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Test tube sperm successfully grown for the first time

Scientists have grown viable sperm from newborn mouse testicular tissue, raising hopes for combating male infertility at any age.

Scientists have taken cells from mouse testes and successfully produced sperm in a test tube (well, a dish actually) – an unprecedented feat for the field of male infertility.

Spermatogenesis – the creation of sperm – has been difficult to recreate outside of mammal testes. Biologists have tried in the lab and failed for centuries.

So a team of Japanese scientists led by Takehiko Ogawa of Yokohama City University designed a way to culture sperm and allow them to mature outside of the body.

  1. They took tissue fragments from newborn mouse testes. Since the mice were only 2 or 3 days old, they didn’t already have mature sperm.
  2. Then they soaked the testes tissue in a mixture called KnockOut Serum Replacement, often used to grow embryonic stem cells.
  3. After several weeks in the mix, the testes looked normal and were producing sperm. Nearly half of the samples contained cells with sperm-like tails (pictured).
  4. Finally, they took the resulting sperm, injected them into egg cells, and then artificially inseminated surrogate female mice.
  5. Those sperm ended up siring a dozen healthy and fertile mouse pups.

In fact, the testes continued to make sperm for two more months. And sperm was also produced from testicular tissue that was frozen in liquid nitrogen for several weeks.

Eventually, the researchers hope to culture pieces of testis removed in biopsies from humans and produce functional sperm that could be used for in vitro fertilization (IVF).

The technique holds significant promise for male infertility, which afflicts 2 million men in the US. As ScienceNOW explains, many infertile men who don't produce sperm have normal reproductive stem cells, and with modifications to Ogawa's technique, culture of testis biopsies from these men or men with testicular cancer could allow them to develop sperm.

By growing sperm cells that can be frozen, the technique could also aid prepubescent boys about to undergo cancer therapies that destroy fertility, Nature News reports. While men can have their sperm frozen before cancer treatment, this research suggests that boys could have testicular tissue removed before chemotherapy or radiation.

"It will be useful for diagnosis and treatment of infertility in future, for sure," says Ogawa, who adds that the sperm-growing procedure shouldn't be expensive.

The study was published in Nature today.

Image: Sato et al., Nature

This post was originally published on Smartplanet.com