Genome Wide Transcript and Methylation Changes in the Sheep Seasonal Clock

The circannual clock drives yearly rhythms, in both plants and animals, to meet the challenges of a changing seasonal environment. For many agricultural species the yearly timing of growth, metabolism and reproduction is synchronized to the changing length of day (photoperiod). We investigated epigenetic and transcriptional changes in sheep calendar cells of the pituitary pars tuberalis (PT). We present the bioinformatics analysis of a photoperiod controlled environment experiment in sheep, measuring genome wide transcription (RNASeq) and DNA methylation (RRBS) within two 24 hour time series, in short and long photoperiods. We applied regression, clustering and circadian analysis to reveal photoperiod and time dependent changes in gene expression. We observed seasonal phase peak adjustments in clock controlled genes together with genome wide changes in expression and DNA methylation.

Funded by BBSRC grant BB/N015347/1