Worm Breeder's Gazette 16(3): 14 (June 1, 2000)
|1||Simon Fraser University|
We are developing a genetic map of Caenorhabditis briggsae in order to facilitate comparative studies with Caenorhabditis elegans. The two nematode species are morphologically similar but are approximately 25 - 40 million years apart. The comparison of the genetic maps of the two species should reveal how selective pressure constrains evolution of the linkage groups. For example, in C. elegans chromosomes there are regions of low and high rates of recombination (R. Johnsen Ph.D Thesis 1990, Simon Fraser University, Burnaby, Canada; S. Jones Ph.D. Thesis 1999 Cambridge Eng.). It has been postulated that highly conserved genes are more likely to be in regions of low recombination whereas rapidly evolving genes more likely reside in regions of high recombination. If this were true we would expect a similar gene distribution in C. briggsae. Our studies should also prove valuable for researchers who are comparing specific genes in in two nemotode species. As part of our investigations we want to identify which C. elegans genes correspond to each of the C. briggsae genes. So far we have identified 15 cby, 7 mip, 1 rot and 1 sml genes (the C. briggsae versions of dpy, unc, rol and sma respectively). Five of the cby genes, three of the mips and the rot are on the X-chromosome while the other 10 cbys, 4 mips and the sml gene map to autosomes. We have concluded that mip-1 is the C. briggsae version of unc-22 and cby-4 is dpy-1. We have also shown that mip-1, mip-3, mip-6, cby-7 and cby-8 are linked. In order to correlate the two genetic maps in an efficacious manner we request any help that the members of the worm community can afford us. Either by way of rescuing DNA or by helping with the identification of phenotypes that requires special knowledge or conditions to identify.