The passionate life of Simon Chan

Simon was born in Auckland, New Zealand. He graduated with a degree in biochemistry from the University of Auckland and earned a Ph.D. from UCSF, where he studied yeast telomeres under the guidance of Nobel laureate Elizabeth Blackburn. He did his postdoctoral research in the laboratory of Steve Jacobsen at UCLA working on RNA-directed DNA methylation and gene silencing. In 2006, Simon joined the faculty in the Department of Plant Biology at UC Davis. At that time, Simon took his passion for chromosomal biology and epigenetics into a new area: centromeric function and inheritance.At UC Davis, Simon and his postdoctoral associate, Ravi Maruthlalacham, labored for three years studying the function of centromeric histone H3 (CENH3). Their approach was to complement a nullimorphic cenh3 mutant of Arabidopsis with genes encoding versions of CENH3 with varying degrees of alteration. They found that if a plant with an altered CENH3 was crossed to the wild type, many F1s were sterile. Chromosome mounts from these individuals revealed five chromosomes instead of ten, the expected diploid number. The hypothesis explaining these results had far-reaching implications: centromeres organized by a modified CENH3 were stable in crosses between similarly modified plants. However, when confronted in the zygote with centromeres determined by wild-type CENH3 the centromeres with the altered CENH3 lost out, causing the loss of the connected chromosomes. The resulting haploids could be easily converted to di-haploids (doubled haploids), enabling the establishment of pure inbreds in a single generation. This discovery, published in Nature in 2010 [2], has basic and applied importance. For example, in a 2011 Science article [3], the Chan lab collaborated with Raphael Mercier and Imran Siddiqi to demonstrate the production of clonal plants through seeds in a process mimicking apomixis. This was done by crossing the haploid inducer line with a plant that bypassed meiotic recombination and re