Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:


Long-term benefits from a ‘moment of silence’

By temporarily silencing a hyperactive gene, scientists dramatically boost the efficiency of mouse cloning
In principle, somatic cell nuclear transfer (SCNT) is a potent tool for scientists looking to produce exact genetic replicas of a particular animal. By injecting a nucleus from an adult cell into an oocyte from which the nucleus has been removed, one can initiate the embryonic development process and derive a clone of the ‘donor’ animal.

Unfortunately, this technique is terribly inefficient, with a success rate of 1–2% in mice. “This must be due to some errors in the reprogramming of the donor genome into the ‘totipotent’ state, which is equivalent to the state observed in conventionally fertilized embryos,” explains Atsuo Ogura of the RIKEN BioResource Center in Tsukuba. However, Ogura and colleagues have now made significant progress in clearing a major roadblock thwarting SCNT success.

During development of female mammalian embryos, one of the two X chromosomes is targeted for inactivation, thereby ensuring that both males and females achieve equivalent expression of X-linked genes. This inactivation depends on RNA produced by the Xist gene, which blankets the selected chromosome and sets the inactivation process in motion.
Ogura and his team previously determined that Xist is inappropriately activated in SCNT embryos, impairing expression of essential genes, and have now set about correcting this defect. Irreversibly inactivating this gene is not an option, so the researchers injected molecules called ‘short interfering RNAs’ (siRNAs) that directly inhibited Xist activity in early stage male SCNT embryos, which must maintain their single X chromosome in order to survive.

This treatment markedly boosted expression of X chromosomal genes relative to untreated controls, and although the direct effects of siRNA injection were fleeting, the benefits lingered. “The siRNA was effective for only 72 hours,” says Ogura, “but it had long-term effects not only on the birth rate but also on the health status of the offspring.” Indeed, his team achieved a success rate of nearly 20%—ten-fold better than previous efforts—and generated mouse pups that were apparently normal and healthy.

The implications for this improved efficiency extend beyond mass-produced mice, and this approach could represent a step toward improving the economics of cloning other species such as pigs and sheep, which are harder to genetically manipulate but nevertheless of considerable agricultural and scientific interest. “Our goal is to increase the birth rate of healthy cloned offspring not only in mice but also other mammals,” says Ogura, “and to understand the mechanisms by which the genome is drastically altered during the life cycle.”

The corresponding author for this highlight is based at the Bioresource Engineering Division, RIKEN BioResource Center

gro-pr | Research asia research news
Further information:

More articles from Life Sciences:

nachricht When fat cells change their colour
28.10.2016 | Albert-Ludwigs-Universität Freiburg im Breisgau

nachricht Aquaculture: Clear Water Thanks to Cork
28.10.2016 | Technologie Lizenz-Büro (TLB) der Baden-Württembergischen Hochschulen GmbH

All articles from Life Sciences >>>

The most recent press releases about innovation >>>

Die letzten 5 Focus-News des innovations-reports im Überblick:

Im Focus: Novel light sources made of 2D materials

Physicists from the University of Würzburg have designed a light source that emits photon pairs. Two-photon sources are particularly well suited for tap-proof data encryption. The experiment's key ingredients: a semiconductor crystal and some sticky tape.

So-called monolayers are at the heart of the research activities. These "super materials" (as the prestigious science magazine "Nature" puts it) have been...

Im Focus: Etching Microstructures with Lasers

Ultrafast lasers have introduced new possibilities in engraving ultrafine structures, and scientists are now also investigating how to use them to etch microstructures into thin glass. There are possible applications in analytics (lab on a chip) and especially in electronics and the consumer sector, where great interest has been shown.

This new method was born of a surprising phenomenon: irradiating glass in a particular way with an ultrafast laser has the effect of making the glass up to a...

Im Focus: Light-driven atomic rotations excite magnetic waves

Terahertz excitation of selected crystal vibrations leads to an effective magnetic field that drives coherent spin motion

Controlling functional properties by light is one of the grand goals in modern condensed matter physics and materials science. A new study now demonstrates how...

Im Focus: New 3-D wiring technique brings scalable quantum computers closer to reality

Researchers from the Institute for Quantum Computing (IQC) at the University of Waterloo led the development of a new extensible wiring technique capable of controlling superconducting quantum bits, representing a significant step towards to the realization of a scalable quantum computer.

"The quantum socket is a wiring method that uses three-dimensional wires based on spring-loaded pins to address individual qubits," said Jeremy Béjanin, a PhD...

Im Focus: Scientists develop a semiconductor nanocomposite material that moves in response to light

In a paper in Scientific Reports, a research team at Worcester Polytechnic Institute describes a novel light-activated phenomenon that could become the basis for applications as diverse as microscopic robotic grippers and more efficient solar cells.

A research team at Worcester Polytechnic Institute (WPI) has developed a revolutionary, light-activated semiconductor nanocomposite material that can be used...

All Focus news of the innovation-report >>>



Event News

#IC2S2: When Social Science meets Computer Science - GESIS will host the IC2S2 conference 2017

14.10.2016 | Event News

Agricultural Trade Developments and Potentials in Central Asia and the South Caucasus

14.10.2016 | Event News

World Health Summit – Day Three: A Call to Action

12.10.2016 | Event News

Latest News

Prototype device for measuring graphene-based electromagnetic radiation created

28.10.2016 | Power and Electrical Engineering

Gamma ray camera offers new view on ultra-high energy electrons in plasma

28.10.2016 | Physics and Astronomy

When fat cells change their colour

28.10.2016 | Life Sciences

More VideoLinks >>>