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Molecular signaling along the anterior-posterior axis of early palate development.

Smith TM, Lozanoff S, Iyyanar PP, Nazarali AJ - Front Physiol (2013)

Bottom Line: In mammals, the palatal tissue can be distinguished into anterior bony hard palate and posterior muscular soft palate that have specialized functions in occlusion, speech or swallowing.Numerous transcription factors and signaling pathways are now recognized as either anterior- (e.g., Msx1, Bmp4, Bmp2, Shh, Spry2, Fgf10, Fgf7, and Shox2) or posterior-specific (e.g., Meox2, Tbx22, and Barx1).We hypothesize that the anterior palate acts as a signaling center in setting up development of the secondary palate.

View Article: PubMed Central - PubMed

Affiliation: Laboratory of Molecular Cell Biology, College of Pharmacy and Nutrition, University of Saskatchewan Saskatoon, SK, Canada.

ABSTRACT
Cleft palate is a common congenital birth defect in humans. In mammals, the palatal tissue can be distinguished into anterior bony hard palate and posterior muscular soft palate that have specialized functions in occlusion, speech or swallowing. Regulation of palate development appears to be the result of distinct signaling and genetic networks in the anterior and posterior regions of the palate. Development and maintenance of expression of these region-specific genes is crucial for normal palate development. Numerous transcription factors and signaling pathways are now recognized as either anterior- (e.g., Msx1, Bmp4, Bmp2, Shh, Spry2, Fgf10, Fgf7, and Shox2) or posterior-specific (e.g., Meox2, Tbx22, and Barx1). Localized expression and function clearly highlight the importance of regional patterning and differentiation within the palate at the molecular level. Here, we review how these molecular pathways and networks regulate the anterior-posterior patterning and development of secondary palate. We hypothesize that the anterior palate acts as a signaling center in setting up development of the secondary palate.

No MeSH data available.


Related in: MedlinePlus

Schematic representation for defining anterior, medial, and posterior regions of palatal shelves. Tissue anterior or posterior to first molar tooth is considered anterior or posterior palate, respectively. The palatal tissue in the region of first molar tooth bud is considered medial. Abbreviations: PP, primary palate; PS, palatal shelves; M1, first molar tooth bud.
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Figure 1: Schematic representation for defining anterior, medial, and posterior regions of palatal shelves. Tissue anterior or posterior to first molar tooth is considered anterior or posterior palate, respectively. The palatal tissue in the region of first molar tooth bud is considered medial. Abbreviations: PP, primary palate; PS, palatal shelves; M1, first molar tooth bud.

Mentions: Analysis of the literature on regionally expressed genes can be difficult since a standardized method of determining the anterior, medial, and posterior regions of the palate is not in place. Many authors fail to indicate how they define the region of the palate that they are examining making comparison difficult between articles. It is important for the field to adopt a standard convention for defining the anterior, medial, and posterior palate to ensure that these comparisons can be made. In the past, the anterior and posterior have been described in a number of ways. We propose that the convention can be followed such that the tissue anterior or posterior to the first molar tooth bud be considered the anterior or posterior palate, respectively. The medial palate would be considered palate tissue in the plane of the molar tooth bud (Figure 1). The rationale is that the first formed palatal rugae (R1) demarcates the expression boundary of anterior (e.g., Msx1, Shox2, and Fgf10) and posterior (e.g., Meox2, Tbx22) specific genes (Zhang et al., 2002; Yu et al., 2005; Li and Ding, 2007; Pantalacci et al., 2008; Welsh and O'Brien, 2009; Bush and Jiang, 2012). The first molar tooth bud lies immediately anterior to the R1, which forms the posterior boundary for anterior Fgf10 expression (Welsh et al., 2007). On the structural basis, the anterior two-thirds of the palate is the future hard palate. During rostral extension of the anterior palate from E11.5 to E14.5, the spatial relationship between R1 and the developing molar tooth bud remains unchanged (Welsh et al., 2007; Welsh and O'Brien, 2009), making the molar tooth bud an ideal convention to delineate the two structurally distinct regions of palate.


Molecular signaling along the anterior-posterior axis of early palate development.

