Special Delivery: A New Way To Transport Sperm

In a seminal development, researchers from Japan have successfully mailed freeze-dried mouse sperm via a postcard.

AsianScientist (Aug. 17, 2021) – Talk about a surprise in the mailbox: scientists in Japan have successfully sent freeze-dried mouse sperm through the post. Their research, published in iScience, paves the way for new methods to preserve genetic resources.

In the world of biological research, the humble mouse stands as one of its most prominent workhorses. Using mice, scientists have identified everything from the mechanism of action of the Zika virus to candidate genes for bipolar disorder.

The same holds true for research on fertility and reproduction. Consider the literally out-of-this-world work done by Professor Teruhiko Wakayama from the University of Yamanashi. In 2017, Wakayama’s team was the first to successfully freeze-dry and preserve mouse sperm, which they then sent to the International Space Station to study the effects of space radiation of baby mice.

In the current study, the team originally housed mouse sperm in glass ampoules. Unfortunately, they were prone to breakage, rendering the samples useless. While the team needed large volumes of mouse sperm to carry out their research in space, cushions had to be used to prevent breakage during the rocket launch—limiting the amounts of samples that could be carried.

To address these setbacks, Wakayama’s team sought to develop a new preservation that required little space and resulted in no breakage. Though plastic sheets appeared to be a compact option for carrying sperm, they were toxic. Hence, the team tried a different approach, testing six different materials instead to go inside the plastic sheets.

They found that weighing paper—a lightweight and sturdy sheet of paper used for measuring powdery substances—was the easiest to handle, transport and did not compromise sperm preservation. In fact, even after the samples were mailed within a ‘sperm book’ of postcards attached to plastic sheets at room temperature without any protection, the sperm remained viable.

According to the authors, once perfected, the sperm book and mailing method have the potential to support wider research and collaboration. Currently, the team is working on a method that would allow sperm storage for at least one month at room temperature. Eventually, they hope to freeze-dry sperm that can rehydrate and come back to life for fertilization.

“Genetic resources are an asset to humanity’s future,” said Wakayama. “The plastic sheet preservation method in this study will be the most suitable method for the safe preservation of valuable genetic resources because of the resistance to breakage and less space required for storage.”

The article can be found at: Ito et al. (2021) Mailing viable mouse freeze-dried spermatozoa on postcards..


Source: University of Yamanashi; Illustration: Alexandra Valino/Asian Scientist Magazine.
Disclaimer: This article does not necessarily reflect the views of AsianScientist or its staff.

Asian Scientist Magazine is an award-winning science and technology magazine that highlights R&D news stories from Asia to a global audience. The magazine is published by Singapore-headquartered Wildtype Media Group.

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