mRNA differential display was established by Liang and Pardee in 1992 for the purpose of displaying the mRNA differences between two tissues. The early embryonic development in animals is primarily controlled by the ...mRNA differential display was established by Liang and Pardee in 1992 for the purpose of displaying the mRNA differences between two tissues. The early embryonic development in animals is primarily controlled by the maternal RNAs stored in egg. These mRNAs are being degraded as the development proceeds. In some animals, such as fish and amphibian, new transcripts do not appear until the midblastula stage (midblastula transition, MBT). In other animals, for example in mouse, the zygotic genes are expressed during very early stages of development. The mRNA programmed synthesis and degradation during embryonic development controls the cell differentiation, germlayer formation and pattern formation. All these mRNA changes could be displayed side by side as cDNA band differences by mRNA differential display and the genes corresponding to these differential mRNAs could thus be obtained.展开更多
The hedgehog-patched (hh-ptc) intercellular signaling pathway has recently been shown to control the proliferation of epithelial stem cells in both Drosophila and vertebrates. Mutant and ectopic expression analyses in...The hedgehog-patched (hh-ptc) intercellular signaling pathway has recently been shown to control the proliferation of epithelial stem cells in both Drosophila and vertebrates. Mutant and ectopic expression analyses in Drosophila suggest that the HH protein diffuses from the signaling cells to promote the proliferation of nearby ovarian somatic stem cells by antagonizing the suppression of its receptor PTC towards the CI transcription factor in the stem cells. Consequently, the transcription of CIdependent genes leads to stem cell proliferation. This regulatory pathway appears to function also in vertebrates,where defects in ptc cause basal cell carcinoma, tumors of epidermal stem cell origin. Basal cell carcinoma can also be induced by ectopic expression of Sonic hedgehog (shh) or Glil, the vertebrate homolog of ci. These studies suggest the conservation of the hh signaling pathway in controlling epithelial stem cell divisions among different organisms.展开更多
Epithelial-mesenchymal transition （EMT） is initially considered as a physiological phenomenon during the embryogenesis of mammals, as well as a basic biological event maintaining the stability of the vital body. Rec...Epithelial-mesenchymal transition （EMT） is initially considered as a physiological phenomenon during the embryogenesis of mammals, as well as a basic biological event maintaining the stability of the vital body. Recent researches indicated that EMT plays a critical role in various tumors progression, through which epithelial cancers invade and metastasize. The cell characteristics are changed during EMT, in which the cells lose cell-cell and cell-matrix interactions and apical polarity, reorganize their cytoskeleton, and become isolated, motile, as well as resistant to anoikis, then become spindle-shaped mesenchymal cells. This review lays emphasis on studying the cell morphogenesis, makers and molecular mechanism regulation about EMT, discussing the relationship between the EMT and the cancer development and metastasis.展开更多
The leucine-rich repeats and PDZ (LAP) family of genes are crucial for the maintenance of cell polarity as well as for epithelial homeostasis and tumor suppression in both vertebrates and invertebrates.Four members of...The leucine-rich repeats and PDZ (LAP) family of genes are crucial for the maintenance of cell polarity as well as for epithelial homeostasis and tumor suppression in both vertebrates and invertebrates.Four members of this gene family are known:densin,erbin,scribble and lano.Here,we identified the four members of the LAP gene family in Xenopus tropicalis and studied their expression patterns during embryonic development.The Xenopus LAP proteins show a conserved domain structure that is similar to their homologs in other vertebrates.In Xenopus embryos,these genes were detected in animal cap cells at the early gastrula stage.At later stages of development,they were widely expressed in epithelial tissues that are highly polar in nature,including the neural epithelia,optic and otic vesicles,and in the pronephros.These data suggest that the roles of the Xenopus LAP genes in the control of cell polarity and morphogenesis are conserved during early development.Erbin and lano show similar expression patterns in the developing head,suggesting potential functional interactions between the two molecules in vivo.展开更多
Neurons synthesizing the neurotransmitter dopamine exert crucial functions in the mammalian brain. The biggest and most important population of dopamine-synthesizing neurons is located in the mammalian ventral midbra...Neurons synthesizing the neurotransmitter dopamine exert crucial functions in the mammalian brain. The biggest and most important population of dopamine-synthesizing neurons is located in the mammalian ventral midbrain （VM）, and controls and modulates the exe- cution of motor, cognitive, affective, motivational, and rewarding behaviours. Degeneration of these neurons leads to motor deficits that are characteristic of Parkinson＇s disease, while their dysfunction is involved in the pathogenesis of psychiatric disorders including schizophrenia and addiction. Because the aetiology and therapeutic prospects for these diseases include neurodevelopmental aspects, substantial scientific interest has been focused on deciphering the mechanistic pathways that control the generation and sur- vival of these neurons during embryonic development. Researches during the last decade revealed the pivotal role of the secreted Wntl ligand and its signaUing cascade in the generation of the dopamine-synthesizing neurons in the mammalian VM. Here, we summarize the initial and more recent findings that have unravelled several Wntl-controUed genetic networks required for the proliferation and commitment of VM progenitors to the dopaminergic cell fate during midgestational embryonic stages, and for the correct differentiation of these progenitors into postmitotic dopamine-synthesizing neurons at late midgestational embryonic and foetal stages.展开更多
Since the creation of intelligent creatures,we are no longer the puppets of the creator.For thousands of years,people have been thinking about the nature and the future of ourselves,and reconstruction of the process o...Since the creation of intelligent creatures,we are no longer the puppets of the creator.For thousands of years,people have been thinking about the nature and the future of ourselves,and reconstruction of the process of life has become the ultimate dream for us.In 1951,William Harvey,a British scientist,elaborated the theory of the structure and function of embryos for the first time in his book'the reproduction of animals',which established the foundation for people to explore the process and the mechanism of embryonic development.展开更多
文摘mRNA differential display was established by Liang and Pardee in 1992 for the purpose of displaying the mRNA differences between two tissues. The early embryonic development in animals is primarily controlled by the maternal RNAs stored in egg. These mRNAs are being degraded as the development proceeds. In some animals, such as fish and amphibian, new transcripts do not appear until the midblastula stage (midblastula transition, MBT). In other animals, for example in mouse, the zygotic genes are expressed during very early stages of development. The mRNA programmed synthesis and degradation during embryonic development controls the cell differentiation, germlayer formation and pattern formation. All these mRNA changes could be displayed side by side as cDNA band differences by mRNA differential display and the genes corresponding to these differential mRNAs could thus be obtained.
