Establishment and Characterization of an Oogonial Stem Cell Line from the Yellow River Carp (Cyprinus carpio haematopterus)

Germline stem cells (GSCs) have essential roles in aquaculture, contributing to reproduction, genetic improvement, and germplasm conservation. Here, we established an oogonial stem cell (OSC) line from the ovaries of 10-month-old Yellow River carp (Cyprinus carpio haematopterus) via tissue explant culture. Maintained for over 60 passages at 30 °C, the cells exhibited a stable 3–4-day subculturing interval in optimized Leibovitz’s L-15 medium. The line showed typical germline morphology, high alkaline phosphatase activity, and a diploid karyotype (2n = 100). The expression of germ cell markers (vasa, foxl2a, nanos1, nanos3) and stemness markers (klf4-2, plzf), together with the absence of the somatic marker dmrt1, confirmed the identity and purity of the line. Upon 11-ketotestosterone induction, OSCs formed embryoid body-like clusters. Additionally, xenotransplantation experiments into zebrafish embryos suggested that the cells could integrate into certain regions within the recipient gonadal area. While further research is necessary to confirm functional outcomes, this OSC line provides a promising experimental platform for germplasm preservation and cell-based biotechnology in Yellow River carp.