Figure 5.
The Prdm16Gt683Lex mutation causes recessive CP, and reporter expression in craniofacial structures is consistent with this phenotype. (A–F) Histological analysis of coronal sections through the medial aspect of the secondary palate and the primary palate in heterozygous control and homozygous Prdm16Gt683Lex E13.5 and E14.5 embryos. Reporter expression is dose-sensitive. (A and D) At E13.5, before palate shelf elevation and fusion, Prdm16 reporter expression is strongest in the mesenchyme at the oral side of the palate shelves (ps), although it is visible throughout the palate shelf and hinge region. Expression within the tongue (T) musculature, molar tooth mesenchyme (m) and within Meckel's cartilage (MC) and surrounding perichondrium is also detected. Expression in palate epithelia is difficult to detect. (B and E) This expression pattern is maintained at E14.5, after palate shelf elevation and fusion, although it appears weaker. Black arrow, shown in B, depicts epithelial seam at the point of fusion between the palate shelves. Prdm16 expression levels are highest in the primary palate (C and F).