The L4 family of mRNAs. Alternative spliced mRNAs detected from late region 4 are shown. The numbers of reads identified at 12, 24, and 36 hpi are shown in boxes on the right, with previously described transcripts in bold in shaded boxes. Thick lines denotes exons, thin lines introns. Triangles (up or down) show microheterogeneities in 100K 3′ splice site usage. Circles and squares similarly show heterogeneities in 22K and 33K 3′ splice site usage. Gray boxes indicate the proposed proteins expressed from the respective mRNA. Poly-A, polyadenylation site. For a complete summary of the triple-verified L4 mRNAs, see Table S1.