Plant genetics: RNA cache or genome trash?
According to classical mendelian genetics, individuals homozygous for an allele always breed true. Lolle et al. report 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..
Ray
Animesh
A
Keck Graduate Institute, Claremont, California 91711, USA. aray@kgi.edu
D000483:Alleles; D017360:Arabidopsis / Q000166:cytology / Q000235:genetics*; D029681:Arabidopsis Proteins / Q000235:genetics; D005785:Gene Conversion / Q000235:genetics*; D017343:Genes, Plant / Q000235:genetics; D018745:Genome, Plant; D005854:Germ Cells / Q000378:metabolism; D006579:Heterozygote; D006720:Homozygote; D018519:Meristem / Q000166:cytology / Q000378:metabolism; D008957:Models, Genetic; D009928:Organ Specificity; D018749:RNA, Plant / Q000235:genetics*; D013698:Templates, Genetic
D029681:Arabidopsis Proteins; D018749:RNA, Plant; C503530:hothead protein, Arabidopsis