烟草受精前后胚囊中钙调素的免疫细胞化学定位

IMMUNO LOCALIZATION OF CALMODULIN IN UNFER_ TILIZED AND FERTILIZED EMBRYO SACS IN NICOTIANA TABACUM VAR.MACROPHYLLA 

应用辣根过氧化物酶标记抗体的光镜免疫细胞化学技术和胶体金标记抗体的电镜免疫细胞化学技术定位烟草（Ｎｉｃｏｔｉａｎａｔａｂａｃｕｍｖａｒ．ｍａｃｒｏｐｈｙｌａ）胚囊成员细胞中的钙调素，比较了不同类型细胞之间钙调素的分布特点，并探讨了受精前后钙调素在胚囊中分布的变化规律。

Light microscopic immunohistochemical techniques with horse radish peroxidase(HRP) conjugated second antibody and protein A gold immunoelectron microscopic techniques were used to study the distribution of calmodulin (CaM)in unfertilized and fertilized embryo sacs in Nicotiana tabacum var.macrophylla. Before fertilization, CaM was richer in the egg apparatus cells and antipodal cells than in the central cell. During the course from pollination to fertilization, the persistent synergid contained more CaM than the degenerated synergid. Meanwhile, two distinct bands rich in CaM were observed between the egg apparatus and the central cell, and gradually fused with each other appearing arc shape. When the two polar nuclei had fused, this CaM rich band began to disappear. After fertilization, CaM level was still high in the zygote and the persistent synergid but low in the endosperm cells. Although there was no evidence about the polar distribution of CaM in the zygote, distinguishable difference, however, existed between the apical cell and the basal cell of a proembryo, being higher in the former than in the latter. The function of CaM during double fertilization and early embryogenesis as well as the temopral relationship between the CaM rich band and the actin corona reported by other investigators are discussed.