NZ science breakthrough
Microscope images - these bovine induced pluripotent stem cell (iPSC)-like) cells express pluripotency markers TRA 1-81 (left) and SSEA-4 (right).
6 September 2011
NZ science breakthrough: first virus-free pluripotent stem cells in cattle
International science publication PloS ONE, the world's largest scientific journal, has published a research discovery by AgResearch scientists into cattle stem cells.
Induced pluripotent stem
cells (iPSCs) are capable of turning into any cell type in
the body, an ability referred to as 'pluripotency'. Unlike
embryonic stem cells, which are also pluripotent, iPSCs do
not require destruction of an early embryo but can be
derived from almost any cell in the body.
Dr Ben Huang,
AgResearch Scientist and lead author of the study,
attributes the success to a novel culture medium. "This
medium promotes pluripotency by inhibiting different cell
signalling pathways. Using signal inhibition, we induced
stem cell markers in bovine skin cells. We then coaxed them
into forming mature tissues after transplantation into
mice", explains Dr Huang. "Importantly, the culture
conditions were completely chemically defined and free of
potentially pathogenic components, such as feeder cells or
serum," he said. Unlike iPSCs in other species, the
bovine cells did not require viruses to carry
pluripotency-inducing genes into cells. For their virus-free
approach, AgResearch scientists simply incubated skin cells
in plasmid DNA encoding the pluripotency factors and
watched the cells reprogramme back into an embryonic stem
cell-like state. This delivery route is safer than viruses,
which can trigger the immune system and cause tumours.
Plasmids are also easy-to-use and cheap, eliminating the
need for specialised biohazard containment
facilities. The
research was funded by the New Zealand Foundation for
Research, Science and Technology (the Ministry of Science
and Innovation) and
AgResearch.
The science team at
Ruakura, led by Dr Björn Oback, has produced the first
virus-free pluripotent stem cell-like cells in
cattle
Dr Oback predicts that this discovery and the
convergence of reproductive and stem cell technology will
unlock a new realm of practical possibilities for
agriculture. "This breakthrough shows that by firmly
focussing on farm animals, with cattle as a model system, we
can leverage New Zealand's distinct strengths and make
important scientific contributions to this field of
research," said Dr Oback.
New Zealand will ultimately benefit from
this advance in stem cell technologies. Future agricultural
applications include the ability to generate animals whose
sperm are made from iPSCs. In such animals could be used to
effectively capture and multiply elite genetics, taking
genomic selection from the whole animal to the cellular
level, accelerating breeding and genetic gain.
ends