第15章 细胞分化与胚胎发育,Main content,Cell differentiation Basic conception Cell tortipotency Stem cell The facors affecting cell differentiation Developmental cell differentiation,Section 1: cell differentiation,脊椎动物细胞分化示意图,一、Basic conception of cell differentiation,http:/upload.wikimedia.org/wikipedia/commons/3/3c/Stem_cells_diagram.png,Cell differentiation:,The process of the cell from multicellular organism be able to differentiate into a specific cell type, in addtion, maitains its choice through many subsequent generations.,在个体发育中，由一种相同的细胞类型经由细胞分裂后逐渐在形态，结构和功能上形成稳定性差异，产生不同细胞类群的过程称为细胞分化。,（一）Cell differentiation results from gene differential expression,分子杂交技术检测基因及其mRNA 的表达,（二）House keeping gene and tissue specific gene,House keeping gene (管家基因) Expressed in all cells, their gene products are essential for cell metabolism. Replicated during the early S phase.,Tissue specific gene (组织特异性基因) Differential expressed in tissues thus keep their specific morphology, structure and function. Replicated during the early S phase in the cell where the gene is expressed. Repliacted during the late S phase in the cell where the gene is not expressed.,RT-PCR of XRRA1 and a house-keeping gene G3PDH from HCT116 clones treated with X-radiation, various cancer and normal cells, and normal tissues/organs,（二）House keeping gene and tissue specific gene,甘油醛-3-磷酸脱氢酶,（三）Combinatorial gene control creates many different cell types in Eucaryotes,（四）The single gene regulatory protein can trigger the formation of an entire organ,MyoD is a protein with a key role in regulating muscle differentiation. MyoD belongs to a family of proteins known as myogenic regulatory factors (MRFs) sharing bHLH (basic helix loop helix) structures as transcription factors.,（五）cell differentiation also be employed for the protozoan to adjust the environment,http:/19thpsalm.org/Ch09/index_files/lifecycle.gif,The life cycle of the slime molds,黏菌繁殖过程示意,（六）Transdifferentiation,Transdifferentialtion(转分化): 一种分化类型的细胞转变成另一种类型的分化细胞的现象称为转分化。,去分化： 分化细胞失去其特有结构与功能变成为未分化细胞细胞特征过程。,再分化：未分化细胞重新特化过程。,（七） Regeneration,蝾螈肢体的切除再生,Regeneration (再生） 广义再生涉及细胞，组织，器官以及个体水平。一般指生物体缺失部分后重建过程。,Main content,Cell differentiation Basic conception Cell tortipotency Stem cell The facors affecting cell differentiation Developmental cell differentiation,二, cell totipotency,细胞经分裂和分化后仍具有形成完整有机体的潜能或特性。,Plant cell totipotency,nucleus totipotency-爪蟾核移植实验,全能性细胞核 （totipotent nucleus） 终末分化细胞的细胞核仍然具有全能性 Nuclear transfer experiment 证明细胞核的全能性,nucleus totipotency- 哺乳动物体细胞核移植,Main content,Cell differentiation Basic conception Cell tortipotency Stem cell The facors affecting cell differentiation Developmental cell differentiation,三, Stem cell,Defining properties: 1, not terminally differentiated 2, divide without limit 3, its two daughter cells with the choices to be remain stem cell or be terminal differentiated,http:/trizellion.com/?page_id=40,Category of stem cell,Totipotent stem cell Pluripotent stem cell Unipotent stem cell,http:/dels-old.nas.edu/bls/stemcells/types-of-stem-cells.shtml,Differential potential,Category of stem cell,Totipotent stem cell (全能干细胞)： 具分化产生三个胚层中的各种类型的细胞，能发育成胚盘组织，产生子代个体。 如哺乳动物全能干细胞：受精卵与卵裂早期细胞。,Category of stem cell,Tortipotent stem cell Pluripotent stem cell Unipotent stem cell,http:/dels-old.nas.edu/bls/stemcells/types-of-stem-cells.shtml,Differential potential,Category of stem cell,Pluripotent stem cell (多能干细胞)： 在一定条件下，能分化产生3个胚层中的各种类型的细胞并形成器官的一类干细胞，如胚胎干细胞和生殖嵴干细胞。,Category of stem cell,Tortipotent stem cell Pluripotent stem cell Unipotent stem cell,http:/dels-old.nas.edu/bls/stemcells/types-of-stem-cells.shtml,Differential potential,Category of stem cell,Sources difference,http:/dels-old.nas.edu/bls/stemcells/types-of-stem-cells.shtml,Category of stem cell,Embryonic Stem (ES) cell : 胚胎干细胞,Adult Stem (AS) cell: 成体干细胞,Embryonic Stem Cell,人胚胎干细胞建系示意,人胚胎干细胞定向诱导分化,Embryonic Stem Cell,Producing stem cells from embryos and somatic cell nuclear transfer,http:/www.science.org.au/nova/079/079print.htm,somatic cell nuclear transfer derived stem cell,http:/dels-old.nas.edu/bls/stemcells/types-of-stem-cells.shtml,Comparison of ESC and ASC,Induced Pluripotent Stem Cell (iPS),Induced Pluripotent Stem Cell (iPS),http:/www.sigmaaldrich.com/life-science/stem-cell-biology/ipsc.html,Cell engineering,生殖性克隆 治疗性克隆 再生医学 组织工程,Main content,Cell differentiation Basic conception Cell tortipotency Stem cell The facors affecting cell differentiation Developmental cell differentiation,四, the factors affecting cell differentiation,http:/bioinformatics.bioen.illinois.edu/img/Epigenomics.png,（一）Cytoplasm nonhomogeneity from the fertilized egg for cell differentiation,隐蔽mRNA 决定子 （determinent）,果蝇卵在受精后2小时内只进行核分裂, 胞质不分裂，形成合胞体胚胎。随后核向卵边缘迁移，细胞的分化命运决定于核迁入不同的细胞质区域。迁入卵后端生殖质（germplasm）中的最终分化为生殖细胞。 证明了果蝇卵细胞后端存在决定生殖细胞分化的细胞质成分即生殖质就是 种质细胞的决定子,Figure 22-28a Molecular Biology of the Cell ( Garland Science 2008),（二）extracellular signals for cell differentiation,近端组织的相互作用（promixate tissue interaction）主要通过细胞旁分泌产生信号分子来