that minimal differences in the "wild type" genetic background into which an additional mutation is introduced can have a dramatic effect on apparent virulence and pathogenesis phenotypes. A cDNA clone of the consensus AR339 sequence, a sequence devoid of occult attenuating mutations introduced by cell culture passage, will allow the molecular genetic examination of cell culture and in vivo phenotypes of a virus which may best reflect the sequence of Sindbis virus AR339 at the time of its isolation

Value relevance of corporate governance and the level of voluntary disclosure of Singapore listed companies.

This paper seeks to give an insight into how corporate governance and voluntary disclosure both interact to influence the market value of manufacturing companies that are listed on Singapore Stock Exchange whilst controlling for other variables like book value and earnings

Genomics in practice - a review of inherited cardiac conditions

Interest in inherited cardiovascular conditions (ICCs) is fueled by resources devoted to its diagnosis, management, and research. The rapid advancement of DNA genomic sequencing deepens our understanding of ICCs. The ICC genomic landscape empowers the development of diagnostic guidelines and the discovery of potential therapeutic targets and promises novel therapeutics, especially in precision cardiology. Therefore, it is essential for healthcare institutes and systems to develop contextual frameworks based on current guidelines to provide holistic care for patients with ICCs. The clinical frameworks and considerations described in this review provide an overview of the operations of an ICC clinic, including wet and dry lab conditions, work performed by a healthcare professional, and the variety of cases, ranging from cardiomyopathies to arrythmias to aortopathies. Insights from our experience in an ICC clinic in Singapore add to the discussion of the challenges and benefits for patients and clinicians who serve them

Search for associated production of dark matter with a Higgs boson decaying to bbˉb\bar{b} or γγ\gamma\gamma at s\sqrt{s} = 13 TeV

A search for dark matter is performed using events with large missing transverse momentum and a Higgs boson decaying either to a pair of bottom quarks or to a pair of photons. The data from proton-proton collisions at a center-of-mass energy of 13 TeV, collected with the CMS detector at the LHC, correspond to an integrated luminosity of 2.3 inverse-femtobarns. Results are interpreted in the context of a Z'-two-Higgs-doublet model, where a high-mass resonance Z' decays into a pseudoscalar boson A and a CP-even scalar Higgs boson, and the A decays to a pair of dark matter particles. No significant excesses are observed over the background prediction. Combining results from the two decay channels yields exclusion limits in the signal cross section in the m[Z']-m[A] phase space. The observed data exclude, for Z' coupling strength g[Z'] = 0.8 and m[A] = 300 GeV for example, the Z' mass range of 600 to 1860 GeV. This is the first result on a search for dark matter produced in association with a Higgs boson that includes constraints on h to gamma-gamma obtained at sqrt(s) = 13 TeV

Search for heavy resonances decaying into a vector boson and a Higgs boson in final states with charged leptons, neutrinos, and b quarks

A search for heavy resonances decaying to a Higgs boson and a vector boson is presented. The analysis is performed using data samples collected in 2015 by the CMS experiment at the LHC in proton-proton collisions at a center-of-mass energy of 13 TeV, corresponding to integrated luminosities of 2.2-2.5 inverse femtobarns. The search is performed in channels in which the vector boson decays into leptonic final states ($\mathrm{Z} \to \nu\nu$, $\mathrm{W}\to \ell \nu$, and $\mathrm{Z} \to \ell \ell$, with $\ell = \mathrm{e}$, $\mu$), while the Higgs boson decays to collimated b quark pairs detected as a single massive jet. The discriminating power of a jet mass requirement and a b jet tagging algorithm are exploited to suppress the standard model backgrounds. The event yields observed in data are consistent with the background expectation. In the context of a theoretical model with a heavy vector triplet, a resonance with mass less than 2 TeV is excluded at 95% confidence level. The results are also interpreted in terms of limits on the parameters of the model, improving on the reach of previous searches