Studies on the X-chromosome of the nematode Panagrellus redivivus: EMS induced visible mutations

Young virgin males and females of the free-living nematode Panagrellus redivivus (deMan 1913) Goodey 1945 were mutagenized with 0.05 M ethyl methanesulphonate for 4 h. Twenty-four X-linked mutants were isolated, but only eight could be maintained as homozygotes due to severity of phenotype and mating inefficiency. The mutants define six complementation groups. The mutation frequency per locus was estimated to be 4.4 X 10(-4) following EMS treatment. An estimated 330 essential loci occur on the X-chromosome of P. redivivus.