Frequent germline mutations and somatic repeat instability in DNA mismatch-repair-deficient Caenorhabditis elegans.
Mismatch-repair-deficient mutants were initially recognized as mutation-prone derivatives of bacteria, and later mismatch repair deficiency was found to predispose humans to colon cancers (HNPCC). We generated mismatch-repair-deficient Caenorhabditis elegans by deleting the msh-6 gene and analyzed the fidelity of transmission of genetic information to subsequent generations. msh-6-defective animals show an elevated level of spontaneous mutants in both the male and female germline; also repeated DNA tracts are unstable. To monitor DNA repeat instability in somatic tissue, we developed a sensitive system, making use of heat-shock promoter-driven lacZ transgenes, but with a repeat that puts this reporter gene out of frame. In genetic msh-6-deficient animals lacZ+ patches are observed as a result of somatic repeat instability. RNA interference by feeding wild-type animals dsRNA homologous to msh-2 or msh-6 also resulted in somatic DNA instability, as well as in germline mutagenesis, indicating that one can use C. elegans as a model system to discover genes involved in maintaining DNA stability by large-scale RNAi screens.
Tijsterman
Marcel
M
Hubrecht Laboratory, Centre for Biomedical Genetics, 3584 CT, Utrecht, The Netherlands.
Pothof
Joris
J
Plasterk
Ronald H A
RH
D000595:Amino Acid Sequence; D000818:Animals; D030801:Animals, Genetically Modified; D020137:Base Pair Mismatch; D017173:Caenorhabditis elegans / Q000235:genetics*; D029742:Caenorhabditis elegans Proteins / Q000235:genetics; D004260:DNA Repair / Q000235:genetics*; D004268:DNA-Binding Proteins; D005260:Female; D018095:Germ-Line Mutation; D008297:Male; D018895:Microsatellite Repeats; D008969:Molecular Sequence Data; D051719:MutS DNA Mismatch-Binding Protein; D051718:MutS Homolog 2 Protein; D011518:Proto-Oncogene Proteins; D034622:RNA Interference; D017422:Sequence Analysis, DNA
D029742:Caenorhabditis elegans Proteins; D004268:DNA-Binding Proteins; D011518:Proto-Oncogene Proteins; C450145:msh-2 protein, C elegans; D051719:MutS DNA Mismatch-Binding Protein; D051718:MutS Homolog 2 Protein