Worm Breeder's Gazette 9(3): 58
These abstracts should not be cited in bibliographies. Material contained herein should be treated as personal communication and should be cited as such only with the consent of the author.
We have continued the analysis of C.
described in the Nov. '85 Gazette. Several
introns from collagen and other genes have been added to the worm
intron data set, enlarging it to 72 examples.
The consensus sequence 5'-GTAAGTT ... TTTCAG-3' for C.
plice junctions derived from the original
data set of 53 introns also accurately describes the splice junctions
in the larger data set. m e underlined nucleotides are absolutely
conserved. An A has been found in the -3 position in the 3' junction
in two cases; G has not been observed in this position.
We have re-examined the question of whether a lariatforming
consensus sequence exists in C. ted
previously, many worm introns lack the eukaryotic consensus lariat-
forming sequence YNYTRAY (R=purine, Y=pyrimidine). We have performed a
new search of the larger data set for any weaker consensus sequence.
78% of the 72 introns were found to contain the sequence YRAY; the
remaining 22% contain either YRAR or RRAY. The consensus sequence
derived from this search
is:
{Figure 1}
where the underlined RA is absolutely conserved, and the remaining
nucleotides occur at the indicated frequencies. 89% of these sequences
occur between positions -15 and -35, with respect to the conserved G
of the 3' splice junction.
In the absence of experimental data, it is unclear whether this
consensus sequence plays any role in worm splicing. We are performing
an information-theoretic analysis of the regions of the introns
surrounding these sequences in order to assess the statistical
significance of the consensus.