a proposed mechanism for the interaction of the segmentation clock and the determination front in somitogenesis拟议机制的交互分割时钟和somitogenesis的决心面前.pdfVIP

A Proposed Mechanism for the Interaction of the Segmentation Clock and the Determination Front in Somitogenesis ´ ´ 1,2 1 Moises Santillan *, Michael C. Mackey ´ ´ ´ ´ 1 Campus Monterrey, Centro de Investigacion y Estudios Avanzados del Instituto Politecnico Nacional (IPN), Apodaca, Nuevo Leon, Mexico, 2 Centre for Nonlinear ´ Dynamics, McGill University, Montreal, Quebec, Canada Abstract Background: Recent discoveries in the field of somitogenesis have confirmed, for the most part, the feasibility of the clock and wavefront model. There are good candidates for both the clock (various genes expressed cyclically in the tail bud of vertebrate embryos have been discovered) and the wavefront (there are at least three different substances, whose expression levels vary along the presomitic mesoderm [PSM], that have important effects on the formation of somites). Nevertheless, the mechanisms through which the wavefront interacts with the clock to arrest the oscillations and induce somite formation have not yet been fully elucidated. Principal Findings: In this work, we propose a gene regulatory network which is consistent with all known experimental facts in embryonic mice, and whose dynamic behaviour provides a potential explanation for the periodic aggregation of PSM cells into blocks: the first step leading to the formation of somites. Significance: To our knowledge, this is the first proposed mechanism that fully explains how a block of PSM cells can stop oscill