DNA methylation and Lamarckian inheritance

Jean Baptiste de Lamarck (1744-1829) maintained that characteristics that were acquired during an organism's lifetime are passed on to its offspring. This theory, known as Lamarckian inheritance, was later completely discredited. However, recent progress in epigenetics research suggests it needs to be reexamined in consideration of DNA methylation. In this article, I summarize our observations, which support Lamarckian inheritance. Initial experiments indicate that (1) artificially induced demethy-lation of rice genomic DNA results in heritable dwarfism, and (2) cold stress induces extensive demethy-lation in somatic cells of the maize root. Based on these results, I propose the hypothesis that traits that are acquired during plant growth are sometimes inherited by their progeny through persistent alteration of the DNA methylation status.