Abstract
In angiosperms, a zygote divides unequally to produce asymmetric daughter cells (apical and basal cells) with different cell fates. In some animal species, it is known that the sperm fusion site functions as signal for positional information during early embryogenesis. In the study, we analyzed relationship between sperm cell-fusion site and position of zygotic first division plane using in vitro fertilization system with rice gametes.
We stained plasma membrane of sperm cell using a fluoresceinated lectin in mineraloil mannitol drop, and the labeled sperm cell was fused with an egg cell, resulting in marking of fusion point. Since the labeled signal disappeared during zygote culture, we employed cell-fixed culture method. The result indicated that there is no relationship between sperm cell-fusion site and position of cell plate formation, suggesting that sperm-fusion site does not function as positional information for first cell cleavage of rice zygote.
