Researchers led by Professor Karim Nayernia at Newcastle University and the NorthEast England Stem Cell Institute (NESCI) have developed a new technique which has made the creation of human sperm possible in the laboratory.
The work is published today (8th July 2009) in the academic journal Stem Cells and Development.
The NorthEast England Stem Cell Institute (NESCI) is a collaboration between Newcastle and Durham Universities, Newcastle NHS Foundation Trust and other partners.
Professor Nayernia says: "This is an important development as it will allow researchers to study in detail how sperm forms and lead to a better understanding of infertility in men – why it happens and what is causing it. This understanding could help us develop new ways to help couples suffering infertility so they can have a child which is genetically their own."
"It will also allow scientists to study how cells involved in reproduction are affected by toxins, for example, why young boys with leukaemia who undergo chemotherapy can become infertile for life – and possibly lead us to a solution."
The team also believe that studying the process of forming sperm could lead to a better understanding of how genetic diseases are passed on.
In the technique developed at Newcastle, stem cells with XY chromosomes (male) were developed into germline stem cells which were then prompted to complete meiosis - cell division with halving of the chromosome set. These were shown to produce fully mature, sperm called scientifically, In Vitro Derived sperm (IVD sperm).
In contrast, stem cells with XX chromosomes (female) were prompted to form early stage sperm, spermatagonia, but did not progress further. This demonstrates to researchers that the genes on a Y chromosome are essential for meiosis and for sperm maturation.
The IVD sperm will not and cannot be used for fertility treatment. As well as being prohibited by UK law, the research team say fertilization of human eggs and implantation of embryos would hold no scientific merit for them as they want to study the process as a model for research.
"While we can understand that some people may have concerns, this does not mean that humans can be produced 'in a dish' and we have no intention of doing this. This work is a way of investigating why some people are infertile and the reasons behind it. If we have a better understanding of what's going on it could lead to new ways of treating infertility," adds Professor Nayernia.
The Newcastle University team have developed a method for establishing early stage sperm from human embryonic stem cells in the laboratory.
The embryonic stem cells were cultured in a new medium containing vitamin A derivative (retinoic acid), in a new technique established by the team. Based on this technique, the cells differentiated into germline stem cells.
These expressed a protein which was stained with a green fluorescent marker and they were separated out by FACSTM (Fluorescence-activated cell sorting) using a laser.
After further differentiation, these in vitro derived germline stem cells expressed markers which are specific to primordial germ cells, spermatogonial stem cells, meiotic (spermatocytes) and post meiotic germ cells (spermatids and sperm).
These results indicated maturation of the primordial germ cells to haploid male gametes – called IVD sperm - characterised by containing half a chromosome set (23 chromosomes).
Karen Bidewell | EurekAlert!
Could this protein protect people against coronary artery disease?
17.11.2017 | University of North Carolina Health Care
Microbial resident enables beetles to feed on a leafy diet
17.11.2017 | Max-Planck-Institut für chemische Ökologie
The formation of stars in distant galaxies is still largely unexplored. For the first time, astron-omers at the University of Geneva have now been able to closely observe a star system six billion light-years away. In doing so, they are confirming earlier simulations made by the University of Zurich. One special effect is made possible by the multiple reflections of images that run through the cosmos like a snake.
Today, astronomers have a pretty accurate idea of how stars were formed in the recent cosmic past. But do these laws also apply to older galaxies? For around a...
Just because someone is smart and well-motivated doesn't mean he or she can learn the visual skills needed to excel at tasks like matching fingerprints, interpreting medical X-rays, keeping track of aircraft on radar displays or forensic face matching.
That is the implication of a new study which shows for the first time that there is a broad range of differences in people's visual ability and that these...
Computer Tomography (CT) is a standard procedure in hospitals, but so far, the technology has not been suitable for imaging extremely small objects. In PNAS, a team from the Technical University of Munich (TUM) describes a Nano-CT device that creates three-dimensional x-ray images at resolutions up to 100 nanometers. The first test application: Together with colleagues from the University of Kassel and Helmholtz-Zentrum Geesthacht the researchers analyzed the locomotory system of a velvet worm.
During a CT analysis, the object under investigation is x-rayed and a detector measures the respective amount of radiation absorbed from various angles....
The quantum world is fragile; error correction codes are needed to protect the information stored in a quantum object from the deteriorating effects of noise. Quantum physicists in Innsbruck have developed a protocol to pass quantum information between differently encoded building blocks of a future quantum computer, such as processors and memories. Scientists may use this protocol in the future to build a data bus for quantum computers. The researchers have published their work in the journal Nature Communications.
Future quantum computers will be able to solve problems where conventional computers fail today. We are still far away from any large-scale implementation,...
Pillared graphene would transfer heat better if the theoretical material had a few asymmetric junctions that caused wrinkles, according to Rice University...
15.11.2017 | Event News
15.11.2017 | Event News
30.10.2017 | Event News
17.11.2017 | Physics and Astronomy
17.11.2017 | Health and Medicine
17.11.2017 | Studies and Analyses