Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:


World first: scientists succeed in cloning human embryos from eggs matured in the lab


Scientists in Belgium have discovered how to clone human embryos from eggs that have been matured in the laboratory. Their discovery should make it easier for scientists to create embryonic stem cell lines from cloned embryos and develop them to provide eggs and sperm for infertile couples, the 21st annual conference of the European Society of Human Reproduction and Embryology heard today (Monday 20 June).

Until now, scientists investigating human cloning for therapeutic purposes have been limited to using mature eggs (oocytes) that have reached the metaphase II stage (MII) at which ovulation and fertilisation occurs in humans. However, there are few human MII oocytes available for research because almost all that are retrieved from women seeking fertility treatment are used to treat the patient. Immature oocytes are not used routinely for treatment at present, and so any that are retrieved can be donated for research. These immature oocytes are arrested in the prophase I stage, before meiotic division is complete, when the enlarged nucleus is called the germinal vesicle (GV).

Bjorn Heindryckx, a PhD student at the Infertility Centre at Ghent University Hospital, Belgium, and his colleagues, matured GV oocytes in culture in the laboratory for 44 hours, after which time 85% of the GV oocytes had developed into MII oocytes. From each of these, they removed the nuclear apparatus, which contained the chromosomes that held all the genetic information. Using conventional ICSI techniques, they injected into the empty oocytes the nuclei taken from somatic cumulus1 cells (i.e. non-germ cells) of another person – a process known as non-autologous nuclear transfer. After time for nuclear re-programming the oocytes were artificially activated by incubation in a medium containing calcium ionophore, which enabled the injected nucleus to prepare for the first embryonic division.

Mr Heindryckx said: “Eighteen out of the 25 in vitro matured MII oocytes survived this nuclear transfer. Of these, 11 showed the formation of one pronucleus. In normal fertilisation the formation of male and female pronuclei is an important stage just before the maternal and paternal chromosomes start to pair up in preparation for the first cell division. In the case of these oocytes they had undergone a pseudo-fertilisation because the pronuclei were derived from whole foreign nuclei, each one with a complete set of homologous [matching] chromosomes, instead of from sperm and eggs which carry only one set of chromosomes each.”

Five oocytes divided to the two-cell stage, and of these, three continued to divide to the six- to ten-cell stage. One embryo continued to develop to the compacted stage, when the individual cells started to flatten and increase their contact with one another.

Mr Heindryckx said: “To our knowledge, this is the first report describing the development of cloned human embryos using in vitro matured oocytes and non-autologous transfer via a conventional method of nuclear transfer.

“Our final goal is to use human therapeutic cloning for infertility treatment by creating artificial eggs and sperm for patients who are infertile because of absence or premature loss of eggs or sperm. We would do this by isolating embryonic stem cell lines from cloned early embryos and driving these embryonic stem cells to develop into eggs and sperm in the laboratory.”

However, Mr Heindryckx warned that there was a long way to go and many problems to overcome before he and his colleagues could reach their goal.

“None of these early embryos developed to the blastocyst stage, and failure to do so could reveal some problems in gene activation, especially in cloned embryos. So, first we have to understand how to get cloned blastocysts of good quality from in vitro matured oocytes. This will be difficult because it is well known that embryonic development is compromised when in vitro matured oocytes are used, and in cloning technology the oocytes undergo intensive micromanipulation, which makes it even harder to develop good quality blastocysts. Once we have achieved this, the next step will be the isolation of the Inner Cell Mass (ICM) from which we can obtain embryonic stem cells.

“The availability of human oocytes is a major obstacle at the moment for research into therapeutic cloning. Therefore, we consider this research is important because it makes best use of more easily available biological material – in this case, immature oocytes.”

Emma Mason | alfa
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 >>>