文摘The hedgehog-patched (hh-ptc) intercellular signaling pathway has recently been shown to control the proliferation of epithelial stem cells in both Drosophila and vertebrates. Mutant and ectopic expression analyses in Drosophila suggest that the HH protein diffuses from the signaling cells to promote the proliferation of nearby ovarian somatic stem cells by antagonizing the suppression of its receptor PTC towards the CI transcription factor in the stem cells. Consequently, the transcription of CIdependent genes leads to stem cell proliferation. This regulatory pathway appears to function also in vertebrates,where defects in ptc cause basal cell carcinoma, tumors of epidermal stem cell origin. Basal cell carcinoma can also be induced by ectopic expression of Sonic hedgehog (shh) or Glil, the vertebrate homolog of ci. These studies suggest the conservation of the hh signaling pathway in controlling epithelial stem cell divisions among different organisms.
基金Supported by the grants from the Natural Science Foundation of China （No. 81000998） Natural Science Foundation of Hubei Province of China （No. 2007ABA248）
文摘Epithelial-mesenchymal transition （EMT） is initially considered as a physiological phenomenon during the embryogenesis of mammals, as well as a basic biological event maintaining the stability of the vital body. Recent researches indicated that EMT plays a critical role in various tumors progression, through which epithelial cancers invade and metastasize. The cell characteristics are changed during EMT, in which the cells lose cell-cell and cell-matrix interactions and apical polarity, reorganize their cytoskeleton, and become isolated, motile, as well as resistant to anoikis, then become spindle-shaped mesenchymal cells. This review lays emphasis on studying the cell morphogenesis, makers and molecular mechanism regulation about EMT, discussing the relationship between the EMT and the cancer development and metastasis.
基金supported by the Key State Research Program from Ministry of Science and Technology of China (Grant No.2007CB947201)the State Key Laboratory of Genetic Resources and Evolution
文摘The leucine-rich repeats and PDZ (LAP) family of genes are crucial for the maintenance of cell polarity as well as for epithelial homeostasis and tumor suppression in both vertebrates and invertebrates.Four members of this gene family are known:densin,erbin,scribble and lano.Here,we identified the four members of the LAP gene family in Xenopus tropicalis and studied their expression patterns during embryonic development.The Xenopus LAP proteins show a conserved domain structure that is similar to their homologs in other vertebrates.In Xenopus embryos,these genes were detected in animal cap cells at the early gastrula stage.At later stages of development,they were widely expressed in epithelial tissues that are highly polar in nature,including the neural epithelia,optic and otic vesicles,and in the pronephros.These data suggest that the roles of the Xenopus LAP genes in the control of cell polarity and morphogenesis are conserved during early development.Erbin and lano show similar expression patterns in the developing head,suggesting potential functional interactions between the two molecules in vivo.
文摘Neurons synthesizing the neurotransmitter dopamine exert crucial functions in the mammalian brain. The biggest and most important population of dopamine-synthesizing neurons is located in the mammalian ventral midbrain （VM）, and controls and modulates the exe- cution of motor, cognitive, affective, motivational, and rewarding behaviours. Degeneration of these neurons leads to motor deficits that are characteristic of Parkinson＇s disease, while their dysfunction is involved in the pathogenesis of psychiatric disorders including schizophrenia and addiction. Because the aetiology and therapeutic prospects for these diseases include neurodevelopmental aspects, substantial scientific interest has been focused on deciphering the mechanistic pathways that control the generation and sur- vival of these neurons during embryonic development. Researches during the last decade revealed the pivotal role of the secreted Wntl ligand and its signaUing cascade in the generation of the dopamine-synthesizing neurons in the mammalian VM. Here, we summarize the initial and more recent findings that have unravelled several Wntl-controUed genetic networks required for the proliferation and commitment of VM progenitors to the dopaminergic cell fate during midgestational embryonic stages, and for the correct differentiation of these progenitors into postmitotic dopamine-synthesizing neurons at late midgestational embryonic and foetal stages.
基金supported by the National Nature Science of China(3147127791649202)National key R&D program of China(2016YFA0500901)
文摘Since the creation of intelligent creatures,we are no longer the puppets of the creator.For thousands of years,people have been thinking about the nature and the future of ourselves,and reconstruction of the process of life has become the ultimate dream for us.In 1951,William Harvey,a British scientist,elaborated the theory of the structure and function of embryos for the first time in his book'the reproduction of animals',which established the foundation for people to explore the process and the mechanism of embryonic development.
