Induced Life: the Wonders of Stem Cells

Recently there was an amazing announcement in the world of stem cell research.  Scientists at Kyoto University in Japan managed to coax mouse derived stem cells to become viable eggs when transplanted into female mice.  The eggs were fertilised and embryos transplanted into foster mothers resulting in healthy, fertile offspring.  This is a major advancement in the science behind stem cell programming and fertility treatment.

The coolest part behind this work is understanding how to make stem cells develop into sex cells, or for that matter any other cell type.  This work comes out as Gurdon and Yamanaka receive the Nobel prize for work leading to the creation of stem cells from adult cells, a discovery that revolutionised science and our understanding of stem cells.  It’s a very complicated idea but I’ll try my best to explain it...

Gurdon and Yamanaka worked on the creation of what are called ‘induced pluripotent stem cells’ or iPS.  Pluripotent is the characteristic that stem cells have which means that they can go on to develop into any cell in your body (neurons, muscle, skin etc.).  The use of the word induced refers to the fact that these stem cells are created from a ‘mature’ adult cell that has already left its stem cell state.  The advantage of this is that it bypasses the ethics surrounding the use of embryonic stem cells derived from embryos.

So how do they do this?  

Very simply it is done by forcing the expression of genes which give stem cells their specific characteristics.  Amazingly, Yamanaka discovered that it only required expression of four key genes to create a stem cell.  These genes can be switched on by using a virus as a vector for carrying DNA sequences and inserting them into to the adult cell genome resulting in forced gene expression.

Picture taken from:http://www.rndsystems.com/cb_detail_objectname_cb09i2_induced_pluripotent_stem_cells.aspx

KLF4, SOX2, C-MyC, Nanog, Oct-3/4 and LIN-28 are genes that are forced to create iPS.

I know what you might be thinking; that’s seriously cool shit but how do you get from that to a fertile mouse conceived from a stem cell??

Well it’s easy (well not really) and simply involves nurturing stem cells with a cocktail of specific molecules that tell the stem cell what to do by activating certain genes at specific times.  Using this method scientists were able to produce a female sex cell from a stem cell which once fertilised was implanted into a donor mother and eventually was born as a healthy mouse.

You have to admit this kind of work is pretty amazing and Gurdon and co. much deserve the Nobel prize that they were awarded this year for without their groundbreaking work none of this science would be possible.