This is the text of a Correspondence by Richard Behringer of the University of Texas, published in the current issue of Nature (460, 324; 16 July 2009).
I was disappointed by the view expressed in your Editorial ‘The sharing principle’ (Nature 459, 752; 2009 – free to read online) that the mouse community does not share its strains. This is untrue. Most labs are very collegial, spending a considerable amount of time and effort on distributing their mouse strains. Although there are a few labs that withhold distribution, any community may contain such individuals. The fact that a mouse strain is not found in a repository does not mean that it is not being shared.
I was also puzzled by the conclusion of May’s CASIMIR workshop, noted in the Editorial, that “the sharing problem urgently needs resolution” with regard to international mouse gene-knockout projects. Such mutant alleles will mostly be archived as embryonic stem-cell lines. Readers should also realize that repositories cannot keep all their mouse strains live ‘on the shelf’: most strains are frozen. The cost for a user to have a strain thawed is thousands of dollars and it takes many months before the recovered mice become available. This is a big disadvantage for labs on tight budgets. With regard to funding agencies: in grant proposals to the US National Institutes of Health, for example, applicants are required to write a ‘resource-sharing plan’ that includes genetically modified mice.
It was suggested that sharing avoids duplication of effort. But it is essential that more than one group generates mutations in the same gene as a crosscheck. No two labs generate the same allele, and every geneticist knows that the expression of different alleles can lead to very distinct phenotypes.
Your claim that sharing mice “has never been easier” is questionable, considering all the paperwork, health certificates, veterinary screens, special serology screens, costs, time and logistics involved. This is quite different from uploading DNA sequences in the comfort of your office.
It would be great if funding agencies supplemented grants involving the generation of mouse strains to cover the costs of sending the strains to a repository. In these tough financial times, that seems unlikely.
Department of Genetics, University of Texas, M. D. Anderson Cancer Center, 1515 Holcombe Boulevard, Houston, Texas 77030, USA.