Fusion of SpCas9 to E.coli Rec A protein enhances CRISPR-Cas9 mediated gene knockout in mammalian cells

Mammalian cells repair double-strand DNA breaks (DSB) by a range of different pathways following DSB induction by the engineered clustered regularly interspaced short palindromic repeats (CRISPR)-associated protein Cas9. While CRISPR-Cas9 thus enables predesigned modifications of the genome, applications of CRISPR-Cas9-mediated genome-editing are frequently hampered by the unpredictable and varying pathways for DSB repair in mammalian cells. Here we present a strategy of fusing Cas9 to recombinant proteins for fine-tuning of the DSB repair preferences in mammalian cells. By fusing Streptococcus Pyogenes Cas9 (SpCas9) to the recombinant protein A (Rec A, NP_417179.1) from E. coli, we create a recombinant Cas9 protein (rSpCas9) which enhances the generation of indel mutations at DSB sites in mammalian cells, increases the frequency of DSB repair by homology-directed single-strand annealing (SSA), and represses homology-directed gene conversion by approximately 33%. Our study thus proves for the first time that fusing SpCas9 to recombinant proteins can influence the balance between DSB repair pathways in mammalian cells. This approach may form the basis for further investigations of the applications of recombinant Cas9 proteins to fine-tuning DSB repair pathways in eukaryotic cells

Measurement of the ratio R = sigma(w) Br (W) ---> mu neutrino) / sigma(Z) Br (Z ---> mu mu) and gamma(W) total at the CERN proton - anti-proton collider

An analysis of W and Z boson production at UA1, using 4.66 pb-1 of data from the 1988 and 1989 CERN ppBAR Collider runs at square root of s = 0.63 TeV, yields R = sigma(w)Br(W --> mu-v)/sigma(z)Br(z --> mu-mu) = 10.4(-1.5)(+1.8)(stat.) +/- 0.8(syst). We find R = 9.5(-1.0)(+1.1)(stat. + syst.) when combining all available UA1 data, in both the electron and muon channel, taken in the period 1983-1989. In the framework of the standard model, the value of R is used to infer the total width of the W boson, I(w) (tot) = 2.18(-0.24)(+0.26) (exp.) +/- 0.04 (theory) GeV/c2

Flavour Physics of Leptons and Dipole Moments.

This chapter of the report of the ``Flavour in the era of the LHC'' Workshop discusses the theoretical, phenomenological and experimental issues related to flavour phenomena in the charged lepton sector and in flavour-conserving CP-violating processes. We review the current experimental limits and the main theoretical models for the flavour structure of fundamental particles. We analyze the phenomenological consequences of the available data, setting constraints on explicit models beyond the Standard Model, presenting benchmarks for the discovery potential of forthcoming measurements both at the LHC and at low energy, and exploring options for possible future experiments.Comment: Report of Working Group 3 of the CERN Workshop ``Flavour in the era of the LHC'', Geneva, Switzerland, November 2005 -- March 200