Submitted to: Encyclopedia of Life Sciences
Publication Type: Review article
Publication Acceptance Date: 9/14/2009
Publication Date: 1/15/2010
Citation: Boavida, L.C., Mccormick, S.M. 2010. A22316 Gametophyte and sporophyte (version 2.0). Encyclopedia of Life Sciences. DOI: 10.1002/9780470015902.a0002037.pub2 Interpretive Summary: This encyclopedia entry explains the life cycle of plants, which alternate between a diploid generation and a haploid generation.
Technical Abstract: Gametogenesis is the process of gamete formation, which includes micro- and megagametogenesis. Gametogenesis initiates after specialized cells in the sporophyte undergo meiosis, and subsequent mitotic divisions yield the gametophytic phase of the plant life cycle. In higher plants, microgametogenesis occurs in the anther, producing tricellular pollen with two sperm cells within a vegetative cell. Megagametogenesis occurs in the ovule, producing an embryo sac. The male gametes, the two sperm cells, and the female gametes, the egg and central cell, fuse to yield the zygote and the endosperm, respectively. Both micro- and megagametogenesis are under strict genetic control. Studies of gametophytic mutants have identified genes important for gametogenesis. Furthermore, high-throughput expression profiling techniques have helped identify gene regulatory networks that operate during gametogenesis.