Worm Breeder's Gazette 17(1): 51 (October 1, 2001)
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.
Dept of Evolutionary Biology, Max Planck Institute for Developmental Biology, Tuebingen, Germany
In order to construct a genetic linkage map of Pristionchus pacificus, we generated a meiotic mapping panel of 46 animals. These animals were randomly picked in the F2 generation of a cross between a California phenotypic marker and Washington strain. Each SNP gives a certain segregation pattern with these 46 animals and the segregation patterns can then be fed into a computer program(Map Manager written by Stanford University) which then generates a genetic linkage map. We tested 131 SNPs on the mapping panel by SSCP analysis to construct a genetic linkage map of P.pacificus. Out of these 131 SNPs, 38 of them were ESTs and genes and the rest were BAC ends.
129 of the 131 SNPs assign to six linkage groups, the two remaining SNPs are unlinked to one another and to any other linkage group. We only considered markers that showed a recombination distance of less than 22 cM. The average genetic distance per linkage group is around 78 cM and the total genetic distance is 469 cM. The number of SNPs per chromosome and the distribution of the SNPs on a chromosome varies in accordance with genetic linkage maps of other organisms. We have selected two SNPs per chromosome for mapping P. pacificus vulva defective mutants. California derived mutant hermaphrodites were crossed to Washington males and 21 clones of mutant F2 animals were tested with the respective SNP markers for each chromosome by SSCP analysis. Unlinked markers are expected to be represented equally, whereas linked markers should give a predominant segregation of the Californian pattern. To demonstrate the utility of this method, we mapped Ppa-unc-1, the P. pacificus homolog of Cel -unc-22.