Animals|Basic Helix-Loop-Helix Transcription Factors|Biological Clocks|Body Patterning|Computational Biology|Computer Simulation|Feedback, Physiological|Fibroblast Growth Factor 8|Gene Expression Regulation, Developmental|Gene Regulatory Networks|Mesoderm|Mice|Models, Biological|RNA, Messenger|Signal Transduction|Somites|Wnt3A Protein