Investigation on the origin and evolution of the diploid multicellular body plan of land plants by focusing on genes from charophycean green algae

Charophycean green algae include the closest relatives of land plants and have a gametophyte-dominant life cycle without a multicellular sporophyte generation. Although they do not produce multicellular sporophytes, they may have homologues of genes involved in sporophyte development in land plants, which may function in the multicellular gametophytes and/or the unicellular zygotes. Therefore, charophycean green algae are important in exploring the origin of genes involved in sporophyte development. Especially interesting are the relationships of such genes to genes that function in gametes and zygotes. Among the charophycean green algae, Charales and Coleochaetales are considered the closest relatives to land plants. In this study, we investigate the origin and evolution of the diploid multicellular body plan of land plants by focusing on genes from charalean algae Chara braunii.