An Alternate Hypothesis to Explain the High Frequency of “Revertants” in Hothead Mutants in Arabidopsis

Abstract

Lolle et al. reported a high frequency of genomic changes in Arabidopsis plants carrying the hothead mutation and proposed that the changes observed were the result of a gene correction system mediated by a hypothetical RNA cache. Here, we propose a very different hypothesis to explain the data reported by Lolle et al. Our hypothesis is based on a relatively straightforward developmental aberration in which maternal cells (“Legacy cells”) fuse with the developing embryo, resulting in a chimera, which could then give rise to the aberrant genetic segregations reported by Lolle et al.

Hothead - legacy cell - non-Mendelian.

References

• 1 Chaudhury A.. Plant genetics: hothead healer and extragenomic information.  Nature. (2005);  437 E1-E2
• 2 Comai L., Cartwright R. A.. A toxic mutator and selection alternative to the non-Mendelian RNA cache hypothesis for hothead reversion.  Plant Cell. (2005);  17 2856-2858
• 3 Grossniklaus U., Schneitz K.. The molecular and genetic basis of ovule and megagametophyte development.  Seminars in Cell and Developmental Biology. (1998);  9 227-238
• 4 Krolikowski K. A., Victor J. L., Wagler T. N., Lolle S. J., Pruitt R. E.. Isolation and characterization of the Arabidopsis organ fusion gene HOTHEAD.  The Plant Journal. (2003);  35 501-511
• 5 Kurdyukov S., Faust A., Trenkamp S., Bar S., Franke R., Efremova N., Tietjen K., Schreiber L., Saedler H., Yephremov A.. Genetic and biochemical evidence for involvement of HOTHEAD in the biosynthesis of long-chain alpha-, omega-dicarboxylic fatty acids and formation of extracellular matrix.  Planta. (2006);  1-15
• 6 Lolle S. J., Victor J. L., Young J. M., Pruitt R. E.. Genome-wide non-mendelian inheritance of extra-genomic information in Arabidopsis.  Nature. 2005;  434 505-509
• 7 Ray A.. Plant genetics: RNA cache or genome trash?.  Nature. (2005);  437 E1-E2

Editor: F. Salamini