Loss of heterozygosity in Phytophthora capsici after N-ethyl-nitrosourea mutagenesis.
Loss of heterozygosity (LOH) occurs in a variety of diploid organisms after chemical mutagenesis and was observed in the vegetable pathogen Phytophthora capsici after N-ethyl-nitrosourea (ENU) mutagenesis at three loci during reverse genetic screening. Our objectives were to determine (i) the frequency of LOH among mutants, (ii) the directionality of the LOH events and (iii) the length of the genomic tracts exhibiting LOH. Of the 1152 ENU mutants screened, LOH was most frequent at locus 3 (99 ENU mutants), with locus 1 (10 ENU mutants) and locus 2 (9 ENU mutants) undergoing LOH at similar frequencies. LOH was bidirectional for all three loci, with locus 3 mutants biased toward one haplotype. Analysis of upstream and downstream heterozygosity indicates that the LOH events spanned up to at least 4.6 kb. The implications of mitotic recombination and LOH for reverse genetics and natural variation in Phytophthora are discussed.
Hulvey
Jon
J
Genome Science and Technology Graduate Program, University of Tennessee, Knoxville, Tennessee, USA. jhulvey@utk.edu
Young
Jacque
J
Finley
Ledare
L
Lamour
Kurt
K
D000477:Alkylating Agents / Q000633:toxicity*; D005038:Ethylnitrosourea / Q000633:toxicity*; D019656:Loss of Heterozygosity; D016296:Mutagenesis; D009153:Mutagens / Q000633:toxicity*; D010838:Phytophthora / Q000187:drug effects / Q000235:genetics*; D017354:Point Mutation; D016133:Polymerase Chain Reaction / Q000379:methods; D011995:Recombination, Genetic; D044366:Transition Temperature
D000477:Alkylating Agents; D009153:Mutagens; D005038:Ethylnitrosourea