Research conducted by plant biologists at the University of California, Davis brings scientists closer to breeding plants with genes from one parent.
The work is based on a discovery previously made by the late Simon Chan and colleagues over a decade ago when they serendipitously discovered a way to eliminate the genetic contribution from one parent while breeding Arabidopsis. They modified a protein called CENH3 which is found in the centromere of a chromosome. Crossing wild-type Arabidopsis with plants with modified CENH3, they got plants with half the normal number of chromosomes, and the part of the genome from one parent plant had been eliminated to create a haploid plant.
However, replicating Chan's work has been fruitless, according to Professor Luca Comai, UC Davis Department of Plant Biology and Genome Center, who is senior author on the new paper. Mohan Marimuthu, a researcher at the UC Davis Genome Center and Department of Plant Biology, with Comai, Maruthachalam (now at the Indian Institute of Science Education and Research, Kerala), and colleagues found that when CENH3 protein is altered, it is removed from the DNA in the egg before fertilization, weakening the centromere.
According to Comai, the CENH3-depleted centromeres contributed by the egg fail to compete with the CENH3-rich ones contributed by the sperm, and the female genome is eliminated. This new knowledge would make it easier to induce haploids in plants.
(Source: Crop Biotech Update, International Service for Acquisition of Agri-Biotech Applications. www.isaaa.org)
