The selected strains were used for loxP excision analysis. These procedures are schematically drawn in Fig. 4A. loxP excision analysis by PCR Cells were lysed in guanidine solution (4 M guanidine thiocyanate, 0.5% N-lauroyl sarcosine sodium, 25 mM Tris-HCl pH 8.0, 0.1 M 2-mercaptoethanol) and genomic DNA was extracted by conventional extraction with phenol/chloroform (1:1) and precipitated with isopropanol. The loxP-neo4-loxP-EGFP-TWI1 locus

or the neo4-excised loxP-EGFP-TWI1 locus was detected using the PCR Extender System (5-PRIME) with the primers TWI15LoxFW and EGFP-NtermRV. Observation of EGFP-Twi1p loxP-EGFP-TWI1 cells were mated with the wild-type B2086 strain. Cells were fixed and stored in 25% methanol and 10% formaldehyde over night at 4°C. The samples were incubated with 10 ng/mL DAPI and observed by LY3023414 manufacturer fluorescence microscopy. Acknowledgements We thank all the members

of the Mochizuki group for their useful discussion. The research leading to these results received funding from the European Research Council (ERC) Starting Grant (204986) under the European Community’s Seventh Framework Program and from the Austrian Academy of Sciences to KM. Electronic supplementary material Additional file 1: Supplementary Figure S1 and plasmid DNA sequences. Supplementary Figure S1 describing construction and analyses of a VS-4718 Tetrahymena strain expressing Cre-recombinase from BTU1 locus, and DNA sequences of pMNMM3, pMNMM3-HA-cre1 and pBNMB-HA-cre1 (PDF 360 KB) References 1. Brizzard B: Epitope tagging. BioTechniques 2008,44(5):693–695.PubMedCrossRef 2. Cassidy-Hanley find more D, Bowen J,

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