# Multi-Omics Investigation into Why Viable Oogonial Stem Cells Can Still Be Isolated and Cultured from Post-Mortem Paralichthys olivaceus

## TL;DR

This study explores how long viable oogonial stem cells can be preserved in a marine fish after death and identifies key biological pathways and markers for their survival.

## Contribution

The study identifies specific genes and metabolites as biomarkers for post-mortem OSC viability in fish.

## Key findings

- OSCs remained viable and culturable after 15 h at 19 °C and 24 h at 4 °C post-mortem.
- Ferroptosis and fatty acid metabolism pathways were most enriched in post-mortem ovarian tissue.
- Genes like vdac2, p53, and slc7a11 and metabolites like adrenic acid are reliable viability biomarkers.

## Abstract

The cryopreservation and transplantation of germline stem cells (GSCs) have become the key to conserving fish genetic resources and safeguarding species diversity. This study aimed to investigate the effects of post-mortem temperature and time on the preservation of oogonial stem cells (OSCs) in the marine fish Paralichthys olivaceus. OSCs remained viable after fish death, and they remained viable and could be cultured after storage at 19 °C for 15 h and at 4 °C for 24 h. Combined transcriptomic and metabolomic analysis was used to identify the pathways leading to OSC death. Several genes were differentially expressed in the ovarian tissue post-mortem, with the most enriched pathways being ferroptosis, fatty acid metabolism/biosynthesis, glutathione metabolism, citric acid cycle (TCA cycle), and arachidonic acid metabolism signaling pathways. Genes related to ferroptosis, such as vdac2, p53, and slc7a11, as well as metabolites such as adrenic acid and arachidic acid, can serve as reliable biomarkers for evaluating the viability of post-mortem OSCs. These findings provide valuable insights and theoretical support for the effective use of post-mortem GSCs and enhance strategies for germplasm resource conservation in fish.