Through various studies developmental biologists have been able to determine that the muscles of the back, ribs, and limbs derive from somites [5]. Somites are blocks of cells that contain distinct sections that diverge into specific types (axial or limb) of musculature and are an essential part of early vertebrate development. For many years the musculature of vertebrates was known to derive f...

Somites are transient blocks of cells that form sequentially along the antero-posterior axis of vertebrate embryos. They give rise to the vertebrae, ribs and other associated features of the trunk. In this work we develop and analyse a mathematical formulation of a version of the Clock and Wavefront model for somite formation, where the clock controls when the boundaries of the somites form and...

Somitogenesis is a fundamental segmentation process that forms the vertebrate body plan. A network of transcription factors is essential in establishing the spatial temporal order of this process. One such transcription factor is mesp-ba which has an important role in determining somite boundary formation. Its expression in somitogenesis is tightly regulated by the transcriptional activator Tbx...

A myofiber hyperplastic quail line P has been developed through selection for heavy body weight. Since the number of muscle fibers is determined early in development and skeletal muscle originates from somites, we compared somite formation and muscle-specific gene expression in P- and control C-line quail embryos. At 47 hours of incubation, C embryos had 18 somite pairs and P embryos had 14.3. ...

Microsurgical, tissue grafting and in situ hybridization techniques have been used to investigate the role of the neural tube and notochord in the control of the myogenic bHLH genes, QmyoD, Qmyf5, Qmyogenin and the cardiac alpha-actin gene, during somite formation in stage 12 quail embryos. Our results reveal that signals from the axial neural tube/notochord complex control both the activation ...

We have previously reported that exposure to cadmium during zebrafish embryonic development caused morphological malformations of organs and ectopic expression of genes involved in regulating developmental process. One of the most common developmental defects observed was altered axial curvature resulting from defects in the myotomes of the somites. In this study, we investigated the mechanisms...

In vertebrates all skeletal muscles of trunk and limbs are derived from condensations of the paraxial mesoderm, the somites. Limb muscle precursor cells migrate during embryogenesis from somites to limb buds where migration stops and differentiation occurs. We have characterized lbx1 homeobox genes in chicken and mice and found them to be expressed in migrating limb muscle precursor cells in bo...

DNA methylation constitutes an important epigenetic factor in the control of genetic information. In this study, we analyzed expression of the DNA methyltransferase gene and examined DNA methylation patterns during early development of the zebrafish. Maternal transcripts of the zebrafish DNA methyltransferase gene (MTase) are ubiquitously present at high levels in early embryos with overall lev...

The number of vertebrae is defined strictly for a given species and depends on the number of somites, which are the earliest metameric structures that form in development. Somites are formed by sequential segmentation. The periodicity of somite segmentation is orchestrated by the synchronous oscillation of gene expression in the presomitic mesoderm (PSM), termed the "somite segmentation clock,"...

The Notch signaling pathway has multifarious functions in the organization of the developing vertebrate embryo. One of its most fundamental roles is in the emergence of the regular pattern of somites that will give rise to the musculoskeletal structures of the trunk. The parts it plays in the early operation of the segmentation clock and the later definition and differentiation of the somites a...