There was a huge fuss in the media this week about the first sperms to be made from human stem cells. It's not at all surprising that it can be done, of course. As pluripotent stem cells can be made to produce any kind of cells (with the right incentive), they can also produce eggs and sperms.

But why would one want to make artificial sperm when the natural thing is the one resource we have in zillion-fold excess over demand? There is only one reasonable answer -- people behind this are working towards making men redundant. In the future, one could easily make sure that only girls are conceived, and in order to keep fertilisation going, one would need to make sperms from stem cells. Easy as that. You can imagine the consequences (mainly positive, I happen to think) for yourself, or read this.

In a world without men, women will of course have to provide their own stimulation, as it were, and this is what this commentary is about. One of the authors used to live in our neighbourhood for a while, and I actually like her books, so I am sorry to see her imprint close down. I think the publishers have failed to read their crystal ball correctly ...

Ever wondered how Dr Who regenerates ? Well, ok, I know they just hire a different actor. But if and when the Doctor happens to get an arm amputated during his regeneration phase, it grows back, allegedly. Which is exactly what happens with a range of different animals, including salamanders.

Surprisingly, research in last week's issue of Nature shows that the axolotl does not use pluripotent stem cells to regenerate amputated limbs. Fluorescent labelling and tracking of cell fate reveals that the secret is in a sophisticated system of getting the right kinds of cells to the right places, and not in making cell pluripotent again.

Probably a disappointment for stem cell people, but intriguing nonetheless.

The original paper is here:

Cells keep a memory of their tissue origin during axolotl limb regeneration p60

By using an integrated GFP transgene to track the major limb tissues during limb regeneration in the salamander Ambystoma mexicanum (the axolotl), it has been possible to demonstrate that each limb tissue produces a different set of progenitors with restricted potential. Thus, the blastema—the collection of cells that regenerates the diverse tissues of the limb—is composed of a heterogeneous collection of restricted progenitor cells instead of dedifferentiated pluripotent cells, as previously thought.

Martin Kragl, Dunja Knapp, Eugen Nacu, Shahryar Khattak, Malcolm Maden, Hans Henning Epperlein & Elly M. Tanaka

doi:10.1038/nature08152


there is also an excellent News & Views piece about this research:

Developmental biology: A cellular view of regeneration p39
How the salamander regrows an entire limb after injury has flummoxed the wisest of scientists. A closer look at the cells involved in limb regeneration shows that remembering past origins may be crucial for this feat.

Alejandro Sánchez Alvarado

doi:10.1038/460039a

I'm surprised they didn't mention Dr Who, though.

I was amazed to learn from the Guardian last week that there are still children with radiation-related diseases in the Ukraine, a generation after the Chernobyl disaster. Something to consider before we solve our CO2 problems by switching everything to nuclear. Equally amazing the fact that they still get treated in Cuba, for free:

Revolutionary care: Castro's doctors give hope to the children of Chernobyl

It's very rare that I get artwork from my own production published along with my text, so I'm thrilled to see that my recent feature on farm animal genomics is illustrated with the photo of our local horse population, snapped maybe 100 metres from my doorstep. Note that the origin of different colours in horses is part of the subject matter of the piece, and the horses belonging to the local riding school display a nice range of colours.



I'm also pleased to have acquired a new outlet for my writing in German, in the shape of the medical magazine Trillium Report. My contribution is an essay on the possibility of higher cognitive function emerging in computer networks.

So there are 3 pieces in German this month:

Tycho Brahes Elemente, Nachrichten aus der Chemie p. 741
more about this

Genomik auf dem Bauernhof, Nachrichten aus der Chemie p. 779

Der Geist des Netzwerks Trillium Report 7, Nr 2, 57

Ever since I saw the Simpsons episode with the "big white guy who thinks he's the small black guy" I've been wondering whether this was really Michael Jackson doing the voiceover. Am glad to hear that it really was him:

Jackson's Simpsons episode to re-air as tribute

after all, who better to parody MJ than the man himself ?

