Table I. Analysis of lariat-specific cDNAs after cloning.

Branch-points are presented in grey boxes as shown to the upper left, and sequences obtained from cDNA clones (sense strand) are listed in white boxes below. The 5′ intron end (5′ I) is linked to the branch-point A in the intron 3′ part (3′ I). Nucleotides downstream of bulge A (3′ I tail) including the first two of the 3′ exon (3′ E; lower case) are in blue. The branch-point as well as positions that deviate from the expected lariat cDNA sequence are in green. Several independent cDNA pools raised from untreated (C1–C4) or ligase-treated barley RNA (LH and LU; as in Figure 2) were analysed for a number of introns including trnK which previously was shown to form lariats (Vogel etal., 1997a). Lariat cDNAs from other plants (Nt, tobacco; Pa, spruce; Zm, maize) were raised from untreated RNA. The number of inserts with a specific cDNA type is given out of the total analysed for each cloned PCR band (e.g. 13/14). The branch-point A was found to be represented overwhelmingly as T in the cDNA sequences.