[Neurosurgical embryology. Part 1: Cell differentiation].
In pluricellular organisms, cell differentiation helps to decrease the total amount of energy needed for life. These differentiations can be evidenced at the tissular, the cellular or the molecular levels. Cell differentiation is a progressive process achieved during embryogenesis; different steps in the program can be described. One of the explanations to account for cell differentiation is the specific expression of proteins, called transcription factors, that can control the expression of selected genes. These factors are classified according to their biochemical pattern allowing description of several families of transcription factors. One of the salient questions during embryogenesis is to understand the mechanisms involved in cell differentiation. The first event is due to asymmetry of mitosis leading to the generation of two cell lineages. This is favored by the initial ovocyte polarization. The second event is due to cell interactions (namely inductions). These inductions may be explained either by cell-cell contact (favored by cell adhesion molecules) or by secreting factors that can be either hydrophilic or lipophilic.
Catala
M
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Laboratoire d'Histologie et Embryologie et UMR CNRS 7000, Faculté de Médecine Pitié-Salpêtrière--Université Paris 6. catala@ext.jussieu.fr
D000818:Animals; D002454:Cell Differentiation; D002462:Cell Membrane / Q000235:genetics; D004268:DNA-Binding Proteins / Q000235:genetics; D004622:Embryo, Mammalian / Q000378:metabolism*; D004626:Embryology / Q000379:methods*; D004627:Embryonic Induction; D018257:Helix-Loop-Helix Motifs / Q000235:genetics; D006801:Humans; D016023:Integrins / Q000235:genetics; D051379:Mice; D008938:Mitosis / Q000502:physiology; D009493:Neurosurgery / Q000379:methods*; D050809:POU Domain Factors; D011506:Proteins; D014157:Transcription Factors / Q000235:genetics; D029961:Zebrafish Proteins / Q000235:genetics; D016335:Zinc Fingers / Q000235:genetics
C406869:Cyhr1 protein, mouse; D004268:DNA-Binding Proteins; D016023:Integrins; D050809:POU Domain Factors; D011506:Proteins; D014157:Transcription Factors; D029961:Zebrafish Proteins; C079852:pou6f1 protein, zebrafish