Alternative splicing (AS) events found in Physcomitrella . (A) Total AS events and top five most common types of AS. The intron-exon structure of the AS events and its description is illustrated on the left. In each table, the first column represents the initial number of events found in combined samples, then the frequency of the event among all AS events, the number and percentage of moss genes (annotated: 32,272) showing the event, and the number of statistically significant events. AS events were statistically significant at P <0.001. AltA, alternative acceptor site; AltD, alternative donor site; AltDA, alternative donor/acceptor site; ES, exon skipping; IR, Intron retention. (B) Venn diagrams of IR events in red- and blue-light samples. The diagrams compare all IR events (left) and statistically significant IR events (right) found in red- and blue-light samples.