Worm Breeder's Gazette 16(3): 14 (June 1, 2000)

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.

Correlating the C. elegans and C. briggsae genetic maps

B. Johnsen1, S. Gharib2, A. Ally1, K. Brown2, D. Baillie1, P. Sternberg2

1 Simon Fraser University
2 Caltech

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.