Abstract
In angiosperms, a zygote generally divides into an asymmetric two-celled embryo consisting of an apical and a basal cell. The asymmetric cell division of the zygote is the possible first step for formation of the apical-basal axis of plants, and a fundamental feature of early embryogenesis and morphogenesis in angiosperms. In the study, using rice in vitro fertilization system and single-cell microarray analyses, we identified genes that are up- or down-regulated in the apical or basal cell of rice two-celled embryos. Approximately, 14,000 genes were expressed in rice zygotes and, among the transcripts from 14,000 genes, 0.5-1 % transcripts were detected only in apical or basal cell. These suggest that specific mRNAs are distributed with polar fashion in a zygote or degraded in one of the daughter cells of a two-celled embryo.
