内容

目次

1. Formation and Differentiation of Avian Somite Derivatives... 1 BodoChrist and Martin Scaal Abstract... 1 Introduction ... 1 Dermomyotome... 2Sclerotome... 14 Outlook... 29 2. Avian Somitogenesis: Translating Time andSpace into Pa ttern... 42 Beate Brand-Saberi, Stefan Rudloff and Anton J.Gamel Abstract... 42 Introduction... 42 Epithelialization of the segmentalplate... 43 The anterior posterior polarization of the paraxial mesoderm...46 Resegmentation of the somitic derivatives... 49 Regionalization of somitesand segmental plate... 49 Oscillations in gene expression underlyingsomitogenesis... 50 Conclusion and future considerations... 52 3. Geneticanalysis of somite formation in laboratory fish models... 58 ChristophWinkler and Harun Elmasri Abstract... 58 Introduction... 58 Geneticallydissecting the clock in zebrafish: The Delta/Notch somitogenesis mutants...60 Dissecting the wave front in zebrafish: FGF signalling and Tbx24... 62Other pathways implicated in somitogenesis... 64 Medaka: a modelcomplementary to zebrafish... 64 Somite formation in the teleost medaka... 65Medaka somitogenesis mutants... 66 Medaka somite mutants with PSMprepatterning defects... 67 Medaka mutants with defective somite polarity...67 Conclusions and outlook... 69 4. Old wa res and new: five decades ofinvestigation of somitogenesis in Xenopus laevis... 73 Duncan B. SparrowAbstract... 73 Introduction... 73 Structure of the PSM... 76 Morphologicaldescriptions of segmentation in Xenopus... 77 A comparison of Xenopussegmentation with that of amniote vertebrates... 78 What controls where thesomitic furrow forms?... 78 Evidence for segmental Prepatterning of thePSM... 79 Cycling genes--evidence of a "clock"?... 81 Embryological insightsinto the nature of the "wavefront"... 85 The molecular nature of thewavefront... 86 What are the morphomechanical mechanisms required for somiteseparation?... 87 Ena/VASP... 89 Conclusion... 90 5. Role of Delta-Like-3 inMammalian Somitogenesis and Vertebral Column Formation... 95 Gavin Chapmanand Sally L. Dunwoodie Abstract... 95 Introduction... 95 Somitogenesis... 95The Notch Signalling Pathway... 97 Notch Signalling and Somite Formation...99 Dll1 and Dll3 Perform Different Functions during Somitogenesis inMammals... 102 Dll3 Conclusions and the Future... 106 6. Mesp-Fa mily Genesare Required for Segmental Pa tterning and Segmental Border Formation...113Yumiko Saga and Yu Takahashi Abstract... 113 Introduction... 113 Backgroundof Mesp1 and Mesp2... 114 Function of Mesp2 during Somitogenesis... 114 Mesp2Is also Involved in the Segment Border Formation... 118 Regulation of Mesp2Expression during Somitogenesis... 120 Functional Redundancy between Mesp1and Mesp2... 120 Mesp Genes in the Other Vertebrates... 121 Perspective...122 7. bHLH Proteins and Their Role in Somitogenesis... 124 Miguel Maroto,Tadahiro Iimura, J. Kim Dale and Yasumasa Bessho Abstract... 124Introduction... 124 The Hairy/E(Spl) Related Factors... 125 pMesogenin1Family: pMesogenin1, Mespo and cMespo... 127 The Mesp Family: Mesp, Meso andThylacine... 127 Paraxis... 131 Myogenic Regulatory Factors (MRFs)... 131bHLH Factors Involved in the Control of Myogenesis... 133 Conclusions... 1348. Mouse Mutations Disrupting Somitogenesis and Vertebral Pa tterning... 140Kenro Kusumi, William Sewell and Megan L. O'Brien Introduction... 140 NotchSignaling Pathway... 142 Canonical Wnt Signaling Pathway... 151 NoncanonicalWnt Signaling Pathway... 151 Fgf (Fibroblast Growth Factor) SignalingPathway... 152 RA (Retinoic Acid) Signaling Pathway... 152 BMP/TGF-betaSignaling Pathway... 152 Hedgehog Signaling Pathway... 152 SnailTranscriptional Repressors... 153 T-Box Transcription Factors... 153 HomeoboxTranscription Factors... 153 Paired-Box Transcription Factors... 155 ForkheadTranscription Factors... 155 Basic Helix-Loop-Helix (bHLH) TranscriptionFactors... 155 Protocadherins... 156 Other Genes... 156 Conclusion... 156 9.Defective Somitogenesis and Abnormal Vertebral Segmentation in Man... 164Peter D. Turnpenny Abstract... 164 Introduction... 164 Notch SignalingPathway Genes and Spondylocostal Dysostosis... 169 Concluding Remarks... 184InDEX...Pending