Comparison of the RICESLEEPER 1 and 2 loci . Coding regions and part of the 5’and 3’UTR’s are ~97% identical. RICESLEEPER1 and 2 each have obtained a new 5’UTR sequence, which is not homologous to that of the other locus. A and B display two different transcription models found by PCR for RICESLEEPER2. Transcription model B has most likely acquired sequence material from a retrotransposon insertion in an intron on the opposite strand. Short duplications were found flanking the zones of homology in both genes, which are shown in arrowed boxes. The small arrows represent PCR primers, which were designed on available rice gene expression data, and were used to obtain RICESLEEPER1 and 2 transcripts from a cDNA library. Primer descriptions can be found in Additional file 3: Table S2.