Fosmid recombineering cassettes.

The vector backbone for the pBALU vectors is the pCR TOPO cloning vector (Invitrogen). For complete plasmid sequences, see Supplement Text S1. Note that the intronless cassettes are specifically required to allow for double-recombineering with the intron-containing reporter genes. If there were overlap between the sequentially introduced reporters, undesired homologous recombination could occur. STOP represents the stop codon from the gene of interest. mChO (mChOpti) is an intron containing, and C. elegans codon usage optimized mCherry variant as described in McNally et al., 2006. For each vector series (e.g. pBALU15-18), at least one, if not all, color version was explicitly tested in recombineering reactions. The pBALU vectors that are also available with modified FRTs for double recombineering are labeled pBALUxx*.