Smith TM, Lozanoff S, Iyyanar PP, Nazarali AJ - Front Physiol (2013)

Schematic representation for defining anterior, medial, and posterior regions of palatal shelves. Tissue anterior or posterior to first molar tooth is considered anterior or posterior palate, respectively. The palatal tissue in the region of first molar tooth bud is considered medial. Abbreviations: PP, primary palate; PS, palatal shelves; M1, first molar tooth bud.
© Copyright Policy - open-access
Related In: Results  -  Collection

License
Show All Figures
getmorefigures.php?uid=PMC3539680&req=5

Figure 1: Schematic representation for defining anterior, medial, and posterior regions of palatal shelves. Tissue anterior or posterior to first molar tooth is considered anterior or posterior palate, respectively. The palatal tissue in the region of first molar tooth bud is considered medial. Abbreviations: PP, primary palate; PS, palatal shelves; M1, first molar tooth bud.
Mentions: Analysis of the literature on regionally expressed genes can be difficult since a standardized method of determining the anterior, medial, and posterior regions of the palate is not in place. Many authors fail to indicate how they define the region of the palate that they are examining making comparison difficult between articles. It is important for the field to adopt a standard convention for defining the anterior, medial, and posterior palate to ensure that these comparisons can be made. In the past, the anterior and posterior have been described in a number of ways. We propose that the convention can be followed such that the tissue anterior or posterior to the first molar tooth bud be considered the anterior or posterior palate, respectively. The medial palate would be considered palate tissue in the plane of the molar tooth bud (Figure 1). The rationale is that the first formed palatal rugae (R1) demarcates the expression boundary of anterior (e.g., Msx1, Shox2, and Fgf10) and posterior (e.g., Meox2, Tbx22) specific genes (Zhang et al., 2002; Yu et al., 2005; Li and Ding, 2007; Pantalacci et al., 2008; Welsh and O'Brien, 2009; Bush and Jiang, 2012). The first molar tooth bud lies immediately anterior to the R1, which forms the posterior boundary for anterior Fgf10 expression (Welsh et al., 2007). On the structural basis, the anterior two-thirds of the palate is the future hard palate. During rostral extension of the anterior palate from E11.5 to E14.5, the spatial relationship between R1 and the developing molar tooth bud remains unchanged (Welsh et al., 2007; Welsh and O'Brien, 2009), making the molar tooth bud an ideal convention to delineate the two structurally distinct regions of palate.

Bottom Line: In mammals, the palatal tissue can be distinguished into anterior bony hard palate and posterior muscular soft palate that have specialized functions in occlusion, speech or swallowing.Numerous transcription factors and signaling pathways are now recognized as either anterior- (e.g., Msx1, Bmp4, Bmp2, Shh, Spry2, Fgf10, Fgf7, and Shox2) or posterior-specific (e.g., Meox2, Tbx22, and Barx1).We hypothesize that the anterior palate acts as a signaling center in setting up development of the secondary palate.

View Article: PubMed Central - PubMed

Affiliation: Laboratory of Molecular Cell Biology, College of Pharmacy and Nutrition, University of Saskatchewan Saskatoon, SK, Canada.

ABSTRACT
Cleft palate is a common congenital birth defect in humans. In mammals, the palatal tissue can be distinguished into anterior bony hard palate and posterior muscular soft palate that have specialized functions in occlusion, speech or swallowing. Regulation of palate development appears to be the result of distinct signaling and genetic networks in the anterior and posterior regions of the palate. Development and maintenance of expression of these region-specific genes is crucial for normal palate development. Numerous transcription factors and signaling pathways are now recognized as either anterior- (e.g., Msx1, Bmp4, Bmp2, Shh, Spry2, Fgf10, Fgf7, and Shox2) or posterior-specific (e.g., Meox2, Tbx22, and Barx1). Localized expression and function clearly highlight the importance of regional patterning and differentiation within the palate at the molecular level. Here, we review how these molecular pathways and networks regulate the anterior-posterior patterning and development of secondary palate. We hypothesize that the anterior palate acts as a signaling center in setting up development of the secondary palate.

No MeSH data available.


Related in: MedlinePlus