Detection of circRNA expression patterns in the PBMCs of AS and
control groups
Using a CIRI-based computational pipeline, circRNAs present in RNA-seq
data derived from the PBMCs of AS and control (CN) groups were
predicted. In total, 10,441 distinct candidate circRNAs were detected in
analyzed samples, of which 5,917 (56.7%) were known and 4,524 (43.3%)
were novel in human samples. Overall, 3,432 circRNAs were present only
in the AS group, 2,562 only in the CN group, and 4,447 present in both
groups (Fig. 1A). Of these 10,441 circRNAs, 883 (8.46%) were derived
from introns, 9,303 (89.1%) were generated from exonic sequences, and
the remaining 255 (2.44%) were derived from intergenic regions. 10,186
different circRNAs originating from 3,968 parental genes were detected
in these PBMCs samples, with 1,920 (48.4%) and 2,048 (51.4%) of the
parental protein-coding genes producing one and more than one circRNA,
respectively. A single gene encoding a phosphatidylinositol binding
clathrin assembly protein was found to be the source of 32 different
circRNAs in these samples (Fig. 1B). These circRNAs exhibited a
chromosomal distribution pattern that was roughly consistent with
chromosome size, and chromosomes 1, 2, and 3 produced the most circRNAs
in these analyzed samples (Fig. 1C).