Preservation of female genetic resources of common carp through oogonial stem cell manipulation

Area of Science:

• Aquaculture and Reproductive Biology
• Cryobiology and Germplasm Preservation
• Fish Cell Biology

Background:

• Oogonial stem cells (OSCs) are crucial for fish reproduction and aquaculture.
• Efficient cryopreservation methods are needed for long-term germplasm storage of common carp.
• Current short-term storage methods lack long-term viability for OSCs.

Purpose of the Study:

• To develop an optimal slow-rate freezing protocol for common carp ovarian tissue fragments, focusing on OSCs.
• To evaluate cryoprotectants and sugar supplements for enhanced OSC cryosurvival.
• To assess short-term storage alternatives and validate cryopreserved OSCs through transplantation.

Main Methods:

• Slow-rate freezing (-1°C/min) with various cryoprotectants (DMSO, propylene glycol, methanol) and sugar supplements (glucose, trehalose, sucrose).
• Immunocytochemistry and trypan blue exclusion test for OSC identification and viability assessment.
• PKH-26 labeling and interspecific transplantation into goldfish recipients, followed by RT-PCR analysis.

Main Results:

• 1.5 M dimethyl sulfoxide (Me2SO) was the optimal cryoprotectant.
• 0.3 M glucose and trehalose were the best sugar supplements.
• The optimized protocol achieved ~65% viability for frozen/thawed OSCs, with successful transplantation confirmed in recipients.

Conclusions:

• An effective cryopreservation protocol for common carp OSCs using slow-rate freezing was established.
• This method facilitates long-term germplasm preservation, enabling future recovery through interspecific germ cell transplantation.
• The findings support conservation efforts and genetic resource management in common carp aquaculture.