What is the biological function of the SRY circular RNA (circRNA)?
We suggest that the circles arise from normal splicing processes as a consequence of the unusual genomic structure surrounding the Sry locus in the mouse. While this result does not prove a direct interaction between the two genes, it defines the critical period during which Sry must act to initiate Sertoli cell differentiation. We also attempted to make clear whether the equine SRY gene transcript is expressed in the adult testis, and whether the type of transcript is expressed as linear or circular RNA. We further show that the testis-specific circRNA, sex-determining region Y (Sry), serves as a miR-138 sponge, suggesting that miRNA sponge effects achieved by circRNA formation are a general phenomenon Recent studies have mainly been devoted to the function of the circular RNA sponge for miR-7 (ciRS-7) and sex-determining region Y (SRY) by targeting microRNA-7 (miR-7) and microRNA-138 (miR-138), respectively However, the characteristics and the critical role of circRNA in co-/post-transcriptional regulation were not well recognized until the "microRNA sponge" function of circRNA is discovered