Developmental Biol 动物克隆的程序 Cloning a sheep-the creation of Dolly Donar Ewe body cell from an adult female sheep to create a genetically Egg Provide dentical lamb named Dolly This achievement marked the first time that researchers had produced a specialied cell from an adult vertebrate (animal voth a ackbone). variations of the technique pioneered by the Scottish scientists were ixing uscd af other laboratories in 1999 in researc:h on cloning cattle and other animals. 1. A specialized ud- der cell from a ewe was placed in a so- 2. A thin pipette was cleus icontaining the ecome non- 3. The cells genes) from the agn cell fused with a spark 4. The resulting cell con- genes)of the donor dder oll and the oute 5. The cell grew into an embryo owering of the egg providers cell ed in a surrogate mother's womb Dolly the Cinn 6. The surrogate mother gave natic duplicate, or clone, of the donor eive
Developmental Biology 动物克隆的程序
Developmental Biology 2.细胞融合实验也证明了分化中遗传物质改变的可逆性 A:人肝细胞与大鼠肌细胞的融合实验 Huma Fig. 9. 4 Cell fusion shows the liver cell Rat muscle cell reversibility of gene inactivation during differentiation. A human liver ell is fused with a rat muscle cell. the exposure of the human nucleus(red) to the rat muscle cytoplasm results in the activation of muscle-specific repression of liver-specific genes in the human nucleus, Human muscle proteins Human liver cell and rat muscle cell fused are made together with rat muscle proteins This shows that the inactivation of muscle specific genes in human liver cells is not reversible Activation of human muscle gene expression Rat and human muscle proteins are produced oi--.6
Developmental Biology 2. 细胞融合实验也证明了分化中遗传物质改变的可逆性 A：人肝细胞与大鼠肌细胞的融合实验
Developmental biology 3.细胞分化状态是可以改变的 eg,两栖类肢体再生中肌细胞可转变为骨细胞;鸡视网膜表皮色素 细胞在含透明质酸酶、血清、苯硫脲的条件下培养后转变为晶体状细 胞 Fig 9.5 Transdifferentiation of retinal serum, and phenylthiourea, they lose pigment cells. A single pigmented their pigment and retinal cell character- epithelial cell from the embryonic chick istics. If cultured at a high density with retina can be grown in culture to produce ascorbic acid. they differentiate as lens a monolayer of pigmented cells. On further cells and produce the lens-specific protein culture in the presence of hyaluronidase, crystallin. After Okada, T.S.: 1992 Single differentiated pigmented cell Pigment and retinal cell characteristics lost >~~∠0 Grown in culture Monolayer of pigmented cells Change in culture conditions Transdifferentiate into lens cells Change in culture conditions
Developmental Biology 3. 细胞分化状态是可以改变的 e.g., 两栖类肢体再生中肌细胞可转变为骨细胞；鸡视网膜表皮色素 细胞在含透明质酸酶、血清、苯硫脲的条件下培养后转变为晶体状细 胞
Developmental Biology 三、DNA的不可逆改变导致的细胞分化 eg,脊椎动物免疫系统 Figure 24.3 The pool of immature lymphocytes contains B cells and T cells making antibodies and receptors with a variety of specificities. Reaction with an antigen leads to clonal expansion of the lymphocyte with the antibody (B cell) or receptor T cell) that can recognize the antigen Lymphocyte recognizes antigen Clonal expansi 上 人 人 人
Developmental Biology 三、DNA的不可逆改变导致的细胞分化 e.g., 脊椎动物免疫系统
Developmental Biology Figure 24.1 Overview: humoral immunity is conferred by the binding of free antibodies to antigens Figure 24.2 Overview in cell-mediated immunity. to form antigen-antibody complexes that are remove killer T cells use the T-cell receptor to recognize a from the bloodstream by macrophages or that are fragment of the foreign antigen which is 'presented' attacked directly by the complement proteins on the surface of the target cell by the MHC protein Bcel Secretion of antibodies 寄主细胞MHC by B cell requires helper T cells 进入细胞中的抗原 人AAA (如病毒的肽段) Antbody-antigen comple MHC presents"ant T-cell rece Macrophage T lymphocyte recognize (a complex consisting of-20 proteins
Developmental Biology 进入细胞中的抗原 (如病毒的肽段) 寄主细胞MHC (a complex consisting of ~20 proteins)