Analysis of Proteins Enriched in Rice Gamete

In angiosperms, female gamete differentiation, fertilization, and subsequent zygotic development occur in embryo sacs deeply embedded in the ovaries. Despite their importance in plant reproduction and development, how the egg cell is specialized, fuses with the sperm cell, and converts into an active zygote for early embryogenesis remains unclear. Proteins enriched in each cell type are thought to reflect the biological function of the cells, since the composition of cellular proteins generally differs depending on cell type. Therefore, proteins enriched in gametes, egg and sperm cells, should have a role in reproductive and/or developmental processes, such as gamete differentiation, gamete fusion, egg activation, and early zygotic development. In this chapter, a method for identification of proteins enriched in rice gametes is first explained, and then functional analyses for these proteins using rice and Arabidopsis lines with mutations in genes encoding the putative gamete-enriched proteins are also described.