(A) Association between the 5 nt transcription initiation sequence and the position of the anchor in cassette-associated expressed canonical gRNA genes. IUPAC codes: B = {C, G, T}, N = {A, C, G, T}. Position 1 corresponds to complete overlap of the anchor with the initiation sequence. The number of genes, represented by the size of the circles, is indicated for some cases. (B) Association between the 5 nt transcription initiation sequence and the mean 5′ oligo(A) tail length of transcripts whose 5′ ends map to a cassette's initiation site for expressed canonical (blue) and noncanonical (orange) genes. Box plots: box represents the interquartile range (IQR), mid-line represents the median, whiskers represent 1.5 × IQR.
