Genes Dev. doi:10.1101/gad.1893210 (2010)

Transposons, or 'jumping genes', move around genomes and can disrupt normal gene function. As a result, many organisms add methyl groups to their transposons to silence them. But how does a cell determine where a transposon ends and a protein-coding gene begins?

Eric Selker at the University of Oregon in Eugene and his team tackled this question in the fungus Neurospora crassa. When they disrupted a gene called dmm1, methylation spread beyond transposon borders and into neighbouring genes. The resulting mutants grew more slowly.

The DMM1 protein interacts with another protein, DMM2, and dmm2 mutants also had excess methylation. The results suggest that DMM1 and DMM2 act together in a complex that protects genes residing near transposons.