Successful genome transfer to the next generation is a fundamental issue to all living things and thus, “Reproduction” field is the great beauty of biology to understand living things, environment and their interactions.
Our laboratory is interested in understanding reproduction process, especially from flowering until seed formation. During this time, plant-specific gametogenesis and embryogenesis occur before and after fertilization, respectively. Unlike animals, plants do not set aside the gamete cells. One of the 2n sporophytic cells undergoes meiosis and becomes the megaspore (female) and microspore (male). These cells do not fuse directly to be a fertilized zygote which is also different from animals. Rather, they undergo three (female) and two (male) round of mitosis to produce gamete cells. This process is called “gametogenesis”.
Double fertilization occurs only in flowering plants which is the most evolutionary advanced living things among plants. Fertilization of an egg cell (n) with a sperm cell (n) gives rise to the 2n embryo. Fertilization of an central cell (2n) with a sperm cell (n) gives rise to the 3n endosperm which is a nourishing tissue to the developing embryo. We are trying to understand these processes by genetic and epigenetic approaches.
Especially, imprinting (allele-specific differential expression) mechanism and how these imprinted genes are set epigenetically during reproduction are great interests of our laboratory. Furthermore, we study the functions of DNA methylation/demethylation, histone methylation and ubiquitination, and transcriptional repression by polycomb group protein (PcG) during reproduction. We also study how epigenetic memory is faithfully inherited during cell division and what is needed for this process.