About Dicty Stock Center (DSC)

In the fall of 2002 the Dicty Stock Center was started at Columbia University in New York City as a repository for Dictyostelium discoideum and other cellular slime molds under the direction of Dr. Richard Kessin, and curated by Mr. Jakob Franke. Currently, more than 1,300 strains can be acquired from the stock center and this number is rapidly increasing. The strains available from the stock center are in the strain catalog on our website. Additionally, we have a rapidly expanding plasmid collection, the catalog of which can be accessed though the website. We plan to collect and make available all strains and mutants published in the scientific literature. Our web page is: http://dictybase.org/StockCenter/StockCenter.html.

The collection is being built by requesting published strains and plasmids. We also periodically remind investigators to send new mutants, natural isolates, and plasmids, once they have been published. Validation of the materials is mostly done by observable phenotypes, while mutants are also tested for drug-resistance markers and temperature sensitivity. Plasmids will be checked by performing one or two diagnostic restriction enzyme digests, and are stored both as DNA and transformed bacteria at -80°C. However, a large component of the quality control program will consist of feedback from the recipients of materials. Strains are stored at two different locations in liquid nitrogen, either as spores or as vegetative amoebae.

The stock center is also responsible for keeping the 'Franke Dictyostelium Reference Library' up to date. This database is a nearly complete collection of more than 8000 references specific to all aspects of the cellular slime molds, maintained in an EndNote database. The literature database can be downloaded here.

Below are some excerpts from: "A Concept Paper for a Strain and Plasmid Repository for the Dictyostelium Research Community", that formed the basis for the grant application.

The social amoeba Dictyostelium discoideum, an organism that is described on the NIH model organisms web page, is becoming increasingly useful as a research tool to ask fundamental questions in cell and developmental biology. The genome has been sequenced in Jena, Germany, Houston, TX, and Cambridge, UK, and is currently being assembled. Full-length cDNAs are being prepared and sequenced in Tsukuba, Japan. Although there had been substantial investment, it was decided that several facilities would further increase the efficiency of all laboratories working with this organism. One of these is a more developed website, and a second is a stock center where wild-type strains and thousands of mutants and plasmids could be preserved, tested, and distributed. These projects are synergistic and, therefore, our laboratory at Columbia submitted an application in parallel with Dr. Rex Chisholm at Northwestern University. Dr. Chisholm has had long experience providing access to information to the community, and we have had long experience with maintaining and distributing strains. These projects have now both been funded.

• What is the duration? The duration is indefinite, although not necessarily at Columbia. There are rules about succession in case the director and/or curator can no longer fill this function. There is an advisory board, consisting of veterans in the field and younger people who will be expected to take over when the current applicants retire. We expect that support will continue as long as there is a need for the facility. If the facility proves its worth, we would be willing to apply to NIH for funds other than the current RO1 grant. To this end, we keep records of the number of strains shipped and queries answered.


• How are the resources made available to the research community? The resources are available to the community through the web site managed by Dr. Rex Chisholm of Northwestern University (http://www.dictybase.org), and we coordinate closely with Dr. Chisholm in the selection of software to present information. Strains and plasmids will be sent to any person who requests them. There are no restrictions.


• What resources currently exist? No other stock center or repository existed prior to the Dicty Stock Center, and there were many losses of strains and confusion about wild-types and parental cell lines. Various species were being lost as highly trained taxonomists and collectors retired or died. A repository will prevent loss, reduce confusion about strain provenance, and makes the distribution of valuable mutants much more convenient and reliable. The stock center also serves as a central clearing house for quality assessment of mutants. People who receive strains are requested to confirm their validity.


• What is the size of the research community? The size of the community is roughly five hundred active scientists in 90 laboratories worldwide. Because of the cell biological and genetic possibilities of the organism, the community is growing. Dictyostelium is also widely used as a teaching tool. The community is organized and has a board of directors that is international in scope and seeks to make research on the organism as efficient and as cooperative as possible. The record of cooperation in this field is excellent.


• Who will benefit? All laboratories working on Dictyostelium will benefit, and new laboratories will have a resource for advice on growth and preservation of these important experimental tools.