Developing a cryopreservation protocol for the forest-forming seaweed Phyllospora comosa as a tool for restoration

Area of Science:

• Marine Biology
• Conservation Genetics
• Cryopreservation Technology

Background:

• Global seaweed forest decline threatens genetic diversity and ecosystem resilience.
• Effective conservation strategies, including cryopreservation, are crucial for vulnerable marine habitats.
• Phyllospora comosa, a fucoid seaweed, faces significant anthropogenic stressors, necessitating preservation methods.

Purpose of the Study:

• To develop a cryopreservation protocol for Phyllospora comosa sperm and germlings.
• To assess the cytotoxicity of common cryoprotectant agents on P. comosa gametes.
• To establish optimal freezing conditions for P. comosa sperm cryopreservation.

Main Methods:

• Tested cryoprotectant cytotoxicity (DMSO, ethylene glycol, glycerol, methanol, propylene glycol) on sperm and germlings.
• Performed freezing trials with varying glycerol concentrations and freezing rates.
• Evaluated post-thaw sperm motility, concentration, and germling viability.

Main Results:

• Cryoprotectants exhibited non-lethal cytotoxic effects, reducing germling length and sperm motility/concentration.
• Successfully cryopreserved P. comosa sperm with 10% glycerol and a freezing rate of -42.4°C/min, achieving 18.7% post-thaw motility.
• Germlings could not be revived post-thaw despite extensive protocol variations.

Conclusions:

• Live Phyllospora sperm can be recovered post-cryopreservation, enabling genetic resource banking.
• Cryopreservation offers potential for enhancing genetic diversity in P. comosa populations.
• Further research is needed to optimize protocols for germling cryopreservation and conservation application.