Cryopreservation of Xenopus Sperm and In Vitro Fertilization Using Frozen Sperm Samples.

Area of Science:

• Amphibian reproductive biology
• Cryobiology
• Xenopus genetics

Background:

• Maintaining live animal colonies for Xenopus research is resource-intensive.
• Archiving and exchanging genetically altered (GA) Xenopus lines can be challenging.
• Improving animal welfare and cost-efficiency in Xenopus research is a priority.

Purpose of the Study:

• To develop a straightforward protocol for cryopreserving Xenopus sperm.
• To enable efficient archiving and sharing of Xenopus genetic resources.
• To reduce the number of animals required for Xenopus research.

Main Methods:

• Sperm collected from Xenopus laevis or Xenopus tropicalis testes.
• Maceration in Leibovitz's L-15 medium with an egg yolk and sucrose cryoprotectant.
• Slow freezing overnight at -80°C in a polystyrene box.

Main Results:

• Successful cryopreservation of Xenopus sperm using standard laboratory equipment.
• Xenopus sperm can be stored at -80°C, unlike mouse sperm requiring liquid nitrogen.
• Frozen sperm are viable for in vitro fertilization.

Conclusions:

• Cryopreservation offers a cost-effective and welfare-friendly method for Xenopus sperm storage.
• This protocol facilitates easier management and exchange of Xenopus GA lines.
• Simplified cryopreservation improves the efficiency of Xenopus research.