Specific expression pattern of a novel Otx2 splicing variant during neural differentiation.

We cloned a new splicing variant of Otx2 gene, Otx2c. Otx2c lacks entire exon 4, most of the region encoding the homeodomain. More importantly, Otx2c harbors an early premature stop codon and bioinformatics analysis prefers it to be a non-protein coding RNA. In addition, this splicing variant is not simply a noise during mRNA processing, since it is mainly expressed in undifferentiated human embryonic stem cells but gradually decreased during differentiation. Therefore, we report here that a single pre-mRNA can generate both coding and non-coding RNAs through alternative splicing and this splicing activity is tightly regulated in different cell contexts.