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: Italian olive tree disease stumps EU

add to favorites email to friend print save as pdf

Related Stories

From a drop of blood, a clone

Aug 16, 2013

Over the last few decades, scientists have drawn upon a powerful arsenal of biotechnology techniques to establish a wide variety of genetically engineered mouse strains. These animals represent invaluable ...

Recommended for you

Italian olive tree disease stumps EU

3 hours ago

EU member states are divided on how to stop the spread of a disease affecting olive trees in Italy that could result in around a million being cut down, officials said Friday.

China starts relocating endangered porpoises: Xinhua

9 hours ago

Chinese authorities on Friday began relocating the country's rare finless porpoise population in a bid to revive a species threatened by pollution, overfishing and heavy traffic in their Yangtze River habitat, ...

A long-standing mystery in membrane traffic solved

10 hours ago

In 2013, James E. Rothman, Randy W. Schekman, and Thomas C. Südhof won the Nobel Prize in Physiology or Medicine for their discoveries of molecular machineries for vesicle trafficking, a major transport ...

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.