摘要
隐藻类的核形体,是存在于其质体周腔内的一个特殊细胞器。除DNA和RNA外,核形体是否含有碱性蛋白,有无核仁或核仁结构成份,以及其功能如何,国内外迄今未见报道。我们用4-6-diamidino-2-phenylindole(DAPI)荧光染色法、Uranyl acetate-EDTA-Lead染色法、碳酸氨银染色法(AS)和特异性显示核仁纤维区酸性蛋白的Ag-NOR银染法,分别在光镜和电镜下对湛江隐藻(Cryptomonas zhanjianagis Hu et Li)进行了核形体细胞化学的研究。除证实核形体中DNA、RNA和极少量碱性蛋白存在外,还首次证实了核形体中类似于核仁纤维区的酸性蛋白的存在。我们认为,隐藻的核形体,作为一个恒定的细胞结构和退化的细胞核残迹,在漫长的演化过程中可能较多地保留了核仁部分而较少地保留了其核质部分。其功能可能与隐藻色素复合体中某些蛋白质的合成有关。
Since the discovery of the nucleomorph in the chloroplast compartment of Cryptomonads (Greenwood, 1974), studies on the structure and the function of the nucleomorph have been widely carried out. Acorrding to its ultrastructure and exhibition of DNA and RNA, the nucleomorph was suggested to represent a rudimental nucleus of a primitive endosymbiont. Up to now, however, there is no evidence that the nucleomorph contains basic protein and acidic protein which usually presents in a nucleolus. Function of the nuclcomorph is also lefted to be verified.4'-6-diamidino-2-phenylindole (DAPI), Uranyl acetate-EDTA-Lead, AS and Ag-NOR stains were used in our cytochemical studies on the nucleomorph of Cryptomonas zhanjiangis. Results of the studies show that the nucleomorph contains not only DNA (Plate Ⅰ, Fig. 4) and RNA (Plate Ⅱ, Fig. 5), but also basic protein (Plate Ⅱ, Fig. 7) and acidic protein (Plate Ⅱ, Fig. 7, 8) which usually presents in the fibrous area of the nucleolus.The acidic protein illustrated by us indicates that the nucleomorph might be conccrned with the synthesis of pigment, ribosome or outer membranous protein of chloroplast complex of Cryptomonas, or some enzyme in its pyrenoid. We suggest that the nucleomorph, as a constant preserved structure, might preserved more nucleolar components and less components of nuclear matrix in its phylogeny.
出处
《实验生物学报》
CSCD
1991年第2期89-97,共9页
Acta Biologiae Experimentalis Sinica
关键词
隐藻
核形体
细胞化学
Cryptomonads. Nucleomorph. DNA. RNA. Basic protein. Acidic protein.
