Charu Jain et al. (2007) International Worm Meeting "Identification of fungal virulence factors using C. elegans as a model host."

Charu Jain, Linsley Kelly, Brendan O'Brien, Reeta Prusty Rao, Samuel M. Politz

[International Worm Meeting, 2007]

Fungal pathogenesis is a significant medical problem. Fungi infect humans, plants and animals; because of their eukaryotic nature, it has been difficult to develop novel antifungal drugs which are not toxic to the host. It would be desirable to establish a model host-fungal pathogen system in order to identify virulence genes in the pathogen and immune response genes in the host. Although several fungal species have been shown to infect C. elegans, none of them is a well-characterized genetic model organism. On that basis we studied interaction between C. elegans as host and the yeast S. cerevisiae as pathogen. On mixed lawns of E. coli and S. cerevisiae, adult wild-type C. elegans showed a tail swelling similar to the deformed anal region (Dar) phenotype described for infection by the bacterium M. nematophilum. This phenotype is not induced by heat-killed yeast, and can be reversed by transferring worms to non-yeast containing plates. As proof of concept we have shown that yeast strains carrying a deletion in gene yap1 fail to induce the Dar phenotype. Yap1 encodes a fungal-specific transcription factor that has been implicated in pathogenesis by indirect evidence. YAP1 has two distinct functions: mediating responses to oxidative stress as well as pleiotropic drug resistance. To investigate which of these is important for producing the Dar phenotype, we tested a yeast strain carrying a deletion in the sod1 superoxide dismutase gene. Like yap1, the sod-1 mutant did not produce the Dar phenotype. In contrast, yeast mutants pdr1 and pdr15, which are involved in pleiotropic drug resistance, and osr5, which is involved in osmotic stress, produced a Dar phenotype similar to wild type, suggesting that the ability to respond to oxidative stress is specifically required for yeast to induce the Dar phenotype. Our working hypothesis is that worms produce reactive oxygen species (ROS) which yeast must counteract in order to be able to induce the Dar phenotype. We are currently testing candidate C. elegans mutants for increased sensitivity or resistance to Dar induction by yeast.

Edgley ML et al. (1991) International C. elegans Meeting "Caenorhabditis genetics center."

Riddle DL, Edgley ML, Estevez AOZ

[International C. elegans Meeting, 1991]

The CGC has been in operation for 12 years, supplying Caenorhabditis strains and information to researchers. It is responsible for coordination of C. elegans genetic nomenclature, and acts as the central clearing house for naming strains, genes and alleles. Information distributed includes the genetic map, genetic map data, strain information, a bibliography of 1300 research articles and book chapters, and the C. elegans research newsletter, the Worm Breeder's Gazette, which is distributed to 450 subscribers worldwide. A collection of 1550 strains has been established, representing 30 wildtype isolates of C. elegans, wild-type strains of C. briggsae, C. remanei and C. vulgariensis, as well as alleles of 773 mutant genes and 254 chromosome rearrangements. Stocks are stored permanently in liquid nitrogen. Approximately 1350 different strains have been distributed to research laboratories in 7800 separate mailings. Investigators in 210 laboratories in 21 countries have either received strains from the CGC or contributed strains to the CGC collection. The current version of the C. elegans genetic map includes 26 pages, and contains 920 genes and 320 rearrangements. It is produced using the computer drawing program Designer (Micrografx, Inc., Richardson TX), which runs under Microsoft Windows on IBM-compatible microcomputers. The map is published biannually in Genetic Maps (S.J. O'Brien, editor; Cold Spring Harbor Laboratory) and semi-annually in the Worm Breeder's Gazette. Caenorhabditis strains and information are available upon request. All strain, bibliographic and genetic information is maintained on a microcomputer database system, and the various files are available as printouts or data on diskette. Operation of the CGC will be transferred to other investigators at the end of the current CGC contract (September 29,1992). One possible plan emerged at the last C. elegans meeting, in which Bob Herman will assume responsibility for the strain collection, and Jonathan Hodgkin will assume responsibility for the genetic map. Plans for continuation of other CGC services remain to be made. New developments in the use of computers to integrate all information on the worm will enhance the usefulness of data collected by the CGC (see Thierry-Mieg, Durbin, Schatz and Ward, this meeting). The CGC is supported by the NIH National Center for Research Resources.