Rapid Isolation of Stage I Oocytes in Zebrafish Devoid of Granulosa Cells

The study of oocyte development holds significant implications in developmental biology. The zebrafish (Danio rerio) has been extensively used as a model organism to investigate early developmental processes from oocyte to embryo. In zebrafish, oocytes are surrounded by a single layer of somatic granulosa cells. However, separating granulosa cells from oocytes poses a challenge, as achieving pure oocytes is crucial for precise analysis. Although various methods have been proposed to isolate zebrafish oocytes at different developmental stages, current techniques fall short in removing granulosa cells completely, limiting the accuracy of genome analysis focused solely on oocytes. In this study, we successfully developed a rapid and efficient process for isolating pure stage I oocytes in zebrafish while eliminating granulosa cell contamination. This technique facilitates biochemical and molecular analysis, particularly in exploring epigenetic and genome structure aspects specific to oocytes. Notably, the method is user-friendly, minimizes oocyte damage, and provides a practical solution for subsequent research and analysis.