Last week's cover of Nature confronts me with an uncomfortable choice: are science reporters cheerleaders or watchdogs? Well I don't like either of the metaphors, I would be more likely to describe my activity as that of building bridges, translating, communicating, interpreting ... Although there are occasions when I feel that certain parts of science are grotesquely underappreciated so I get out my pompoms and do a bit of cheerleading. More rarely, there are also occasions when I feel that scientists are going against the best interests of society, and I bare my teeth and let out some growling watchdog-like noises. But on the whole I am too busy building bridges across the Two-Cultures-Canyon to be bothered with either the cheering or the barking.

The reports and comments in Nature add to my increasing awareness -- which I talked about at the recent Copenhagen meeting and in my lectures in Germany -- that science reporting is changing quite drastically and rapidly, and we really need to think about how to ensure that the result we want to achieve, i.e. a reasonable level of public understanding of science, and public appreciation of the role science plays in our lives, doesn't fall overboard.

PS What I really don't understand is why the three cartoon characters on the cover had to be all male. Obviously they wanted to avoid the clichee of a female cheerleader, but a female watchdog would have looked really nice next to the male cheerleader ...

I had a very weird media experience on my way back from Germany. Having been cut off from electronic media since Thu afternoon, I arrived at Paris Fri morning and looked through the newspapers, both French and international ones. Only one of them (it may have been Le Figaro) had Michael Jackson's death on the front page.

I thought that was really weird -- surely, if he had died he would be on all the front pages, and it would be very difficult for one paper to get the story exclusively? Might they have been caught out by a hoax?

Unable to resolve this in situ, I took the Eurostar to London with a kind of Schrödinger's Jacko thought on my mind, wondering how he could be dead and alive at the same time. By the time I arrived at London, though, all the British papers whose early, Jacko-alive editions I had seen in Paris had changed their front pages, and he was all over the place. On the Guardian front page, poor old Farah Fawcett had to be dropped to make space for him.

So if future generations start asking where were you when you heard ... I'll have a more interesting story than on similar occasions (there are at least two catastrophic events which I heard about while sitting on the toilet, having walked past the radio and switched it on for the morning news!).

Anyhow. I can live with or without him and don't have strong feelings about his music one way or the other.

More importantly, I'm very excited that the first single from Shakira's new album is now online at her Myspace site. It's called "loba" (as in female wolf) and features her howling like a wolf :) Check it out.

What's the connection between bird migration, hydrogen storage materials, membrane protein structure, and quantum computation? Well, all these, and seven other topics are investigated at Oxford University with the help of Electron Spin Resonance (ESR) spectroscopy, thanks to the new(ish) interdisciplinary research centre CAESR. Read my feature in Oxford Today which should be freely accessible to all.

Also, a short piece on the bird migration research has appeared in German, in Chemie in unserer Zeit [PDF]

A round-up of pieces that appeared while I was travelling (and giving lectures) in Germany:

Fence protection progress Current Biology 19, No. 12, page R465 abstract and restricted access to pdf file
This one is about the electric fence protecting the Aberdare Reserve in Kenya -- originally built for rhinos and elephants, but now mainly protecting woods and mitigating the effects of climate change.

Spinout stories Chemistry & Industry No. 12, 22.6., page 29.
Review of the book Spin outs, by Graham Richards. A snippet:

In this little book, part memoir, part advice to future academic spin-out founders, he very briefly sketches his involvement with Oxford Molecular and with Oxford’s wider technology transfer activities, along with the briefest of mentions of related activities in the UK, such as the British Technology Group, later BTG.

Chemistry & Industry No. 12, 22.6., page 31
Review of the book Origin of life, by Piet Herdewijn and M. Volkan Kisakürek.
Snippet:

Maybe the most original and influential thinker on the origin of life over the last couple of decades is Günter Wächtershäuser, a patent attorney who came to the field as a hobby researcher drawing up new theories in his spare time. His chapter in the book is definitely worth reading, even if it leaves the reader with the frustrating thought that if Wächtershäuser can’t crack the conundrum, nobody can.

If mathematicians were to design trees, the result would probably look a bit like this sculpture:



which sits in the parks of Magdalen college, Oxford, and which I snapped from the River Cherwell on one of our canoe trips.