The alternative AID splice variants were PCR amplified (Phusion Pol, Thermo Scientific) from cDNA of CLL or MEC1 cells using primers RG460 and RG461 followed by TOPO-cloning (Invitrogen). Positive clones were verified by sequencing (MWG Eurofins) and used as templates for size-standard control-PCRs.
For cloning of AID splice variants as C-terminal fusion to GFP, TOPO-cloned splice variants were PCR amplified using primers RG486 and RG487 (Phusion Pol, Thermo Scientific). Gel-purified PCR products (Qiagen) were cloned into the pEGFP-C3 vector using BamHI and HindIII restriction enzymes (Fermentas). Sequences of plasmids were confirmed by sequencing (MWG Eurofins). Primer sequences are listed in the Supporting Information.
For cloning of AID splice variants as C-terminal fusion to GFP, TOPO-cloned splice variants were PCR amplified using primers RG486 and RG487 (Phusion Pol, Thermo Scientific). Gel-purified PCR products (Qiagen) were cloned into the pEGFP-C3 vector using BamHI and HindIII restriction enzymes (Fermentas). Sequences of plasmids were confirmed by sequencing (MWG Eurofins). Primer sequences are listed in the Supporting Information.