Retrotransposons: mobile and mutagenic from conception to death.

Mobile genetic elements feature prominently in mammalian genome evolution. Several transposition-competent retrotransposon families (L1, Alu, SVA) remain active in the human germ line, leading to pathogenesis as well as genome structural variation across the global population. High-throughput screening approaches have recently been developed to detect retrotransposon insertion polymorphisms. Evidence produced by these and other genome-scale technologies indicates an expanded role for retrotransposition in human biology, including somatic mobilisation in the developing embryo and in neural cells.