Researchers put embryo development 'on hold' in mice

Scientists say they were able to halt development of early mouse embryos for up to a month in the lab before they resumed normal growth.
This research could prove important in areas such as assisted reproduction, regenerative medicine, aging and even cancer, according to the team from the University of California, San Francisco (UCSF). The investigators used drugs that dampen the activity of a cell growth regulator called mTOR to put these early mouse embryos (blastocysts) into a stable and reversible state of suspended animation for up to four weeks.
When no longer exposed to the mTOR inhibitors, the embryos quickly resumed normal growth and developed into healthy mice when implanted back into adult female mice, the study authors said.
"Normally, blastocysts only last a day or two, max, in the lab. But blastocysts treated with mTOR inhibitors could survive up to four weeks," lead author Aydan Bulut-Karslioglu, said in a university news release. She's a post-doctoral researcher in the lab of senior author Miguel Ramalho-Santos, an associate professor of obstetrics/gynecology and reproductive sciences at UCSF.
The findings surprised the researchers, who launched the study to learn how mTOR-inhibiting drugs slow cell growth in blastocysts.
"It was completely surprising. We were standing around in the tissue culture room, scratching our heads, and saying wow, what do we make of this?" Ramalho-Santos said in the news release.
"To put it in perspective, mouse pregnancies only last about 20 days, so the 30-day-old 'paused' embryos we were seeing would have been pups approaching weaning already if they'd been allowed to develop normally," he explained.
It may be possible to put mouse embryos in suspended animation for much longer than the four weeks achieved in this study, the researchers suggested.
HealthDay

 

Researchers put embryo development on hold in mice

Scientists say they were able to halt development of early mouse embryos for up to a month in the lab before they resumed normal growth. This research could prove important in areas such as assisted reproduction, regenerative medicine, aging and even cancer, according to the team from the University of California, San Francisco (UCSF). The investigators used drugs that dampen the activity of a cell growth regulator called mTOR to put these early mouse embryos (blastocysts) into a stable and reversible state of suspended animation for up to four weeks. When no longer exposed to the mTOR inhibitors, the embryos quickly resumed normal growth and developed into healthy mice when implanted back into adult female mice, the study authors said. Normally, blastocysts only last a day or two, max, in the lab. But blastocysts treated with mTOR inhibitors could survive up to four weeks, lead author Aydan Bulut-Karslioglu, said in a university news release. Shes a post-doctoral researcher in the lab of senior author Miguel Ramalho-Santos, an associate professor of obstetrics/gynecology and reproductive sciences at UCSF. The findings surprised the researchers, who launched the study to learn how mTOR-inhibiting drugs slow cell growth in blastocysts. It was completely surprising. We were standing around in the tissue culture room, scratching our heads, and saying wow, what do we make of this? Ramalho-Santos said in the news release. To put it in perspective, mouse pregnancies only last about 20 days, so the 30-day-old paused embryos we were seeing would have been pups approaching weaning already if theyd been allowed to develop normally, he explained. It may be possible to put mouse embryos in suspended animation for much longer than the four weeks achieved in this study, the researchers suggested. HealthDay