Developmental Biology 第八章胚后生长及衰老 Post-embryonic Growth and Aging
Developmental Biology 第八章 胚后生长及衰老 Post-embryonic Growth and Aging
Developmental Biology 组织、器官、个体的生长 动物生长的主要特点 胚胎发育早期生长不明显或缓慢; 生长主要发生在个体的维形建立之后; 不同组织器官的生长速度不同
Developmental Biology 动物生长的 主要特点 ➢ 胚胎发育早期生长不明显或缓慢； ➢ 生长主要发生在个体的雏形建立之后； ➢ 不同组织器官的生长速度不同。 一、组织、器官、个体的生长
Developmental Biology 生长的策略 e.g, many Axon of neuron e.g. bone, tissues cartilage Cell Cell Growth by Fig 14.1 The three main strategies multiplication enlargement accretion for growth in vertebrates. The most common mechanism is cell proliferation -growth followed by division. A second o strategy is cell enlargement, in which cells increase their size without dividing a third strategy is to increase size by accretionary growth, such as matrix secretion 号‖◎ 损伤或刺激可诱导细胞增殖或生长: matrIx ↓ 如将大鼠肝脏切除2/3,剩余部分增殖 ○|使肝脏恢复原来的大小;切除肾的 部分,剩余部分主要通过细胞增大而 增大。 在正在生长的组织中,生长速度决 定于细胞的增殖和凋亡的速度
Developmental Biology 生长的策略 Axon of neuron e.g., bone, cartilage e.g., many tissues 损伤或刺激可诱导细胞增殖或生长： 如将大鼠肝脏切除2/3,剩余部分增殖 使肝脏恢复原来的大小；切除肾的一 部分，剩余部分主要通过细胞增大而 增大。 在正在生长的组织中，生长速度决 定于细胞的增殖和凋亡的速度
Developmental Biology 细胞增殖受内外因素的控制 Fig. 14.2 The eukaryotic cell cycle After mitosis(M), the daughter cells can either enter a resting phase(Go), in which they effectively withdraw from the cell Resting cycle, or proceed through Gt to the phase of DNA synthesis(S). This is followed by DIVISIOn G2, and then by mitosis. Cell growth occurs throughout G1, S, and G2. The decision to enter Go or to proceed through G1 IGrowth may be controlled by both intracellular factors status and extracellular signals, such as growth factors. Cells such as neurons cephas and skeletal muscle cells, which do not divide after differentiation are permanently in Go During cleavage of fertilized eg there are virtually no G-phase
Developmental Biology 细胞增殖受内外因素的控制 During cleavage of fertilized eggs, there are virtually no G-phase
Developmental Biology 果蝇胚胎早期发育中细胞的分裂特点 果蝇受精卵含母体磷酸化 蛋白 string,使1-13次卵 8 9 11 裂只发生细胞核的分裂, 15 无G期。其后,母体 string 蛋白消失,合子 string基 因按时空特异性表达,其 Fig14.3 Domains of mitosis in the表达受 gap、pair- ruled 等 Drosophila blastoderm. Mitotic domains基因产物的控制,只有表 that divide at the same time are indicated 达 string的细胞才能进入 有丝分裂。由于有丝分裂 by the various colors. The numbers ind-不同步,不同组织有不同 cate the order in which various regions 数量的细胞。 undergo mitosis at the 14th cycle. After Edgar, B.A., et al 1994
Developmental Biology 果蝇受精卵含母体磷酸化 蛋白string，使1－13次卵 裂只发生细胞核的分裂， 无G期。其后,母体string 蛋白消失，合子string基 因按时空特异性表达，其 表达受gap、pair-ruled等 基因产物的控制，只有表 达string的细胞才能进入 有丝分裂。由于有丝分裂 不同步，不同组织有不同 数量的细胞。 果蝇胚胎早期发育中细胞的分裂特点