Beschreibung:
<jats:title>Significance</jats:title>
<jats:p>We present experimental evidence showing that meiosis is an important source of germline mutations. Because sites of meiotic recombination experience recurrent double-strand breaks at hotspots, recombination has been previously suspected to be mutagenic. Yet inferences made from sequence comparisons have not found strong evidence for a mutagenic effect of recombination. Here, we directly sequenced a large number of single sperm DNA molecules and found more new mutations in molecules with a crossover than in molecules without a recombination event. We also observed that GC alleles are transmitted more often than AT alleles at polymorphic sites. Our data demonstrate that both mutagenesis and biased transmission occur during crossing over in meiosis and are important modifiers of the sequence content at recombination hotspots.</jats:p>