Table 1.

Frequency of 8mers extracted upstream from the annotated vector clip point in shotgun reads from Xanthomonas oryzae pv. oryzae PX099A

Trace direction	Forward		Reverse
Number of reads	3687		4310
Four most frequent   8mers and frequency	GCGCAGCG	40	GCGCAGCG	46
	GCCGCAGC	29	GTGCTGGA	42
	GATCCATT	29	GGCGATCG	37
	GTGCTGGA	26	TGGCCGAT	35
Number of distinct   8mers	1679 (45.5%)		1858 (43.1%)

We only considered reads from the library where the 5′ vector clip point was at least 8 bp to the right of the 5′ quality clip point. The reads were further binned by sequencing direction. The four most frequent 8mers are shown together with their frequency. The high level of variability indicates errors in the reported clipping coordinates.