Haploid plants produced by centromere-mediated genome elimination

When plants go halves: haploids made easy Haploid plants, inheriting chromosomes from one parent only, have important advantages in genetic research but also crucially in plant breeding, where they are used to create instant homozygous diploid lines, circumventing many generations of inbreeding. Maruthachalam Ravi and Simon Chan have now developed a simple method for producing haploid Arabidopsis thaliana via seeds that can be readily extended to crop plants. Previously haploid production involved tissue culture or genome elimination in wide crosses, and many species are intractable to these methods. The new technique involves engineering a single protein, the centromere-specific histone CENH3, to create strains whose genome is eliminated from the zygote after crossing to wild type. This generates haploid plants with chromosomes from the wild-type parent only. CENH3 plays a universal role at eukaryote centromeres, so in principle this should be transferable to all plant species.