Jared Nathanson Rose Hills
Understanding the Evolution of EMF2 in Bryophytes
All land plants undergo an alternation of generations. This alternation occurs between a haploid gametophyte and a diploid sporophyte. In the early-diverging lineages of land plants, such as liverworts, hornworts, and mosses, the haploid gametophyte is dominant in the life cycle. However, in later-diverging lineages, such as gymnosperms and angiosperms, the diploid sporophyte is dominant while the haploid gametophyte is transient. It is possible that this evolution of sporophyte dominance may have been caused by a delay in Polycomb Repressive Complex 2 (PRC2)-triggered meiosis in the sporophyte generation. PRC2 functions in the trimethylation of lysine 27 on histone 3, a mark usually associated with gene silencing. By investigating the PcG gene EMBRYONIC FLOWER2 (EMF2) in bryophytes, I plan to better understand how the EMF2 gene evolved in early-diverging land plants.