Evidence for the lack of mismatch-repair directed antirecombination during mouse meiosis.
Meiotic recombination was studied in DNA mismatch repair (MMR)-deficient mice using a strain carrying a Pms2 knockout mutation. Using single-sperm typing, recombination was analyzed over five intervals on four chromosomes in four Pms2 -/- animals. A total of 1936 meioses were studied and compared to 1848 meioses from three Pms2 +/+ controls. A smaller study was carried out on a single interval in each of two chromosomes in an MMR-deficient mouse homozygous for the Msh2 knockout mutation. A total of 792 meioses were examined in the Msh2 -/- and 880 meioses in the Msh2 +/+ animal. Recombination fractions were not significantly different in either of the MMR-deficient mouse strains when compared to MMR-proficient controls. Our results appear to conflict with mouse embryonic stem (ES) cell gene-targeting experiments where MMR plays a major role in determining the efficiency of homologous recombination between nonidentical sequences. A number of possibilities could explain the apparent lack of a significant effect on meiosis.
Molecular Biology Program, University of Southern California, 835 West 37th St., Los Angeles, CA 90089-1340, USA.
J
J
Qin
S
S
Baker
H
H
Te Riele
R M
RM
Liskay
N
N
Arnheim
D000251:Adenosine Triphosphatases / Q000172:deficiency / Q000235:genetics; D000818:Animals; D020137:Base Pair Mismatch; D001483:Base Sequence; D017931:DNA Primers; D004260:DNA Repair / Q000235:genetics; D045643:DNA Repair Enzymes; D004268:DNA-Binding Proteins / Q000172:deficiency / Q000235:genetics; D008297:Male; D008540:Meiosis / Q000235:genetics*; D051379:Mice; D018345:Mice, Knockout / Q000235:genetics*; D000070976:Mismatch Repair Endonuclease PMS2; D051718:MutS Homolog 2 Protein; D011518:Proto-Oncogene Proteins / Q000172:deficiency / Q000235:genetics; D011995:Recombination, Genetic; D013094:Spermatozoa / Q000002:abnormalities
D017931:DNA Primers; D004268:DNA-Binding Proteins; D011518:Proto-Oncogene Proteins; D000251:Adenosine Triphosphatases; C499533:Pms2 protein, mouse; D000070976:Mismatch Repair Endonuclease PMS2; C497173:Msh2 protein, mouse; D051718:MutS Homolog 2 Protein; D045643:DNA Repair Enzymes