Mouse stem cell line advance suggests potential for IVF-incompetent eggs

Feb 19, 2007

Researchers have found that mouse oocytes that fail to become fertilized during in vitro fertilization are nevertheless often capable of succeeding as "cytoplasmic donors" during a subsequent cloning step using so-called nuclear transfer. Although the implications for human eggs are not yet clear, the findings are of interest because of the ethical and practical concerns surrounding the need for fresh human oocytes for similar nuclear-transfer procedures using human cells.

The findings, reported by Teruhiko Wakayama, Sayaka Wakayama, and colleagues at RIKEN Kobe in Japan, appear in the February 20th issue of the journal Current Biology, published by Cell Press.

Human IVF is now routinely practiced in fertility clinics, but a proportion of oocytes fail to become fertilized in these procedures. In the new work, researchers examined the ability of day-old mouse oocytes that fail to become fertilized in vitro—"aged, fertilization-failure" (or AFF) oocytes—to succeed in a standard cloning procedure in which the oocyte's nucleus is removed and replaced by the nucleus of a somatic cell. Although this nuclear-transfer procedure showed a lower rate of success in the very first stages of cloning compared to nuclear transfer with fresh oocytes, the early (morulae- or blastocyst-stage) mouse embryos derived from nuclear transfer using AFF oocytes showed similar rates of success in giving rise to embryonic stem cell lines.

None of the AFF-derived mouse embryos tested were capable of developing to full term, and in general, cloning by nuclear transfer sees a low success rate even when fresh eggs are used. But the authors indicate that nuclear-transfer protocols have yet to be perfected, and that the new findings suggest that once techniques required for human nuclear transfer have been optimized, it may be possible to use oocytes that failed to fertilize during IVF attempts and would otherwise be discarded.

Source: Cell Press

Explore further: Fire linked to dieback spread

Related Stories

Research prompts rethink of enzyme evolution

7 hours ago

New research by scientists at New Zealand's University of Otago suggests a need for a fundamental rethink of the evolutionary path of enzymes, the proteins vital to all life on Earth.

Elderly crickets are set in their ways, study finds

7 hours ago

As insects grow old their behaviour becomes increasingly predictable according to new research published in the journal Behavioural Ecology. The study, which set out to understand how personality alters with a ...

Recommended for you

Just like humans, dolphins have social networks

23 minutes ago

They may not be on Facebook or Twitter, but dolphins do, in fact, form highly complex and dynamic networks of friends, according to a recent study by scientists at Harbor Branch Oceanographic Institute (HBOI) ...

Norway plans to slash subsidies to fur farms

28 minutes ago

Norwegian fur farmers denounced Tuesday a government proposal to slash financial support to the controversial industry and warned that it could lead to farm closures in vulnerable rural areas.

Hitting the borders of expansion

4 hours ago

Why does a species not adapt to an ever-wider range of conditions, gradually expanding its geographical range? In their paper published on May 5 in PNAS (Proceedings of the National Academy of Sciences), Jitka Polecho ...

Fire linked to dieback spread

5 hours ago

Fire has the potential to increase the range and severity of Phytophthora dieback in native plant communities infected with the disease, suggests a study at the Stirling Range National Park near Albany.

How mixing light with salt makes a smolt?

5 hours ago

For decades, researchers have tried to find out what regulates changes in salmon when they transform from being freshwater to saltwater fish. Now they have come a little closer to an answer.

User comments : 0

Please sign in to add a comment. Registration is free, and takes less than a minute. Read more

Click here to reset your password.
Sign in to get notified via email when new comments are made.