Fig. 1.

Integrations of gene trap vectors into gene length segments of long non-coding RNA (lncRNA) genes and protein-coding genes (PCGs), measured as distance from the transcription start site. Each individual gene has been subdivided into ten equal-length segments. lncRNA genes are shown in blue, PCGs in red. (A) Promoter trap vectors with splice acceptor (n=196,565). (B) PolyA-trap vectors (n=4220). All integrations were analyzed with genomic PCR technologies (see Table S1 for composition of the vector classes). The significance of the integration pattern into gene length segments was studied with a G-test of goodness-of-fit (all P-values <10⁻¹⁶). rel. units, relative units.