Judging/Variance/UChicago

Team Request
Dear iGEM headquarters:

We would like to use two news types of S. cerevisae expression vectors, pRS314 and pRS316 modified to meet biobrick standards. These are essentially empty vectors with ampicillin resistance for selection in E. coli and tryptophan and uracil (respectively) in S. cerevisiae. The plasmid maps can be found at

https://www.lablife.org/ct?f=c&a=showvecinfo&vectorid=3297 https://www.lablife.org/ct?f=c&a=showvecinfo&vectorid=3299.

We are in the process of modifying these plasmids to fit biobrick standards, including removing extra XbeI, SpeI and PstI sites.

Our second request is for a new standard of yeast expression derived from Longtine, et al.” Additional Modules for Versatile and Economical PCR-based Gene Deletion and Modification in Saccharomyces cerevisiae.” Yeast 14, 953–961 (1998). The modules described in the paper allow for easy deletion, replacement, modification or over-expression of a gene of interest without use of a plasmid. We have been using pFA6a-GFP(S65T)-kanMX6 and pFA6a-GFP(S56T)-His3MX6. Using PCR, we amplify our module of interest with tails on either end that correspond to the gene region we wish to exploit. To integrate these fragments into the S. cerevisiae genome we simply transform with our amplified product. We hope to submit these plasmids with the Longtine modules, as well as our two biobrick-compatible cerevisiae plasmids to the registry. Please let us know whether this will be feasible. Thank you! Nora Yucel University of Chicago iGEM team

Judges' Response
Hi Nora,

Thanks for your email!

In the first case involving yeast expression vectors you do not appear to be proposing a new technical standards but rather are making existing yeast vectors compatible with one or more of the existing biobricks assemble standards, as per BBF RFC #29 (http://openwetware.org/wiki/The_BioBricks_Foundation:RFC). If correct, and so long as your work is well documented, this aspect of your project would not require a variance.

In the second case involving marker supported chromosomal integration in yeast I would (speaking for myself) need to learn or hear more about why the approach you are taking should define a new technical standard. What is being standardized? The process of integration and expression in yeast? What are the limits of the standard? E.g., could you combine multiple BioBrick parts into a yeast chromosome via this method. If you go down this path you should draft a new BBF RFC following the instructions in BBF RFC #0.

With apologies that I may have misunderstood some or all aspects of your email, but I wanted to respond quickly.

All best and thanks again! Drew