【摘要】 线粒体在细胞中的发生目前有各种观点的争论,其理论意义涉及到真核细胞的起源和进化、染色体和线粒体两个遗传体系之间的相互关系以及生物膜合成和组装机理等。我们对处于分化中的昆虫胸肌线粒体的观察结果是:（1）对粘虫变态期的呼吸和细胞色素氧化酶活力测定表明蛹期第8天的组织形成阶段是胸肌细胞分化和其线粒体发生的开始。电镜观察表明,线粒体形成分两个阶段:由颗粒结构（可能是酶蛋白与脂的复合体）装配成膜片和膜泡;由膜泡分化出内嵴,进而发育为线粒体。（2）QO₂值,P/O比和ATP酶活力的出现与膜结构的分化发育相平行。α-甘油磷酸氧化酶系统比谷氨酸氧化酶系统装配早;电子传递酶系比磷酸化酶系装配早。（3）蝗虫胸肌分化过程的电镜观察证明;先形成内膜小泡（直径约0.1微米左右）,后形成外膜,组成简单线粒体;后者进一步分化发育为成熟线粒体。（4）QO₂值,P/O比和ATP酶活力与膜结构分化发育相平行。ATP酶的出现与能量转涣功能呈平行关系。膜形成早期和“幼稚”线粒体阶段,ATP酶尚未装配。（5）综合上述结果:线粒体膜由非膜结构逐步组装形成,线粒体内膜的各酶系组装次序不同步,线粒体DNA控制合成的膜蛋白在膜结构形成中似乎起核心和骨架作用;线粒体总组装过程在不同细胞中表现为多种途径和方式。更多还原

【Abstract】 At present it is well known that the mitochondria are formed by a close intereac-tion of two distinct genetic systems: the nucleo-cytoplasmic system and the mitochon-drial system. However, it is not quite clear how mitochondrial membranes in the cell are assembled. The present investigation provides some evidences indicating that during the process of mitochondria biogenesis in armyworm species the outer mitochondrial membrane is formed first, followed by the inner mitoehondrial membrane and crestae system; but in locust species the mitochondria biogenesis process begins with the formation of inner mitoehondrial membrane vesicles followed by the outer mitochondria] membrane. The experimental results obtained from these two insects are summarized as follows:Ⅰ. Electronmicroscopic examinations (Plates 1:1-4, 11:5-6) indicated that the mitochondria of armyworm are formed from non-membraneous precusors (macromole-cule particles). In the early stage of differentiation and development of flight muscle of this insect (8th day of pupal stage) the outer mitoehondrial membranes are just being assembled (Plate 1:1). From this period on the mitochondria develop and grow rapidly. Finally, the mitochondria of adult moth become a complicated systems with well-developed inner membranes (Plate 11:5-6). The biochemical determinations (Q02, P: O and ATPase activity) of these mitoehondrial preparations have demonstrated clearly that during the process of mitochondria genesis the change of structure corelates with a change of function. Observations on the respiratory rate of intact pupa and the cytochrome oxidase activity of pupal tissue homogenate have indicated that mitochcti-dria assembly become more active beginning from the 8th day of pupal stage. Another series of experiments has shown that in this period no oligomycin-sensitive ATPase-Fi activity can be detected. This suggests that at the early stage of mitochondria formation ATPase-F1 are not yet synthesized or they are not assembled on the inner mitochondrial membranes.Ⅱ. During the 4th instar of larval development of locust differentiation of flight muscle just begins while the mitochondria are being formed. It seems that the inner mitoehondrial membrane vesicles are formed first and then the outer mitoehondrial membrane. In accordance with these there is also a gradual increase in Qo2, P: O as well as in the oligomycin-sensitive ATPase activity from 4th instar larva to adult locust. It was also found that in the 4th instar locust larva mitochondria had no head-like F1 on the inner mitoehondrial membrane and very low oligomycin-sensitive ATPase activity was detected.From these experimental results the following points are made: the mitochondria of the developing insect flight muscle during metamorphosis are formed gradually from non-membraneous precursors, different enzymes are assembled on the inner mitoehondrial membranes at different stages of development, and the peptides synthesized by mitoehondrial genetic system seem to have more importance in the early stage of assembly of mitochondria membranes.更多还原