Cryopreserving animal genetic resources
Cryopreservation is a technique and important component of agriculture in which genetic materials are preserved for long-term storage, selective breeding, conservation or safeguarding purposes.
What is cryopreservation?
Cryopreservation works by getting samples to cool quickly enough to prevent ice crystals from forming inside cells. This is essential for halting biological activity and preserving them in a state of suspended animation.
Cryoprotectants are used to reduce damage during freezing and thawing. These chemicals, such as DMSO and glycerol, work by binding water molecules to form strong hydrogen bonds, preventing water from organizing into damaging ice crystals that rupture cells. Additionally, they help maintain normal cell water balance (osmolarity) as water leaves the cell during cooling, reducing osmotic shock.
Samples are cooled to extreme temperatures where metabolic processes stop completely. At this state, their integrity is maintained until the samples are thawed for future use.
Key applications
Cryopreservation in animal husbandry finds several applications:
Artificial insemination: cryopreservation is a cornerstone of AI, allowing breeders to use genetic material from superior males.
Genetic preservation: for protected and endangered species, biobanks protect genetic material to combat genetic drift and fragmentation, safeguarding biodiversity. Biobanks store sperm, oocytes, embryos, and even somatic tissues as a hedge against disease outbreaks, natural disasters, or inbreeding that could otherwise lead to the loss of valuable genetic lines.
Selective breeding: allows access to superior genetics to produce offspring with the desired qualities, even long after sample collection.
Genetic engineering: preserves genetically modified lines for future research and recovery.
Disease control: transporting cryopreserved genetic material (sperm or embryos) instead of live animals reduces the risk of spreading pathogens between facilities or countries.
Liquid nitrogen can also be used in applications involving cryosurgery and freeze branding.
The role of liquid nitrogen
Liquid nitrogen plays a critical role in animal cryopreservation because of its ability to maintain extremely low temperatures.
What makes liquid nitrogen indispensable for cryopreservation?
- Ultra-low temperature
- Prevents ice crystals from forming
- Enables long-term viability
- Availability