http://www.nature.com/nature/journal/v437/n7055/full/nature04063.html

Brief Communications Arising

Nature 437, E1-E2 (1 September 2005) | doi:10.1038/nature04063; Published online 31 August 2005

Plant genetics: RNA cache or genome trash?

Animesh Ray¹

Arising from: S. J. Lolle, J. L. Victor, J. M. Young & R. E. Pruitt Nature 434, 505–509 (2005); see also communication from Chaudhury; Lolle et al. reply.

According to classical mendelian genetics, individuals homozygous for an allele always breed true. Lolle et al.¹report a pattern of non-mendelian inheritance in the hothead(hth) mutant of Arabidopsis thaliana, in which a plant homozygous at a particular locus upon self-crossing produces progeny that are 10% heterozygous; they claim that this is the result of the emerging allele having been reintroduced into the chromosome from a cache of RNA inherited from a previous generation. Here I suggest that these results are equally compatible with a gene conversion that occurred through the use as a template of DNA fragments that were inherited from a previous generation and propagated in archival form in the meristem cells that generate the plant germ lines. This alternative model is compatible with several important observations by Lolle et al.¹.