An epic struggle is taking place between a rapidly growing Dublin-based pharmaceutical firm, Elan, and an influential non-profit medical research organisation, the Mayo Foundation. At stake in this epic struggle: who owns a transgenic mouse.In October a jury in San Francisco will make a decision in the bizarre and complex court case. Teams of elite lawyers will have spent weeks studying and arguing over crates of laboratory notes, letters and e-mails concerning a mouse named  TG2576. It might as well be called Mighty Mouse: pound for pound, its breed is probably the most expensive in the world. A breeding trio of males is said to be worth up to $1-million. TG2576, also known as the Hsiao Mouse after its creator, Karen Hsiao-Ashe, is precious because it is demented. It is designed to contract Alzheimer’s disease. It is known as a ?transgenic? mouse, and its cells produce a mutant human protein that has been implicated in Alzheimer’s disease. When the mice are 10 months old they begin to get senile, to forget things they were just taught. The value of TG2576 is that it?s a gateway to Alzheimers,  of huge value  to the researchers trying to find a cure, and to the shareholders of companies trying to get cures to market. The Minnesota-based Mayo Foundation, which provides Hsiao mice at cost to academic researchers around the world, and sells them to commercial companies, won’t say how much the private sector is prepared to pay for the rodents. But Mayo neuroscientist Steven Younkin, one of Hsaio’s collaborators, says: ?Let’s take a figure of, say, $2-million. Do you think any firm working seriously on a treatment with a potential annual market of $150-billion is going to stop for $2-million? It’s a drop in the bucket.?Elan?s share price has shot up since it began trials of a vaccine that may prevent or treat Alzheimer’s. The vaccine was developed with the help of another, secret strain of Alzheimer’s mouse that Elan created. Unlike the Hsiao mouse, Elan’s mouse is not for sale. But keeping its mouse under lock and key is not enough for Elan: it wants to prevent distribution of the Hsiao mouse as well, accusing Mayo of infringing its patents on a third strain of mouse. Hence the court battle. Younkin, who has been ordered to make research notes and data available for the case, thinks Elan’s strategy is ‘Let’s make sure we make all the money we possibly can, and if it slows down research, that’s too bad. We’ve got our shareholders to worry about.? This is bad for science as a whole, say Younkin and many who agree with him.

?At conferences people are swapping their mice around, arranging marriages between mice,? says Dr Denis Alexander, who has helped design mice to investigate the human immune system at the Babraham Institute outside Cambridge in England. ?You can’t even measure how much slower research would be if it wasn’t for the transgenic mice. The genome project would be throwing out all these genes and you wouldn’t be able to do experiments. To do it the traditional way, you’d be talking about hundreds of years of work. If we didn’t have these mice we’d still be in the immunological Dark Ages.?