Li et al. (2013) described that a single-nucleotide polymorphism (rs2287798) within the human AQP8 gene exhibits a significantly higher allele frequency in PCOS cases compared with that in controls, implying a possible important role of AQP8 in the pathogenesis of PCOS. In the present study, we evaluated the characteristics of the follicular antrum in AQP8-deficient mice by ovary sectioning and staining, and observed a phenotype with a significantly high number of follicular antrums. A 3D follicular culture approach was employed to represent and confirm the antrum formation process in vitro. The gene discussed is AQP8; the disease is polycystic ovary syndrome.