On transplanting cells, not organs

This is fascinating. Here Susan Lim discussed the benefits of using iPS cells, and other stem cells in new forms of transplants.
These are adult cells taken from a patient's body and then turned back into undifferentiated, or pluripotent cells. Pluripotent cells can become any cell type in the body, which is really useful considering that adult stem cells eg. from the bone marrow, can't. Using embryonic stem cells, which is the alternative, is also fraught with ethical and moral dilemmas that go back to the question of whether an embryo is human; ie. when life begins. So this seems like a great way to go: however, consider this article in the Guardian that discusses a recent study where iPS cells were rejected in mice.
This is shocking because the iPS cells in the study came from the mouse itself, so in a way the mice were rejecting their own cells. The cells that came from iPS cells were implanted and then quickly destroyed by the mouse's immune system, whereas stem cells from embryos were not. The study is published in Nature.
This is probably down to abnormal gene expression, which has also been noticed in a variety of other cases. Cells derived from iPS cells have also been known to create tumours and a variety of problems, so they may not actually be the best way forwards.
Consider this article in the Guardian discussing the potential of reprogramming rather than transplanting tissue. Since these cells turn from one type to another, skipping the stem cell phase (ie. they re-differentiate), perhaps the ugly problems in iPS cell studies could be avoided.
This topic is very interesting, and research on stem cells and other forms of transplants and tissue repair are always emerging. The debate over transplanting organs and limbs vs. transplanting cells is also something to consider.

On genes controlling behaviour, or the burrow habits of mice

A recent article in Nature magazine discussed the burrow habits of mice. Scientists are studying these wild burrows, cross-breeding different species of mice.

They've unearthed some interesting stuff on links between behaviour and DNA, for example in studying why some species of mice dig fancy escape tunnels in their burrows whilst others stick with the humble hole-in-the-ground.

By studying the DNA of both wild oldfield mice(doesn't the name oldfield make you think of a mouse with a sergeant's cap and moustache waving around a rapier?) and deer mice, scientists have now been able to find out that burrowing behaviour is in the genes, not learned.

 

Deer mice

Oldfield Mice

So basically oldfield mice burrow these incredibly complex tunnels with escape routes when they dig holes in the ground. Researches have now found out that this behaviour is written in their genes, and not learned from watching parents/peers/acquaintances do the same. This burrowing behaviour, which wild deer mice do not exhibit, is interesting. Deer mice, on the other hand, dig simple holes in the ground which contrast 



with the vastly complicated structures oldfield mice build. Poor deer mice. (There's a diagram showing both forms of burrow at the end of this post).

This study gives an example of how closely genes can control and influence complicated behaviour are, as well as how complex the genes that determine such behaviour have to be.

The scientists who looked into this behaviour started out by studying burrow patterns of oldfield mice. They looked at the burrows created in a big box they filled with sand and saw the burrows were all very consistent; this suggests the burrows are genetically influenced. They then crossed deer mice with oldfield mice(yes, they can interbreed), and studied the burrow habits of the F1 generation. They then back-crossed this generation with original deer mice and again studied their burrowing habits.

 

The study follows Richard Dawkin's theory of the 'extended phenotype' (you may have read his book on the subject). Basically this is the effect a gene has on the environment of its particular organism. Mouse burrows is a perfect example of this; a gene affecting the environment. It will be interesting in the future to study other organisms(maybe beavers, or even dogs) to see how their behaviour and the environment around them is influenced by genes.

From Nature magazine. showing the burrow habits of the two species.



The BBC, the New York Times and Nat. Geographic have also reported on the research, if you want to read more about it/don't have a Nature magazine subscription.



On converting skin cells to neurons through protein suppression

So how simple is it to convert one type of cell to another type of cell?
Apparently, very simple.
All you have to do is suppress a single protein.
Scientists recently tried RNA molecules to repress a protein called PTB (not PBJ, unfortunately. That would have been cool). PTB is a protein that binds to RNA, and helps to regulate gene expression. Very low levels of this protein leads to certain genes being activated; these genes can convert skin cells to neurons. The genes allow trans-differentiation; this is when fully differentiated cells decide they're bored of who they are and convert to a totally different type of cell.

This information is drawn from the short piece in the Nature journal about this. It refers to a study done by researchers at University of California, San Diego and Wuhan University in Wuhan

This discovery is kind of a big deal. It would allow scientists who wanted to play around with neurons simply 'make' them from skin cells; they would no longer need to use undifferentiated stem cells to create neurons. I'm not a scientist myself, so I don't know how it could be used specifically, but certainly it sounds like it could have great far-reaching implications for researchers

Also, I can't help thinking this would be a great(or really, really bad) science-fiction movie plot.

Certainly it's a surprise to learn that converting differentiated skin cells to neurons is as simple as blocking production of a protein.