Whole transcriptome profiling of the rat pineal gland during development from embryonic day 21 to adult

The transcriptome of the rat pineal gland is highly dynamic, with many hundreds of genes changing more than two-fold on a 24-hr daily rhythm, as revealed earlier using Affymetrix GeneChip analysis. Several key transcription factors and enzymes are known to change dramatically during development of the pineal gland. Studies on a small number of genes indicate that the onset of rhythmic expression generally occurs later in development. This study characterizes this temporally dynamic transcriptome using RNA-Seq to capture information regarding alternative splicing, novel exons, unannotated mRNAs, non-coding RNAs and coding transcripts not represented on the Affymetrix chips. The rat pineal transcriptome was sequenced in samples from four ages, from embryonic day 21 through adult. At each age, samples were taken at mid-day and mid-night. Data were collected to describe the changes in the developing pineal transcriptome and to identify transcripts that exhibit day/night differences in expression at each age.