Cell lineage tracing reveals early‑segregated germline in plants

August Weismann's germ plasm theory of the late 19th century posited that only germ cells, e.g., sperm and egg cells in animals or pollen and ovule cells in plants, transmit genetic information to the next generation, and that somatic mutations represent an evolutionary dead end. This theory has been highly validated in animals, whose germ cells are formed and segregated early in the organism's development.