SRP385131 PRJNA856274 Thyroid transcriptome sequencing Circular RNAs (circRNAs) are non-coding RNAs newly identified and play important roles in RNA regulation. However, little is known regarding photoperiods induced circRNAs in the thyroid gland. In this study, we performed a comprehensive analysis of circRNA profiles in the thyroid gland of OVX+E2 ewes at different photoperiods by whole transcriptome sequencing.