Moving genes through parasitism

Abstract

Parasite Genomes Plants that parasitize other plants include species such as mistletoe and members of the endophytic family Rafflesiaceae, which have the largest flowers of any plant but no other recognizable external structures. The impact of extreme host dependency usually results in genome streamlining. Cai et al. assembled the genome of the parasitic Rafflesia Sapria himalayana , hosts of which include members of the grape family. This parasite shows rapid genome evolution that has resulted in extensive gene loss in the chloroplast and photosynthetic machinery but retention of key genes for other organs. Unexpectedly, it has gained extensive repeat regions, resulting in a substantially larger genome than its closest free-living relatives, which may reflect horizontal gene transfer occurring during ancestral host associations. Curr. Biol. 10.1016/j.cub.2020.12.045 (2021).