Worm Breeder's Gazette 12(5): 17 (February 1, 1993)
These abstracts should not be cited in bibliographies. Material contained herein should be treated as personal communication and should be cited as such only with the consent of the author.
The long-term goal of this project is to provide a comprehensive set of chromosomal balancers covering the entire genome. Limited sets of lethal mutations ant sets of overlapping deficiencies and duplications are being generated to characterized new and existing balancers, and to make up a moderately high resolution "mapping kit" for the genome. At the start of this project in October 1991, about 50% of the genetic map was covered by proven balancers. Another 30% of the map included potentially useful rearrangements, ant no existing balancers were available for the remaining 20% (See Figure).
Since the project began, we have concentrated our efforts on three regions: the right arm of chromosome I, the left arm of chromosome IV, and the left arm of chromosome III. hInl (previously called hC1 ) has been used to recover EMS and gamma irradiation-induced lethals in the unc-75 - unc-54 region of chromosome I. Among the gamma-induced lethals are several putative deletions that are being characterized genetically (by mapping to visible and essential genes) and physically by PCR mapping. A new balancer generated for the left arm of chromosome m ( sC1 ) balances from the left eT1 breakpoint to w-45. EMS and gamma-induced lethals have been recovered using sC1 ,and these are now being analyzed. A second new balancer ( mC1 )has been generated for the left arm of chromosome IV, and it is being characterized in preparation for its use in mutant isolation. Screens are now underway for new balancers for the right end of chromosome V and the left end of the X chromosome.
Strains and information generated by the Toolkit project gradually will be made available to the C. elegans research community through the Caenorhabditis Genetics Center (CGC) and ACEDB. Complete strain descriptions and genetic mapping data for an new rearrangements will be sent to the CGC in electronic form as strains are characterized. For the moment we are handling distribution of new balancer stocks ourselves, since they are still in the process of characterization and we are developing a "balancer handbook" to distribute with such strains. We are collaborating with Jean Thierry-Mieg and Richard Durbin to display in ACEDB in an intuitive way all the information about available balancers. By picking a balancer in the genetic map display, the user will highlight the balanced regions of the genome, and see the various comments on a particular balancer's strengths and limitations.
We welcome information from you regarding balancers that you have used, in order to make the Toolkit information as comprehensive as possible and to save duplication of effort.