Nov 18, 2005

Development of the upper lip: morphogenetic and molecular mechanisms

Developmental Dynamics : an Official Publication of the American Association of Anatomists
Rulang JiangAndrew C Lidral

Abstract

The vertebrate upper lip forms from initially freely projecting maxillary, medial nasal, and lateral nasal prominences at the rostral and lateral boundaries of the primitive oral cavity. These facial prominences arise during early embryogenesis from ventrally migrating neural crest cells in combination with the head ectoderm and mesoderm and undergo directed growth and expansion around the nasal pits to actively fuse with each other. Initial fusion is between lateral and medial nasal processes and is followed by fusion between maxillary and medial nasal processes. Fusion between these prominences involves active epithelial filopodial and adhering interactions as well as programmed cell death. Slight defects in growth and patterning of the facial mesenchyme or epithelial fusion result in cleft lip with or without cleft palate, the most common and disfiguring craniofacial birth defect. Recent studies of craniofacial development in animal models have identified components of several major signaling pathways, including Bmp, Fgf, Shh, and Wnt signaling, that are critical for proper midfacial morphogenesis and/or lip fusion. There is also accumulating evidence that these signaling pathways cross-regulate genetically as well as crosst...Continue Reading

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  • Citations96
  • References123
  • Citations96

Citations

Mentioned in this Paper

Vertebrates
Pathogenic Aspects
Entire Oral Cavity
Biochemical Pathway
Pathogenesis
Maxilla
Cleft Palate, Isolated
Cross Reactions
Gastroschisis
Embryonic Development

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